Electrum – Bitcoin Wiki - #Adessonews Finanziamenti ...

Bitcoin Forum - bitcoinforum.com

We are [Bitcoin Forum](https://bitcoinforum.com). Bitcoin is an open-source peer-to-peer digital currency project. P2P means that there is no central authority to issue new money or keep track of transactions.
[link]

BitcoinPrivate

[link]

The Market Place - An Anonymous Market Built To Enable Trustless Transactions.

The Marketplace, the secure anonymous marketplace built to enable safe trustless transactions.
[link]

Electrum Wiki (hosted on Orain) is redirecting to PornHub /r/Bitcoin

Electrum Wiki (hosted on Orain) is redirecting to PornHub /Bitcoin submitted by BitcoinAll to BitcoinAll [link] [comments]

Bitcoin Newcomers FAQ - Please read!

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
It all started with the release of the release of Satoshi Nakamoto's whitepaper however that will probably go over the head of most readers so we recommend the following videos for a good starting point for understanding how bitcoin works and a little about its long term potential:
Some other great resources include Lopp.net, the Princeton crypto series and James D'Angelo's Bitcoin 101 Blackboard series.
Some excellent writing on Bitcoin's value proposition and future can be found at the Satoshi Nakamoto Institute.
Some Bitcoin statistics can be found here and here. Developer resources can be found here. Peer-reviewed research papers can be found here.
Potential upcoming protocol improvements and scaling resources here and here.
The number of times Bitcoin was declared dead by the media can be found here (LOL!)

Key properties of Bitcoin

Where can I buy bitcoins?

Bitcoin.org and BuyBitcoinWorldwide.com are helpful sites for beginners. You can buy or sell any amount of bitcoin (even just a few dollars worth) and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also check out the bitcoinity exchange resources for a larger list of options for purchases.
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy OTP Auth
Android Android N/A
iOS iOS iOS

Watch out for scams

As mentioned above, Bitcoin is decentralized, which by definition means there is no official website or Twitter handle or spokesperson or CEO. However, all money attracts thieves. This combination unfortunately results in scammers running official sounding names or pretending to be an authority on YouTube or social media. Many scammers throughout the years have claimed to be the inventor of Bitcoin. Websites like bitcoin(dot)com and the btc subreddit are active scams. Almost all altcoins (shitcoins) are marketed heavily with big promises but are really just designed to separate you from your bitcoin. So be careful: any resource, including all linked in this document, may in the future turn evil. Don't trust, verify. Also as they say in our community "Not your keys, not your coins".

Where can I spend bitcoins?

Check out spendabit or bitcoin directory for millions of merchant options. Also you can spend bitcoin anywhere visa is accepted with bitcoin debit cards such as the CashApp card. Some other useful site are listed below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Spendabit, Overstock and The Bitcoin Directory Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, LivingRoomofSatoshi, Coinsfer, and more Bill payment
Menufy, Takeaway and Thuisbezorgd NL Takeout delivered to your door
Expedia, Cheapair, Destinia, Abitsky, SkyTours, the Travel category on Gyft and 9flats For when you need to get away
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun Domain name registration
Stampnik Discounted USPS Priority, Express, First-Class mail postage
Coinmap and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. If you would prefer to keep it simple there are several good options. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, Cryptogrind, Coinality, Bitgigs, /Jobs4Bitcoins, BitforTip, Rein Project Freelancing
Lolli Earn bitcoin when you shop online!
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
/GirlsGoneBitcoin NSFW Adult services
A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins.

Bitcoin-Related Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network Second layer scaling
Blockstream, Rootstock and Drivechain Sidechains
Hivemind and Augur Prediction markets
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
JoinMarket and Wasabi Wallet CoinJoin implementation
Coinffeine and Bisq Decentralized bitcoin exchanges
Keybase Identity & Reputation management
Abra Global P2P money transmitter network
Bitcore Open source Bitcoin javascript library

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
bitcoin BTC 1 bitcoin one bitcoin is equal to 100 million satoshis
millibitcoin mBTC 1,000 per bitcoin used as default unit in recent Electrum wallet releases
bit bit 1,000,000 per bitcoin colloquial "slang" term for microbitcoin (μBTC)
satoshi sat 100,000,000 per bitcoin smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $10000 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit.
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BitcoinFan7 to Bitcoin [link] [comments]

Cant send from Localbitcoins to Electrum. ELI5 Bitcoin address inter-operability?

When I tried to send from Localbitcoins to Electrum it failed even though I thought Local had upgraded 2 years ago. I sent it elsewhere so didn't need to solve that issue. Why is it still not working?
https://en.bitcoin.it/wiki/Address explaining the address formats:
There are currently three address formats in use:
P2PKH which begin with the number 1, eg: 1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2
P2SH type starting with the number 3, eg: 3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy
Bech32 type starting with bc1, eg: bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq
What kind of sending/receiving from which types of addresses will not work?
submitted by fap_fap_fap_fapper to BitcoinBeginners [link] [comments]

Storing your coins safely while not risking loss of keys

This was originally an answer to a question that was asked here, but OP deleted their post.
This might help some newbies (especially the multisig edit at the end), so I want to make sure it's still accessible here.
The original question was whether the Electrum wallet stores a Trezor's private key when using a passphrase.
OP noticed that their Trezor wouldn't connect to their Electrum wallet when entering a different passphrase than they used when creating the wallet. Thus, OP (likely) assumed that the wallet stored the private key, as it somehow knew that a different private key was now used.
Here is my original answer (with some modifications):
IMPORTANT: I'm assuming here that you connected your Trezor by choosing the "hardware wallet" option in Electrum, rather than giving Electrum your 12/24 seed words.
TL;DR: No, your coins are safe :)
I'm assuming by passphrase) you mean the 25th (or 13th) word. When you have this feature enabled, a private key gets generated every time you enter a passphrase. When you enter the same passphrase you used to create the wallet, the wallet with your funds shows up.
Whenever you enter something different, a different private key is generated on your Trezor. This allows you to have multiple different wallets, for example by choosing the passphrases "First Wallet", "Second Wallet", "Third Wallet", or a secret wallet with a secret passphrase.
So whenever you enter a new passphrase when connecting your Trezor to Electrum, the Trezor will send a new public key to Electrum. Electrum will then derive addresses from this public key and check those for balances. It won't find any, as you used a new passphrase.
EDIT: I just realized that you said your wallet doesn't connect to Electrum when you use a different passphrase. This is simply because Electrum doesn't receive the correct public key from the Trezor and therefore Electrum thinks it's a different wallet (which it is).
When you enter the passphrase you used during creation of your wallet, the Trezor will send your actual public key to Electrum, which will then find addresses with balances, which it will show to you. EDIT (to clarify): Connecting your Trezor after creating the wallet is only necessary to send funds or verify addresses, as the public key is already stored in the wallet.dat.
The only thing Electrum actually stores is the public key, which can only be used to look at your Bitcoin, not to move them. You might want to keep this public key a secret as well though, since it links all your funds to you. This is what Electrum stores in the wallet.dat file, which you can just encrypt by choosing a password for it.
Well done using a passphrase by the way! Should someone get their hands on your Trezor, a sophisticated attacker can get the secret key off the device in 15 minutes. Using a passphrase makes this attack almost useless, as the both secret key AND the passphrase are needed to move your funds, and the passphrase is not stored on the device. A passphrase also allows you to hide funds from potential robbers that force you to unlock your wallet.
You can do this by activating the passphrase feature and sending your funds to a wallet with a secret passphrase (do NOT lose this, as losing your passphrase renders your funds inaccessible). Afterwards, you can safely deactivate the passphrase feature, so the device doesn't even ask for one should you get robbed. Simply reactivate it when you need to access your funds.
EDIT: Should you be worried that you might forget your passphrase, you should look into multisig wallets. Depending on how you set this up, you can make it more secure against theft and less likely for you to lose access to your funds.
Say for example you get four wallets: two hardware wallets, a well-protected (airgapped) laptop with Electrum, and a secure mobile wallet that allows for multisig (like Fully Noded).
You can then create a 2-of-4 multisig wallet that requires you to sign transactions with any two of these four wallets.
The increase in security comes from the fact that an attacker now needs full access to two of your devices (or their stored private keys) at once.
At the same time, the fact that you yourself now also need access to only half of your devices means that in the event of a total loss of one (or even two) of them, you can still move your funds to a new wallet.
As long as you do regular checks (e.g. first day of each month), ensuring that you still have access to all your devices' stored private keys, you can always catch a loss of keys and fix this without losing funds (by creating a new multisig wallet and sending the funds there).
This allows you to use a passphrase on your wallets without storing it anywhere physically or digitally. This would usually be very risky, as forgetting the passphrase would lead to a loss of funds, but this risk is now close to eliminated.
(The following part was not in the original answer)
Some IMPORTANT general secruity tips:
  1. Consider including trusted friends and/or family members as co-signers for a multisig wallet. This ensures that it's not even possible for you alone to hand over funds to an attacker. Depending on your level of trust, you might want to make sure that your co-signers can't collaborate to steal your funds (if you include 3 people, create at least a 4-of-n multisig). You could also deliberately make it possible for all or even just some of your co-signers to move your funds (3 co-signers, 3(or less)-of-n multisig) to make sure your funds aren't lost should pass away unexpectedly.
  2. Consider running your own full node and Electrum server (also check the alternatives), which you connect your Electrum wallet to. This ensures that you don't send your public key to anyone else. If someone knows your public key, they know how much BTC you own, making you a potential target.
  3. Always encrypt your wallet.dat (or whatever you called your wallet file), even if it's a watch-only wallet. This protects your public key (see 1. for why you want that).
  4. Create watch-only wallets: Use an airgapped) device to create a wallet with Electrum (make sure to back up the seed phrase) and export the public key. Then create a new watch-only wallet on another device (like your everyday laptop) with that public key to be able to check your funds. To create the initial wallet, you can also use any other hard- or software wallet that allows you to export the master public key.
  5. Hide, or (when using a hardware wallet with a passphrase) even delete your watch-only wallets. Hiding your funds makes you less of a target. When using a hardware wallet, recreating the watch-only wallet is fast and simple, so you don't need to store it if you don't want to check your funds every day. Note that this approach doesn't help much when you don't use a passphrase, as an attacker will obviously check the passphrase-less wallet no matter what.
  6. Keep some funds on your hardware wallet(s). If an attackers sees funds on the wallet(s), they might not force you to enter a passphrase or ask if you have any multisig wallets (lying under pressure is hard).
  7. Hide all your wallets in different places. If someone sees that you have multiple wallets lying around, they might realize you have a multisig wallet.
  8. Don't risk a robber getting (for example) two keys to your 2-of-4 multisig wallet and then racing them to move your funds with the other two keys when they leave. They're gonna come back and be pissed. If it comes to this, you need protection until the robber is caught. STAY SAFE!
  9. The easiest way to solve a problem is to never have it. Don't make yourself a target. If nobody even suspects that you have a multisig (or any wallet at all), they're probably not gonna look for it.
Please correct any mistakes you find and I will edit my post. I will also gladly add more tips to the list. I will of course credit anyone who helps.
Tip for devs who want something cool and important to work on: Make the creation and usage of multisig wallets as noob-friendly as possible. If someone expresses worries about losing access to their funds by forgetting the seed phrase, wallet pin, etc. (someone in my family actually brought this up to me), multisig wallets are the perfect solution as they add redundancy.
submitted by Fittiboy to Bitcoin [link] [comments]

Syscoin Platform’s Great Reddit Scaling Bake-off Proposal

Syscoin Platform’s Great Reddit Scaling Bake-off Proposal

https://preview.redd.it/rqt2dldyg8e51.jpg?width=1044&format=pjpg&auto=webp&s=777ae9d4fbbb54c3540682b72700fc4ba3de0a44
We are excited to participate and present Syscoin Platform's ideal characteristics and capabilities towards a well-rounded Reddit Community Points solution!
Our scaling solution for Reddit Community Points involves 2-way peg interoperability with Ethereum. This will provide a scalable token layer built specifically for speed and high volumes of simple value transfers at a very low cost, while providing sovereign ownership and onchain finality.
Token transfers scale by taking advantage of a globally sorting mempool that provides for probabilistically secure assumptions of “as good as settled”. The opportunity here for token receivers is to have an app-layer interactivity on the speed/security tradeoff (99.9999% assurance within 10 seconds). We call this Z-DAG, and it achieves high-throughput across a mesh network topology presently composed of about 2,000 geographically dispersed full-nodes. Similar to Bitcoin, however, these nodes are incentivized to run full-nodes for the benefit of network security, through a bonded validator scheme. These nodes do not participate in the consensus of transactions or block validation any differently than other nodes and therefore do not degrade the security model of Bitcoin’s validate first then trust, across every node. Each token transfer settles on-chain. The protocol follows Bitcoin core policies so it has adequate code coverage and protocol hardening to be qualified as production quality software. It shares a significant portion of Bitcoin’s own hashpower through merged-mining.
This platform as a whole can serve token microtransactions, larger settlements, and store-of-value in an ideal fashion, providing probabilistic scalability whilst remaining decentralized according to Bitcoin design. It is accessible to ERC-20 via a permissionless and trust-minimized bridge that works in both directions. The bridge and token platform are currently available on the Syscoin mainnet. This has been gaining recent attention for use by loyalty point programs and stablecoins such as Binance USD.

Solutions

Syscoin Foundation identified a few paths for Reddit to leverage this infrastructure, each with trade-offs. The first provides the most cost-savings and scaling benefits at some sacrifice of token autonomy. The second offers more preservation of autonomy with a more narrow scope of cost savings than the first option, but savings even so. The third introduces more complexity than the previous two yet provides the most overall benefits. We consider the third as most viable as it enables Reddit to benefit even while retaining existing smart contract functionality. We will focus on the third option, and include the first two for good measure.
  1. Distribution, burns and user-to-user transfers of Reddit Points are entirely carried out on the Syscoin network. This full-on approach to utilizing the Syscoin network provides the most scalability and transaction cost benefits of these scenarios. The tradeoff here is distribution and subscription handling likely migrating away from smart contracts into the application layer.
  2. The Reddit Community Points ecosystem can continue to use existing smart contracts as they are used today on the Ethereum mainchain. Users migrate a portion of their tokens to Syscoin, the scaling network, to gain much lower fees, scalability, and a proven base layer, without sacrificing sovereign ownership. They would use Syscoin for user-to-user transfers. Tips redeemable in ten seconds or less, a high-throughput relay network, and onchain settlement at a block target of 60 seconds.
  3. Integration between Matic Network and Syscoin Platform - similar to Syscoin’s current integration with Ethereum - will provide Reddit Community Points with EVM scalability (including the Memberships ERC777 operator) on the Matic side, and performant simple value transfers, robust decentralized security, and sovereign store-of-value on the Syscoin side. It’s “the best of both worlds”. The trade-off is more complex interoperability.

Syscoin + Matic Integration

Matic and Blockchain Foundry Inc, the public company formed by the founders of Syscoin, recently entered a partnership for joint research and business development initiatives. This is ideal for all parties as Matic Network and Syscoin Platform provide complementary utility. Syscoin offers characteristics for sovereign ownership and security based on Bitcoin’s time-tested model, and shares a significant portion of Bitcoin’s own hashpower. Syscoin’s focus is on secure and scalable simple value transfers, trust-minimized interoperability, and opt-in regulatory compliance for tokenized assets rather than scalability for smart contract execution. On the other hand, Matic Network can provide scalable EVM for smart contract execution. Reddit Community Points can benefit from both.
Syscoin + Matic integration is actively being explored by both teams, as it is helpful to Reddit, Ethereum, and the industry as a whole.

Proving Performance & Cost Savings

Our POC focuses on 100,000 on-chain settlements of token transfers on the Syscoin Core blockchain. Transfers and burns perform equally with Syscoin. For POCs related to smart contracts (subscriptions, etc), refer to the Matic Network proposal.
On-chain settlement of 100k transactions was accomplished within roughly twelve minutes, well-exceeding Reddit’s expectation of five days. This was performed using six full-nodes operating on compute-optimized AWS c4.2xlarge instances which were geographically distributed (Virginia, London, Sao Paulo Brazil, Oregon, Singapore, Germany). A higher quantity of settlements could be reached within the same time-frame with more broadcasting nodes involved, or using hosts with more resources for faster execution of the process.
Addresses used: 100,014
The demonstration was executed using this tool. The results can be seen in the following blocks:
612722: https://sys1.bcfn.ca/block/6d47796d043bb4c508d29123e6ae81b051f5e0aaef849f253c8f3a6942a022ce
612723: https://sys1.bcfn.ca/block/8e2077f743461b90f80b4bef502f564933a8e04de97972901f3d65cfadcf1faf
612724: https://sys1.bcfn.ca/block/205436d25b1b499fce44c29567c5c807beaca915b83cc9f3c35b0d76dbb11f6e
612725: https://sys1.bcfn.ca/block/776d1b1a0f90f655a6bbdf559ff5072459cbdc5682d7615ff4b78c00babdc237
612726: https://sys1.bcfn.ca/block/de4df0994253742a1ac8ac9eec8d2a8c8b0a6d72c53d6f3caa29bb6c171b0a6b
612727: https://sys1.bcfn.ca/block/e5e167c52a9decb313fbaadf49a5e34cb490f8084f642a850385476d4ef10d70
612728: https://sys1.bcfn.ca/block/ab64d989edc71890e7b5b8491c20e9a27520dc45a5f7c776d3dae79057f59fe7
612729: https://sys1.bcfn.ca/block/5e8b7ecd0e36f99d07e4ea6e135fc952bf7ec30164ab6f4d1e98b0f2d405df6d
612730: https://sys1.bcfn.ca/block/d395df3d31dde60bbb0bece6bd5b358297da878f0beb96be389e5f0e043580a3
It is important to note that this POC is not focused on Z-DAG. The performance of Z-DAG has been benchmarked within realistic network conditions: Whiteblock’s audit is publicly available. Network latency tests showed an average TPS around 15k with burst capacity up to 61k. Zero-latency control group exhibited ~150k TPS. Mainnet testing of the Z-DAG network is achievable and will require further coordination and additional resources.
Even further optimizations are expected in the upcoming Syscoin Core release which will implement a UTXO model for our token layer bringing further efficiency as well as open the door to additional scaling technology currently under research by our team and academic partners. At present our token layer is account-based, similar to Ethereum. Opt-in compliance structures will also be introduced soon which will offer some positive performance characteristics as well. It makes the most sense to implement these optimizations before performing another benchmark for Z-DAG, especially on the mainnet considering the resources required to stress-test this network.

Cost Savings

Total cost for these 100k transactions: $0.63 USD
See the live fee comparison for savings estimation between transactions on Ethereum and Syscoin. Below is a snapshot at time of writing:
ETH price: $318.55 ETH gas price: 55.00 Gwei ($0.37)
Syscoin price: $0.11
Snapshot of live fee comparison chart
Z-DAG provides a more efficient fee-market. A typical Z-DAG transaction costs 0.0000582 SYS. Tokens can be safely redeemed/re-spent within seconds or allowed to settle on-chain beforehand. The costs should remain about this low for microtransactions.
Syscoin will achieve further reduction of fees and even greater scalability with offchain payment channels for assets, with Z-DAG as a resilience fallback. New payment channel technology is one of the topics under research by the Syscoin development team with our academic partners at TU Delft. In line with the calculation in the Lightning Networks white paper, payment channels using assets with Syscoin Core will bring theoretical capacity for each person on Earth (7.8 billion) to have five on-chain transactions per year, per person, without requiring anyone to enter a fee market (aka “wait for a block”). This exceeds the minimum LN expectation of two transactions per person, per year; one to exist on-chain and one to settle aggregated value.

Tools, Infrastructure & Documentation

Syscoin Bridge

Mainnet Demonstration of Syscoin Bridge with the Basic Attention Token ERC-20
A two-way blockchain interoperability system that uses Simple Payment Verification to enable:
  • Any Standard ERC-20 token to be moved from Ethereum to the Syscoin blockchain as a Syscoin Platform Token (SPT), and back to Ethereum
  • Any SPT to be moved from Syscoin to the Ethereum blockchain as an ERC-20 token, and back to Syscoin

Benefits

  • Permissionless
  • No counterparties involved
  • No trading mechanisms involved
  • No third-party liquidity providers required
  • Cross-chain Fractional Supply - 2-way peg - Token supply maintained globally
  • ERC-20s gain vastly improved transactionality with the Syscoin Token Platform, along with the security of bitcoin-core-compliant PoW.
  • SPTs gain access to all the tooling, applications and capabilities of Ethereum for ERC-20, including smart contracts.
https://preview.redd.it/l8t2m8ldh8e51.png?width=1180&format=png&auto=webp&s=b0a955a0181746dc79aff718bd0bf607d3c3aa23
https://preview.redd.it/26htnxzfh8e51.png?width=1180&format=png&auto=webp&s=d0383d3c2ee836c9f60b57eca35542e9545f741d

Source code

https://github.com/syscoin/?q=sysethereum
Main Subprojects

API

Tools to simplify using Syscoin Bridge as a service with dapps and wallets will be released some time after implementation of Syscoin Core 4.2. These will be based upon the same processes which are automated in the current live Sysethereum Dapp that is functioning with the Syscoin mainnet.

Documentation

Syscoin Bridge & How it Works (description and process flow)
Superblock Validation Battles
HOWTO: Provision the Bridge for your ERC-20
HOWTO: Setup an Agent
Developer & User Diligence

Trade-off

The Syscoin Ethereum Bridge is secured by Agent nodes participating in a decentralized and incentivized model that involves roles of Superblock challengers and submitters. This model is open to participation. The benefits here are trust-minimization, permissionless-ness, and potentially less legal/regulatory red-tape than interop mechanisms that involve liquidity providers and/or trading mechanisms.
The trade-off is that due to the decentralized nature there are cross-chain settlement times of one hour to cross from Ethereum to Syscoin, and three hours to cross from Syscoin to Ethereum. We are exploring ways to reduce this time while maintaining decentralization via zkp. Even so, an “instant bridge” experience could be provided by means of a third-party liquidity mechanism. That option exists but is not required for bridge functionality today. Typically bridges are used with batch value, not with high frequencies of smaller values, and generally it is advantageous to keep some value on both chains for maximum availability of utility. Even so, the cross-chain settlement time is good to mention here.

Cost

Ethereum -> Syscoin: Matic or Ethereum transaction fee for bridge contract interaction, negligible Syscoin transaction fee for minting tokens
Syscoin -> Ethereum: Negligible Syscoin transaction fee for burning tokens, 0.01% transaction fee paid to Bridge Agent in the form of the ERC-20, Matic or Ethereum transaction fee for contract interaction.

Z-DAG

Zero-Confirmation Directed Acyclic Graph is an instant settlement protocol that is used as a complementary system to proof-of-work (PoW) in the confirmation of Syscoin service transactions. In essence, a Z-DAG is simply a directed acyclic graph (DAG) where validating nodes verify the sequential ordering of transactions that are received in their memory pools. Z-DAG is used by the validating nodes across the network to ensure that there is absolute consensus on the ordering of transactions and no balances are overflowed (no double-spends).

Benefits

  • Unique fee-market that is more efficient for microtransaction redemption and settlement
  • Uses decentralized means to enable tokens with value transfer scalability that is comparable or exceeds that of credit card networks
  • Provides high throughput and secure fulfillment even if blocks are full
  • Probabilistic and interactive
  • 99.9999% security assurance within 10 seconds
  • Can serve payment channels as a resilience fallback that is faster and lower-cost than falling-back directly to a blockchain
  • Each Z-DAG transaction also settles onchain through Syscoin Core at 60-second block target using SHA-256 Proof of Work consensus
https://preview.redd.it/pgbx84jih8e51.png?width=1614&format=png&auto=webp&s=5f631d42a33dc698365eb8dd184b6d442def6640

Source code

https://github.com/syscoin/syscoin

API

Syscoin-js provides tooling for all Syscoin Core RPCs including interactivity with Z-DAG.

Documentation

Z-DAG White Paper
Useful read: An in-depth Z-DAG discussion between Syscoin Core developer Jag Sidhu and Brave Software Research Engineer Gonçalo Pestana

Trade-off

Z-DAG enables the ideal speed/security tradeoff to be determined per use-case in the application layer. It minimizes the sacrifice required to accept and redeem fast transfers/payments while providing more-than-ample security for microtransactions. This is supported on the premise that a Reddit user receiving points does need security yet generally doesn’t want nor need to wait for the same level of security as a nation-state settling an international trade debt. In any case, each Z-DAG transaction settles onchain at a block target of 60 seconds.

Syscoin Specs

Syscoin 3.0 White Paper
(4.0 white paper is pending. For improved scalability and less blockchain bloat, some features of v3 no longer exist in current v4: Specifically Marketplace Offers, Aliases, Escrow, Certificates, Pruning, Encrypted Messaging)
  • 16MB block bandwidth per minute assuming segwit witness carrying transactions, and transactions ~200 bytes on average
  • SHA256 merge mined with Bitcoin
  • UTXO asset layer, with base Syscoin layer sharing identical security policies as Bitcoin Core
  • Z-DAG on asset layer, bridge to Ethereum on asset layer
  • On-chain scaling with prospect of enabling enterprise grade reliable trustless payment processing with on/offchain hybrid solution
  • Focus only on Simple Value Transfers. MVP of blockchain consensus footprint is balances and ownership of them. Everything else can reduce data availability in exchange for scale (Ethereum 2.0 model). We leave that to other designs, we focus on transfers.
  • Future integrations of MAST/Taproot to get more complex value transfers without trading off trustlessness or decentralization.
  • Zero-knowledge Proofs are a cryptographic new frontier. We are dabbling here to generalize the concept of bridging and also verify the state of a chain efficiently. We also apply it in our Digital Identity projects at Blockchain Foundry (a publicly traded company which develops Syscoin softwares for clients). We are also looking to integrate privacy preserving payment channels for off-chain payments through zkSNARK hub & spoke design which does not suffer from the HTLC attack vectors evident on LN. Much of the issues plaguing Lightning Network can be resolved using a zkSNARK design whilst also providing the ability to do a multi-asset payment channel system. Currently we found a showstopper attack (American Call Option) on LN if we were to use multiple-assets. This would not exist in a system such as this.

Wallets

Web3 and mobile wallets are under active development by Blockchain Foundry Inc as WebAssembly applications and expected for release not long after mainnet deployment of Syscoin Core 4.2. Both of these will be multi-coin wallets that support Syscoin, SPTs, Ethereum, and ERC-20 tokens. The Web3 wallet will provide functionality similar to Metamask.
Syscoin Platform and tokens are already integrated with Blockbook. Custom hardware wallet support currently exists via ElectrumSys. First-class HW wallet integration through apps such as Ledger Live will exist after 4.2.
Current supported wallets
Syscoin Spark Desktop
Syscoin-Qt

Explorers

Mainnet: https://sys1.bcfn.ca (Blockbook)
Testnet: https://explorer-testnet.blockchainfoundry.co

Thank you for close consideration of our proposal. We look forward to feedback, and to working with the Reddit community to implement an ideal solution using Syscoin Platform!

submitted by sidhujag to ethereum [link] [comments]

Just can't figure out splitting


Ok so im not the most technically minded person even though ive been involved in crypto for a long time so forgive my ignorance.
During the bitcoin cash hardfork I had a number of bch sitting on my trezor. I read and reread the documentation about how to do the split using the electrum cash wallet: https://wiki.trezor.io/How_to_split_and_send_your_Bitcoin_Cash_forks I didnt feel confident as it seemed confusing. I'd asked a number of 'crypto businesses' in London and online for assistance over the last 18 months. I offered to pay for their time but no-one either could or would help. So I tried to follow the instructions but I was unable to find SV chains either automatically or by entering them manually
I had transferred all my bch to the electrum cash wallet by this time. Unable to follow the instructions I foolishly downloaded the electrum sv wallet, set it up and sent the funds there. The electrum sv wallet shows the correct balance and says its connected but when Ive attempted to send funds it sends me to: https://faucet.satoshisvision.network to gather some dust from a faucet (wtf) and then shows some kind of error message. -Ive clearly not split the coins correctly-
I did yet another deep dive on google and found that exodus wallet claims they can do the split with a couple of clicks. I then somehow transferred my bch to the exodus wallet from my trezor wallet (though I thought I had already sent them to electron cash). The bch shows up fine in Exodus but when I attempt to claim bitcoin sv it says: Unfortunately you do not have any Bitcoin SV.
Ive not tried to exchange the bch on exodus in case that further complicates the issue.
I'm now in the position I feared even more stuck than before and still unable to claim the bsv. Can someone please help me get out of this uber confusing problem?
submitted by Kooky_Technology_226 to bitcoincashSV [link] [comments]

Do most ATMs support bitcoin URIs?

Electrum QR codes for addresses are actually bitcoin URIs. Can most ATMs grok those?
submitted by d3vrandom to BitcoinBeginners [link] [comments]

Are seed wallets software dependant?

https://en.bitcoin.it/wiki/Paper_wallet says, paper wallets are not safe enough and recommends seed wallets.
What I don't understand: Seed wallets are dependant on the wallet software aren't they? So if I create a seed wallet with Electrum Coinomi now, hodl the coins, and in ten years Coinomi ist not existant anymore, my btc might be gone. Or am I wrong about that?
submitted by Entebe to Bitcoin [link] [comments]

FinderOuter: the bitcoin recovery tool

Link: https://github.com/Coding-Enthusiast/FinderOuter
The FinderOuter is a bitcoin recovery tool that focuses on making the recovery process easy for everyone. There is no need to read long guide pages to learn how to use the application. Instead it will always be as easy as filling some boxes, maybe selecting some options and clicking a button all in a user-friendly GUI. Each recovery option is written from scratch and all parts down to the basic cryptography used (such as SHA, ECC,...) are specialized for maximum efficiency.

Available options

1. Message signature verification

User can enter a message signature here to verify it. In case there is a problem with the message (except being an actually invalid signature), the code can search to find the common issues that some signing tools have and fix them.

2. Missing Base-58 characters

This option helps recover any base-58 encoded string with a checksum that is missing some characters. For example a damaged paper wallet where some characters are erased/unreadable. The position of missing characters must be known. It works for (1) WIFs (Base-58 encoded private key) (2) Addresses (Base-58 encoded P2PKH address) (3) BIP-38 (Base-58 encoded encrypted private key).
There is also a "special case" where a compressed private key is missing 3 characters at unknown positions.

3. Missing Base-16 characters

This option is similar to previous feature but works for base-16 (hexadecimal) private keys. It currently requires an address and only checks compressed public keys. Unlike the other options, this one is very slow since it depends on ECC and that is not yet optimized.

4. Missing mini-privatekey characters

This option is similar to 2 and 3 but works for mini-privatekeys (eg. SzavMBLoXU6kDrqtUVmffv). It requires an address to check each possible key against, as a result it is also slower since it depends on ECC and has 2 additional hashes.

5. Missing mnomonic (seed) words

This option works for BIP-39 mnemonics (others like Electrum will be added in the future) that have some words missing. It requires knowing one child key or address created from that seed and the exact path of it.

Future plans

submitted by Coding_Enthusiast to Autarkysoft [link] [comments]

Calculate txn_id from raw txn_hex

I'm trying to calculate a txn_id from raw txn_hex. The procedure works fine for legacy TXNs but gets non-expected results on Segwit TXNs. I compared this snippet of code to what txn_id was produced by Electrum and the blockchain.com TXN decoder:
  1. Take in TXN in hex
  2. Convert the hex to binarray
  3. Double hash binarray
  4. Reverse the resultant digest because of endianness
  5. Display in hex.
t0 is my legacy testnet TXN and t1 is my segwit testnet TXN.
Thoughts?

UPDATE

Found the relevant source in Electrum transaction.py:1036
Basically you strip the flags and tx_witnesses listed in the wiki spec
```python

!/usbin/env python3

[repo] https://github.com/brianddk/reddit ... python/txn_hash.py

[ref] https://www.reddit.com/g4hvyf

from hashlib import sha256
def txid(tx): bin = bytes.fromhex(tx) txid = sha256(sha256(bin).digest()).digest()[::-1].hex() return txid

Raw Legacy

t0 = ('0200000001cd3b93f5b24ae190ce5141235091cd93fbb2908e24e5b9ff6776ae' 'c11b0e04e5000000006b4830450221009f156db3585c19fe8e294578edbf5b5e' '4159a7afc3a7a00ebaab080dc25ecb9702202581f8ae41d7ade2f06c9bb9869e' '42e9091bafe39290820438b97931dab61e140121030e669acac1f280d1ddf441' 'cd2ba5e97417bf2689e4bbec86df4f831bf9f7ffd0fdffffff010005d9010000' '00001976a91485eb47fe98f349065d6f044e27a4ac541af79ee288ac00000000')

Raw Segwit

t1 = ('0200000000010100ff121dd31ead0f06e3014d9192be8485afd6459e36b09179' 'd8c372c1c494e20000000000fdffffff013ba3bf070000000017a914051877a0' 'cc43165e48975c1e62bdef3b6c942a38870247304402205644234fa352d1ddbe' 'c754c863638d2c26abb9381966358ace8ad7c52dda4250022074d8501460f4e4' 'f5ca9788e60afafa1e1bcbf93e51529defa48317ad83e069dd012103adc58245' 'cf28406af0ef5cc24b8afba7f1be6c72f279b642d85c48798685f86200000000')

UPDATE Raw Segwit with flags and tx_witnesses stripped

t2 = ('02000000' '0100ff121dd31ead0f06e3014d9192be8485afd6459e36b09179' 'd8c372c1c494e20000000000fdffffff013ba3bf070000000017a914051877a0' 'cc43165e48975c1e62bdef3b6c942a3887' '00000000')
print(f"t0: {txid(t0)}\nt1: {txid(t1)}\nt2: {txid(t2)}")

TXN_IDs from the above python

t0: cb33472bcaed59c66fae30d7802b6ea2ca97dc33c6aad76ce2e553b1b4a4e017

t1: b11fdde7e3e635c7f15863a9399cca42d46b5a42d87f4e779dfd4806af2401ce

t2: d360581ee248be29da9636b3d2e9470d8852de1afcf3c3644770c1005d415b30

TXN_IDs from Electrum

t0: cb33472bcaed59c66fae30d7802b6ea2ca97dc33c6aad76ce2e553b1b4a4e017

t1: d360581ee248be29da9636b3d2e9470d8852de1afcf3c3644770c1005d415b30

```
submitted by brianddk to Bitcoin [link] [comments]

What's Happening At Dash? | Continually Updated News & Announcements Thread

Welcome to dashpay!
If you are new to Dash, we encourage you to check out our wiki, where the Dash project is explained from the ground up with many links to valuable information resources. Also check out the menu bar on top and the sidebar to the right. We have very active Discord and Telegram channels where the community is happy to answer any and all newcomer questions.

Purpose of this post

This post is directed towards community members who wish to rapidly access information on current developments surrounding the Dash cryptocurrency.
Lately we've noticed how the pace of events picked up significantly within the Dash project due to many years of hard work coming together and pieces falling into place ("Evolution" is finally here. It's called Dash Platform). For the purpose of keeping these many pieces of information together, however, singular Reddit submissions are insufficient. Thus we decided to maintain a pinned thread collecting blog posts, interviews, articles, podcasts, videos & announcements. Check back regularly, as this thread will always feature the latest news around Dash, while also serving as a mid-term archive for important announcements and developments.
Journalists looking for news and contact opportunities wrt Dash, please bookmark:

Dash Press Room

"At Dash Press Room you will find the latest press releases, media materials and product updates on Dash - Digital Cash."

Dash Platform Video Series (formerly known as "Evolution") with Amanda B. Johnson

  1. Dash is Becoming a Cloud | Dash Platform #1
  2. What is Dash Drive? | Dash Platform #2
  3. What is Dash's Decentralized API? (DAPI) | Dash Platform #3
  4. Usernames & Dash Platform Name Service (DPNS) | Dash Platform #4

Dash Core Group News

(last updated: Oct 9th, 2020)

Dash Insights with Mark Mason & Dash Talk with Amanda B. Johnson

(last updated: Oct 9th, 2020)

Development news

(last updated: Oct 9th, 2020)

Adoption, Partnership, Business Development, General News

(last updated: Oct 3rd, 2020)
submitted by Basilpop to dashpay [link] [comments]

Impossible to split BSV from BCH on Trezor with Mac. Race against time...

No wonder why BSV value is surging, If many are struggling with a Trezor like me...
Followed this guide: https://wiki.trezor.io/How_to_split_and_send_your_Bitcoin_Cash_forks
turned out that it works only with pre 3.3.2 Electron Cash SW. Later versions don't see SV servers anymore. Besides developer warns you from using that old version it produces an error on the SV network after successfully moving coins on BCH network. (Step 11 in guide)
"error: {'code': 1, 'message': 'the transaction was rejected by network rules.\n\n258: txn-mempool-conflict\n
A race against time.
SV block height catching-up with BCH transaction block. Don't know what to do anymore in this SV limbo state....
UPDATE: Thanks to u/-johoe for the replay protection workaround below
SOLUTION: It might has to do with the recent SV Genesis fork. After all sorts of unsuccessful troubleshooting attempts the solution is quite simple: Protect your BCash for replay attack and Just wait for the BSV block height to catch up with the BCH block height of the BCH transaction. Redo the transfer on the BSV side. Bingo! Successful split.
Mac OSX 10.12.6, Electrum Cash 3.3.2 Trezor with current updated firmware
Note: ElectrumSV doesn't not support OSX 10.12.6
submitted by Dirk_Diggler- to TREZOR [link] [comments]

r/Bitcoin recap - July 2019

Hi Bitcoiners!
I’m back with the 31st monthly Bitcoin news recap.
For those unfamiliar, each day I pick out the most popularelevant/interesting stories in Bitcoin and save them. At the end of the month I release them in one batch, to give you a quick (but not necessarily the best) overview of what happened in bitcoin over the past month.
You can see recaps of the previous months on Bitcoinsnippets.com
A recap of Bitcoin in July 2019
Adoption
Development
Security
Mining
Business
Education
Regulation & Politics
Archeology (Financial Incumbents)
Price & Trading
Fun & Other
submitted by SamWouters to Bitcoin [link] [comments]

/r/Bitcoin FAQ - Newcomers please read

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
The following videos are a good starting point for understanding how bitcoin works and a little about its long term potential:
For some more great introductory videos check out Andreas Antonopoulos's YouTube playlists, he is probably the best bitcoin educator out there today. Also have to give mention to James D'Angelo's Bitcoin 101 Blackboard series. Lots of additional video resources can be found at the videos wiki page or /BitcoinTV.
Key properties of bitcoin
Some excellent writing on Bitcoin's value proposition and future can be found here. Bitcoin statistics can be found here, here and here. Developer resources can be found here and here. Peer-reviewed research papers can be found here. The number of times Bitcoin was declared dead by the media can be found here. Scaling resources here, and of course the whitepaper that started it all.

Where can I buy bitcoins?

BuyBitcoinWorldwide.com and Howtobuybitcoin.io are helpful sites for beginners. You can buy or sell any amount of bitcoin and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also, check out the bitcoinity exchange resources for a larger list of options for purchases.
Bank Transfer Credit / Debit card Cash
Coinbase Coinbase LocalBitcoins
Gemini Bitstamp LibertyX
GDAX Bitit Mycelium LocalTrader
Bitstamp Cex.io BitQuick
Kraken CoinMama WallofCoins
Xapo BitcoinOTC
Cex.io
itBit
Bitit
Bitsquare
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Cashila or Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Android iOs Desktop
Mycelium BreadWallet Electrum
CoPay AirBitz Armory
Another interesting use case for physical storage/transfer is the Opendime. Opendime is a small USB stick that allows you to spend Bitcoin by physically passing it along so it's anonymous and tangible like cash.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account, usually from a text message or app, making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy
Android Android
iOS iOS

Where can I spend bitcoins?

A more comprehensive list can be found at the Trade FAQ but some more commons ones are below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Steam, HumbleBundle, Games Planet, itch.io, g2g and kinguin For when you need to get your game on
Microsoft Xbox games, phone apps and software
Spendabit, The Bitcoin Shop, Overstock, DuoSearch, The Bitcoin Directory and BazaarBay Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Cashila, Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, Pey.de, LivingRoomofSatoshi, Hyphen.to, Coinsfer, GetPaidinBitcoin, Coins.co.th, More #1, #2 Bill payment
Foodler, Menufy, Takeaway, Thuisbezorgd NL, Pizza For Coins Takeout delivered to your door!
Expedia, Cheapair, Lot, Destinia, BTCTrip, Abitsky, SkyTours, Fluege the Travel category on Gyft and 9flats For when you need to get away
BoltVM, BitHost VPS service
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun For new domain name registration
Stampnik and GetUSPS Discounted USPS Priority, Express, First-Class mail postage
Reddit Gold Premium membership which can be gifted to others
Coinmap, 99Bitcoins and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations, such as Wikipedia, Red Cross, Amnesty International, United Way, ACLU and the EFF. You can find a longer list here.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. Bitseed is an easy option for getting set up. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, XBTfreelancer, Cryptogrind, Bitlancerr, Coinality, Bitgigs, /Jobs4Bitcoins, Rein Project Freelancing
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
Watchmybit, Streamium.io, OTika.tv, XOtika.tv NSFW, /GirlsGoneBitcoin NSFW Video Streaming
Bitasker, BitforTip, WillPayCoin Tasks
Supload.com, SatoshiBox, JoyStream, File Army File/Image Sharing
CoinAd, A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins)

Bitcoin Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network, Amiko Pay, and Strawpay Payment channels for network scaling
Blockstream and Drivechain Sidechains
21, Inc. Open source library for the machine payable web
ShapeShift.io Trade between bitcoins and altcoins easily
Open Transactions, Counterparty, Omni, Open Assets, Symbiont and Chain Financial asset platforms
Hivemind and Augur Prediction markets
Mirror Smart contracts
Mediachain Decentralized media library
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
Samourai and Dark Wallet - abandoned Privacy-enhancing wallets
JoinMarket CoinJoin implementation (Increase privacy and/or Earn interest on bitcoin holdings)
Coinffeine and Bitsquare Decentralized bitcoin exchanges
Keybase and Bitrated Identity & Reputation management
Bitmesh and Telehash Mesh networking
JoyStream BitTorrent client with paid seeding
MORPHiS Decentralized, encrypted internet
Storj and Sia Decentralized file storage
Streamium and Faradam Pay in real time for on-demand services
Abra Global P2P money transmitter network
bitSIM PIN secure hardware token between SIM & Phone
Identifi Decentralized address book w/ ratings system
Coinometrics Institutional-level Bitcoin Data & Research
Blocktrail and BitGo Multisig bitcoin API
Bitcore Open source Bitcoin javascript library
Insight Open source blockchain API
Leet Kill your friends and take their money ;)

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
millibitcoin mBTC 1,000 per bitcoin SI unit for milli i.e. millilitre (mL) or millimetre (mm)
microbitcoin μBTC 1,000,000 per bitcoin SI unit for micro i.e microlitre (μL) or micrometre (μm)
bit bit 1,000,000 per bitcoin Colloquial "slang" term for microbitcoin
satoshi sat 100,000,000 per bitcoin Smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $500 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit. A complete list of bitcoin related subreddits can be found here
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BinaryResult to Bitcoin [link] [comments]

[IDEA] [PROPOSAL] Monero Debian (deb) packages / Debian package repository deb.getmonero.org (I can do)

I have the skills to implement this if wanted.
Possible User Experience
This is a proposal, i.e. not implemented yet. Instructions for users, simplified.
How to install monero using apt-get
Download the repository signing key.
wget https://www.getmonero.org/monero.asc
Add the signing key.
sudo apt-key --keyring /etc/apt/trusted.gpg.d/monero.gpg add ~/monero.asc
Add APT repository.
echo "deb https://deb.getmonero.org buster main" | sudo tee /etc/apt/sources.list.d/monero.list
Update your package lists.
sudo apt-get update
Install monero.
sudo apt-get install monero
A few technical implementation details
I would simply grab the binaries provided by getmonero.org, download them, check software (gpg) signatures, put these into deb packages, add these to a repository, and upload the repository.
What I would not do is creating the binaries during package creation. While this is nice to have, it doesn't help user experience and blocks the progress on reaching this goal. See next chapter.
Why simply put the pre-build Monero binaries into a deb package?
1) After bitcoin existing for more than 10 years, being popular and being in Debian unstable (sid) it still never made its way into Debian testing, let alone stable. Reason being explained that a difference in underlying libraries (even just security fixes) during compilation may result in a network split. Binaries compiled during packaging on different versions of Linux distributions might have different libraries that might cause a network fork / chain split.
References:
(Note: above website saying Tags: fixed-upstream is probably a mistake as discussion at bottom says.)
2) The github issue of packaging monero stalled.
3) By shipping the same binaries as provided by getmonero.org reduces the chances of introducing a backdoor.
Many Options
Timeline
Doable quickly. The electrum (bitcoin) AppImage was recently added to a Debian package (binaries-freedom) by me and is now easily installable in Whonix. Pre-installed in testers version of Whonix already.
About Me
I am the founder of Whonix, which I am maintaining at present for more than 7 years.
Whonix (formerly TorBOX) is a Debian GNU/Linux–based security-focused Linux distribution. It aims to provide privacy, security and anonymity on the internet.
You can see an overview of packages I am maintaining on my github profile.
To proof that this forum account adrelanos corresponds the same person maintaining whonix.org, it is added here.
Questions
What happened to, what is the successor of the forum funding system?
submitted by adrelanos to Monero [link] [comments]

/r/Bitcoin FAQ - Newcomers please read

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
Some great introductions for new users are My first bitcoin, Bitcoin explained and ELI5 Bitcoin. Also, the following videos are a good starting point for understanding how bitcoin works and a little about its long term potential:
Also have to give mention to Lopp.net, the Princeton crypto series and James D'Angelo's Bitcoin 101 Blackboard series. Some excellent writing on Bitcoin's value proposition and future can be found at the Satoshi Nakamoto Institute. Bitcoin statistics can be found here, here and here. Developer resources can be found here, here and here. Peer-reviewed research papers can be found here. Potential upcoming protocol improvements here. Scaling resources here. The number of times Bitcoin was declared dead by the media can be found here (LOL!), and of course Satoshi Nakamoto's whitepaper that started it all! :)
Key properties of bitcoin

Where can I buy bitcoins?

Bitcoin.org, BuyBitcoinWorldwide.com and Howtobuybitcoin.io are helpful sites for beginners. You can buy or sell any amount of bitcoin and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also, check out the bitcoinity exchange resources for a larger list of options for purchases.
Bank Transfer Credit / Debit card Cash
Gemini Bitstamp LocalBitcoins
Bitstamp Bitit Mycelium LocalTrader
BitFinex Cex.io LibertyX
Cex.io CoinMama WallofCoins
Xapo Spectrocoin BitcoinOTC
Kraken Luno BitQuick
itBit
HitBTC
Bitit
Bisq (decentralized)
Luno
Spectrocoin
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Android iOs Desktop
Samouari BreadWallet Electrum
Another interesting use case for physical storage/transfer is the Opendime. Opendime is a small USB stick that allows you to spend Bitcoin by physically passing it along so it's anonymous and tangible like cash.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account, usually from a text message or app, making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy
Android Android
iOS iOS

Where can I spend bitcoins?

Check out spendabit or bitcoin directory for some good options, some of the more commons ones are listed below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Steam, HumbleBundle, Games Planet, itch.io, g2g and kinguin For when you need to get your game on
Microsoft Xbox games, phone apps and software
Spendabit, Overstock, The Bitcoin Directory and BazaarBay Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, LivingRoomofSatoshi, Hyphen.to, Coinsfer, More #1, #2 Bill payment
Menufy, Takeaway, Thuisbezorgd NL, Pizza For Coins Takeout delivered to your door!
Expedia, Cheapair, Lot, Destinia, BTCTrip, Abitsky, SkyTours, Fluege the Travel category on Gyft and 9flats For when you need to get away
BitHost VPS service
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun For new domain name registration
Stampnik Discounted USPS Priority, Express, First-Class mail postage
Reddit Gold Premium membership which can be gifted to others
Coinmap and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations, such as Wikipedia, United Way, ACLU and the EFF. You can find a longer list here.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. Bitseed is an easy option for getting set up. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, XBTfreelancer, Cryptogrind, Bitlancerr, Coinality, Bitgigs, /Jobs4Bitcoins, Rein Project Freelancing
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
Streamium.io, XOtika.tv NSFW, /GirlsGoneBitcoin NSFW Video Streaming
Bitasker, BitforTip Tasks
Supload.com, SatoshiBox, JoyStream, File Army File/Image Sharing
CoinAd, A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins)

Bitcoin Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network, Amiko Pay, and Strawpay Payment channels for network scaling
Blockstream, Rootstock and Drivechain Sidechains
21, Inc. Open source library for the machine payable web
ShapeShift.io Trade between bitcoins and altcoins easily
Open Transactions, Counterparty, Omni, Open Assets, Symbiont and Chain Financial asset platforms
Hivemind and Augur Prediction markets
Mediachain Decentralized media library
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
Samourai and Dark Wallet - abandoned Privacy-enhancing wallets
JoinMarket CoinJoin implementation (Increase privacy and/or Earn interest on bitcoin holdings)
Coinffeine and Bisq Decentralized bitcoin exchanges
Keybase and Bitrated Identity & Reputation management
Telehash Mesh networking
JoyStream BitTorrent client with paid seeding
MORPHiS Decentralized, encrypted internet
Storj and Sia Decentralized file storage
Streamium Pay in real time for on-demand services
Abra Global P2P money transmitter network
bitSIM PIN secure hardware token between SIM & Phone
Identifi Decentralized address book w/ ratings system
BitGo Multisig bitcoin API
Bitcore Open source Bitcoin javascript library
Insight Open source blockchain API
Leet Kill your friends and take their money ;)

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
millibitcoin mBTC 1,000 per bitcoin SI unit for milli i.e. millilitre (mL) or millimetre (mm)
microbitcoin μBTC 1,000,000 per bitcoin SI unit for micro i.e microlitre (μL) or micrometre (μm)
bit bit 1,000,000 per bitcoin Colloquial "slang" term for microbitcoin
satoshi sat 100,000,000 per bitcoin Smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $10000 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit. A complete list of bitcoin related subreddits can be found here
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BinaryResult to Bitcoin [link] [comments]

Obvious case of Blockstream & Bitcoin Core product placement? (article series on privacy & cryptocurrencies)

In a 4-part series, Eric Wall neatly demonstrates how to do product placement for Blockstream, Bitcoin Core and their affiliates including the usual troupe of BS/Core "experts".
Note: "article series by the Human Rights Foundation (HRF) on privacy and cryptocurrency, funded by the Zcash Foundation".
Don't get me wrong, there is plenty good information contained in the articles linked below. But the product placement of Bitcoin Core, Lightning, Liquid and "Green", could hardly be more obvious. For an article series "on privacy and cryptocurrencies", there is a heavy focus on BTC except in a single part (III) where the privacy coins Zcash, Monero, Grin and Beam are examined.
I recommend you read the articles. Below I've pointed out certain items that are mentioned and linked frequently within each article.
Privacy and Cryptocurrency, Part I: How Private is Bitcoin?
Privacy and Cryptocurrency, Part II: Bitcoin Wallets
  • website: bitcoin.org (get started)
  • wallet: Bitcoin Core
  • wallet: Wasabi
  • wallet: Armory
  • wallet: mSigna
  • wallet: Bitcoin Knots
  • wallet: Electrum
  • person: Peter Todd
  • person: Jameson Lopp
  • person: Udi Wertheimer
  • person: Hampus Sjöberg
  • hardware wallet: Trezor
  • hardware wallet: Ledger
  • payment server: BTCPay Server
  • payment code service: PayNym.is (made by Samourai)
  • 2nd layer: Lightning Network
  • sidechain: Liquid (by Blockstream)
  • wallet: Blockstream Green (linked via blockstream site)
  • wallet: Samourai (linked via it's own site)
  • wallet: BRD (linked via bitcoin.org!)
  • wallet: Schildbach (linked via bitcoin.org!)
  • mailing list: bitcoin-dev (run by Bitcoin Core people)
Privacy and Cryptocurrency, Part III: Should You Use a Privacy Coin?
  • Lightning
  • Liquid
  • coin: Monero
  • coin: Zcash
  • coin: Grin
  • coin: Beam
  • person: Daniel Lehnberg (Grin)
  • person: Andrew Poelstra (Blockstream, MimbleWimble)
  • person: Guy Corem.(Beam)
  • person: Ian Miers (Zcash)
  • person: Francisco Cabañas (Monero)
Privacy and Cryptocurrency, Part IV: Stablecoins— Blacklists and Traceability
  • coin: USDT on Liquid
  • wallet: Blockstream Green
  • Lightning Network (for future support of Liquid tokens like USDT)
  • person: Jameson Lopp
  • person: Matt Odell
As we can see, every article prominently highlights of Blockstream or Bitcoin Core affiliated products, persons or related companies. And every article studiously omits any mention of Bitcoin Cash or any of the privacy technologies built on it (CashShuffle) or in development on it (CashFusion), or the stable coin USDH operating on top of Bitcoin Cash.
There are certainly other cryptocurrencies and projects on them which offer privacy features, but are left unexamined in this series (e.g. projects offering privacy on ETH, mixing in Dash, etc)
In conclusion the intentions ascribed to the HRF in the first article.
The intention of the Human Rights Foundation is to examine these technologies and elucidate on their potential of bringing economic and political freedom to the individual. While there are many angles in the context of money that are within the scope of such an endeavor, we’ve chosen to focus on the topic of privacy foremost. In that pursuit it’s also clear that the degree to which cryptocurrencies enable privacy is not by any means trivial or binary — it varies greatly depending on the user’s particular choice of core and ancillary technologies and usage patterns, as well as the capabilities and sophistication of the attacker.
submitted by DarthBacktrack to btc [link] [comments]

A tutorial for Tails linux, to stay safe on Internet.

I'm not so sure this will be a help or not, quite sure that official guide is more reliable than this. anyway that's what I have here. If this article contains any kinds of misleading or error, please let me know in the comments.
A tutorial for tails linux, to stay safe on the Internet.
In today's circumstances, it's good to put more effort on maintain a low profile on Internet, or atleast learn how to do that.
If you already have a computer at home, you need to consider to use Tails linux if safety is what your concern about.
Access to https://tails.boum.org/ then follow download instructions.
The idea of tails is, it will anonymize your entire connection on Internet by using Tor network. So no one will discover your identity without lots of effort.
Not only that, once you do shutdown your device, it no longer holds any information. That means, other one can't find any evidence from your device.
Also if you still want to storage some text on tails, The easiest way is hide that in online email account.
At first, open text editor that preinstalled in tails. https://www.reddit.com/tails/comments/bm65w7/tails_faq_what_happened_to_the_pgp_clipboard_in/?utm_medium=android_app&utm_source=share
Then, follow the instruction to encrypt your text by passwords and paste it on email account through tor browser. Do not use that account to communicate to others, just keep it in secret. https://tails.boum.org/doc/encryption_and_privacy/gpgapplet/passphrase_encryption/index.en.html
If you are about to send messages through email, this instruction could be handy. https://tails.boum.org/doc/encryption_and_privacy/gpgapplet/public-key_cryptography/index.en.html You needs to learn about PGP first, tho.use XMPP is the either easier or safer plan.
You can encrypt other type of files by using Archive manager(give a right click on the file), but the computer gets freeze by that occasionally.
I strongly recommend to use Veracrypt hidden volume instead of build a Persistent storage feature, or LUCKS encrypted drive for linux that available on tails for both send/storage purposes.
In that way, you'll get two of passwords for one encrypted storage. If you are forced to reveal your password by others, you have a option to reveal a fake one.
On top of that, if you use another USB for that purpose, you don't have to slow down Tails itself. Persistent storage is tends to be fragile, I occasionally toast an entire data during excessive use. https://www.veracrypt.fen/Hidden%20Volume.html https://tails.boum.org/doc/encryption_and_privacy/veracrypt/index.en.html
You need to use other OSs for create new volumes. Linux is safer than windows I guess, but it takes an effort.
IIRC, you should check "I use hidden volume" radio button during type the password. Otherwise your hidden password doesn't simply work. Don't get confused by that.
Not only that, Tails has the Mac address spoofing function by default. Mac address is the unique identifier for your device. https://en.m.wikipedia.org/wiki/MAC_address
That function also increases anonymity on Internet. it's important when you go outside because even if you killed GPS function on your devices, it still leave a Mac address on wifi router or 3G/LTE cellular module nearby. So someone still can trace your location.
Also just in case if your government decides to not allow you to connect tor network, you should read this article first. https://tails.boum.org/doc/first_steps/startup_options/bridge_mode/index.en.html
But if every each of instruction seems failed to helps you, bring your device(with Mac address spoofing function) outside and connect to the Free wifi. https://freetoursbyfoot.com/where-find-free-wifi-london/
It's relatively safe since either of wifi or device doesn't leave the information that directly leads to you, but be aware on surveillance camera nearby. don't stay there too long, or use one spot too frequently.
I know laptops is too cumbersome to carry around, you have a option to choose something like a windows tablet, a stick pc along with touch screen or a Tv box. not sure on which kind of stuff do the best job unfortunately.
For communication, you need to build the safest/robust assembly point on Internet. The very best option available is XMPP Pidgin chat client.
It's pre-installed in the tails. https://tails.boum.org/doc/anonymous_internet/pidgin/index.en.html As you expected, you can start a group chat. https://superuser.com/questions/1440212/is-there-any-way-to-create-a-group-in-pidgin-like-in-whatsapp
There is couple things you can't do on Tor network or tails Linux.
First, you should read these articles. https://www.hongkiat.com/blog/do-donts-tor-network/amp/ https://tails.boum.org/doc/about/warning/index.en.html https://2019.www.torproject.org/docs/faq.html.en
Since tails is lots more robust than Tor browser bundle on windows, you can ignore the most of issues in Tor browser. Still you have to aware the risk on this.
Not only that, couple of things is getting harder to achieve through Tor.
At first, some website like Twitter, Reddit or YouTube tends to reject to create an account. If that was just a couple of exit nodes, maybe restart the browser might do the trick. https://tor.stackexchange.com/questions/19536/cant-use-reddit-on-tor-what-do-i-do
But if entire exit nodes are rejected by provider, Web based proxy gives you a chance. If that doesn't work, I'd say you should find someone who will to post your messages on viral media.
Secondly, even if you using tails, thats not means you can pay for something anonymously.
If you need to use paid Web base proxy or whatever you want, it's also safer to use anonymous cryptocurrency such as Zcash or monero. not sure how safe are they, pre-installed wallet(Electrum) only supports bitcoin. so you need to use web based wallets.
Or if someone donated a bitcoins to your anonymous wallet, it's safe to use that one through Tor.
submitted by dozenspileofash to HongKong [link] [comments]

A technical dive into CTOR

Over the last several days I've been looking into detail at numerous aspects of the now infamous CTOR change to that is scheduled for the November hard fork. I'd like to offer a concrete overview of what exactly CTOR is, what the code looks like, how well it works, what the algorithms are, and outlook. If anyone finds the change to be mysterious or unclear, then hopefully this will help them out.
This document is placed into public domain.

What is TTOR? CTOR? AOR?

Currently in Bitcoin Cash, there are many possible ways to order the transactions in a block. There is only a partial ordering requirement in that transactions must be ordered causally -- if a transaction spends an output from another transaction in the same block, then the spending transaction must come after. This is known as the Topological Transaction Ordering Rule (TTOR) since it can be mathematically described as a topological ordering of the graph of transactions held inside the block.
The November 2018 hard fork will change to a Canonical Transaction Ordering Rule (CTOR). This CTOR will enforce that for a given set of transactions in a block, there is only one valid order (hence "canonical"). Any future blocks that deviate from this ordering rule will be deemed invalid. The specific canonical ordering that has been chosen for November is a dictionary ordering (lexicographic) based on the transaction ID. You can see an example of it in this testnet block (explorer here, provided this testnet is still alive). Note that the txids are all in dictionary order, except for the coinbase transaction which always comes first. The precise canonical ordering rule can be described as "coinbase first, then ascending lexicographic order based on txid".
(If you want to have your bitcoin node join this testnet, see the instructions here. Hopefully we can get a public faucet and ElectrumX server running soon, so light wallet users can play with the testnet too.)
Another ordering rule that has been suggested is removing restrictions on ordering (except that the coinbase must come first) -- this is known as the Any Ordering Rule (AOR). There are no serious proposals to switch to AOR but it will be important in the discussions below.

Two changes: removing the old order (TTOR->AOR), and installing a new order (AOR->CTOR)

The proposed November upgrade combines two changes in one step:
  1. Removing the old causal rule: now, a spending transaction can come before the output that it spends from the same block.
  2. Adding a new rule that fixes the ordering of all transactions in the block.
In this document I am going to distinguish these two steps (TTOR->AOR, AOR->CTOR) as I believe it helps to clarify the way different components are affected by the change.

Code changes in Bitcoin ABC

In Bitcoin ABC, several thousand lines of code have been changed from version 0.17.1 to version 0.18.1 (the current version at time of writing). The differences can be viewed here, on github. The vast majority of these changes appear to be various refactorings, code style changes, and so on. The relevant bits of code that deal with the November hard fork activation can be found by searching for "MagneticAnomaly"; the variable magneticanomalyactivationtime sets the time at which the new rules will activate.
The main changes relating to transaction ordering are found in the file src/validation.cpp:
There are other changes as well:

Algorithms

Serial block processing (one thread)

One of the most important steps in validating blocks is updating the unspent transaction outputs (UTXO) set. It is during this process that double spends are detected and invalidated.
The standard way to process a block in bitcoin is to loop through transactions one-by-one, removing spent outputs and then adding new outputs. This straightforward approach requires exact topological order and fails otherwise (therefore it automatically verifies TTOR). In pseudocode:
for tx in transactions: remove_utxos(tx.inputs) add_utxos(tx.outputs) 
Note that modern implementations do not apply these changes immediately, rather, the adds/removes are saved into a commit. After validation is completed, the commit is applied to the UTXO database in batch.
By breaking this into two loops, it becomes possible to update the UTXO set in a way that doesn't care about ordering. This is known as the outputs-then-inputs (OTI) algorithm.
for tx in transactions: add_utxos(tx.outputs) for tx in transactions: remove_utxos(tx.inputs) 
Benchmarks by Jonathan Toomim with Bitcoin ABC, and by myself with ElectrumX, show that the performance penalty of OTI's two loops (as opposed to the one loop version) is negligible.

Concurrent block processing

The UTXO updates actually form a significant fraction of the time needed for block processing. It would be helpful if they could be parallelized.
There are some concurrent algorithms for block validation that require quasi-topological order to function correctly. For example, multiple workers could process the standard loop shown above, starting at the beginning. A worker temporarily pauses if the utxo does not exist yet, since it's possible that another worker will soon create that utxo.
There are issues with such order-sensitive concurrent block processing algorithms:
In contrast, the OTI algorithm's loops are fully parallelizable: the worker threads can operate in an independent manner and touch transactions in any order. Until recently, OTI was thought to be unable to verify TTOR, so one reason to remove TTOR was that it would allow changing to parallel OTI. It turns out however that this is not true: Jonathan Toomim has shown that TTOR enforcement is easily added by recording new UTXOs' indices within-block, and then comparing indices during the remove phase.
In any case, it appears to me that any concurrent validation algorithm would need such additional code to verify that TTOR is being exactly respected; thus for concurrent validation TTOR is a hindrance at best.

Advanced parallel techniques

With Bitcoin Cash blocks scaling to large sizes, it may one day be necessary to scale onto advanced server architectures involving sharding. A lot of discussion has been made over this possibility, but really it is too early to start optimizing for sharding. I would note that at this scale, TTOR is not going to be helpful, and CTOR may or may not lead to performance optimizations.

Block propagation (graphene)

A major bottleneck that exists in Bitcoin Cash today is block propagation. During the stress test, it was noticed that the largest blocks (~20 MB) could take minutes to propagate across the network. This is a serious concern since propagation delays mean increased orphan rates, which in turn complicate the economics and incentives of mining.
'Graphene' is a set reconciliation technique using bloom filters and invertible bloom lookup tables. It drastically reduces the amount of bandwidth required to communicate a block. Unfortunately, the core graphene mechanism does not provide ordering information, and so if many orderings are possible then ordering information needs to be appended. For large blocks, this ordering information makes up the majority of the graphene message.
To reduce the size of ordering information while keeping TTOR, miners could optionally decide to order their transactions in a canonical ordering (Gavin's order, for example) and the graphene protocol could be hard coded so that this kind of special order is transmitted in one byte. This would add a significant technical burden on mining software (to create blocks in such a specific unusual order) as well as graphene (which must detect this order, and be able to reconstruct it). It is not clear to me whether it would be possible to efficiently parallelize sorting algortithms that reconstruct these orderings.
The adoption of CTOR gives an easy solution to all this: there is only one ordering, so no extra ordering information needs to be appended. The ordering is recovered with a comparison sort, which parallelizes better than a topological sort. This should simplify the graphene codebase and it removes the need to start considering supporting various optional ordering encodings.

Reversibility and technical debt

Can the change to CTOR be undone at a later time? Yes and no.
For block validators / block explorers that look over historical blocks, the removal of TTOR will permanently rule out usage of the standard serial processing algorithm. This is not really a problem (aside from the one-time annoyance), since OTI appears to be just as efficient in serial, and it parallelizes well.
For anything that deals with new blocks (like graphene, network protocol, block builders for mining, new block validation), it is not a problem to change the ordering at a later date (to AOR / TTOR or back to CTOR again, or something else). These changes would add no long term technical debt, since they only involve new blocks. For past-block validation it can be retroactively declared that old blocks (older than a few months) have no ordering requirement.

Summary and outlook

Taking a broader view, graphene is not the magic bullet for network propagation. Even with the CTOR-improved graphene, we might not see vastly better performance right away. There is also work needed in the network layer to simply move the messages faster between nodes. In the last stress test, we also saw limitations on mempool performance (tx acceptance and relaying). I hope both of these fronts see optimizations before the next stress test, so that a fresh set of bottlenecks can be revealed.
submitted by markblundeberg to btc [link] [comments]

Creating a Segwit (segregated-witness) Bitcoin Wallet Using the Electrum Bitcoin Wallet Version 3 Convert BTC to BCC Using Electrum Wallet and ElectronCash How To Use NODL (DOJO) : Electrum How To Claim BitCoin Cash Sell For Bitcoins Mycelium Electron Cash How To Use NODL ( DOJO) : Setup

Electrum is a lightweight Bitcoin client, based on a client-server protocol. It was released on November 5, 2011. Main features Encrypted wallet: the file that contains bitcoin private keys is […] Kryptowährung Wallet Electrum ist eine Art dünner Wallet - diese Ressource erfordert keinen vollständigen Sprung in die Geschichte der Blockchain, was ein erhebliches Gewicht an Speicher beansprucht. Ein charakteristisches Merkmal von Thin Clients ist gleichzeitig die Speicherung von persönlichen Informationen der Benutzer auf Remote-Servern von Drittanbietern. Electrum is a lightweight Bitcoin client, based on a client-server protocol. Electrum is a type of thin wallets – this resource does not require a complete jump in the history of the blockchain, which takes a significant weight of memory. Electrum wurde im November 2011 veröffentlich und ist ein Bitcoin-Client der auf Einfachheit und Geschwindigkeit getrimmt ist. Bei diesem Client ist es nicht nötig die vollständige Blockchain herunterzuladen. Sofort nach dem Start wird eine Verbindung zu einem von mehreren Servern hergestellt über die die Blockchain benutzt wird. Electrum is a lightweight Bitcoin client, based on a client-server protocol. It was released on november 5, 2011. Main features: Encrypted wallet: the file that contains bitcoin private keys is protected with a password, and never leaves the user's computer.; Deterministic key generation: If you lose your wallet file, you can recover it from its seed.You are protected from your own mistakes.

[index] [612] [33585] [33790] [35067] [45798] [31938] [32008] [50323] [1374] [51475]

Creating a Segwit (segregated-witness) Bitcoin Wallet Using the Electrum Bitcoin Wallet Version 3

Videos informativos y educativos en español sobre la tecnología Bitcoin, blockchains y criptomonedas: resúmenes, entrevistas, tutoriales y más. ¡Suscríbete! In this Electrum tutorial, I walk through how to delete a wallet and restore a native (created with Electrum) Electrum wallet. To Learn more about extending seed phrases with custom words : https ... or from the wiki Bitcoin client graph page I showed you earlier in this video in the Ubuntu software center type Electrum once there click install and the installation will begin for your Bitcoin ... How to sweep private keys - Using the Electrum Bitcoin wallet - Duration: 2:52. Hodl Hodl 9,075 views. 2:52. How To Claim BitCoin Cash Sell For Bitcoins Mycelium Electron Cash - Duration: 17:12. ... The Electrum Bitcoin wallet is software that runs on your computer. It is an application that allows you to send, receive and store bitcoins. It also has advanced features that allow you to check ...

#