Bitcoind transaction data verification

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I run a 0-confirmation tool. To track new transactions I use:

bitcoind getrawmempool new transactions in new block not available in mempool (it seems I do not receive all transactions in mempool before my client accepts a new block)

I trust my bitcoin client transaction verification process (protocol rules). (I expect it to do all the steps in: https://en.bitcoin.it/wiki/Protocol_rules#.22tx.22_messages)

I expect I do not have the guarantee the client/person who created the new block has followed the protocol rules for the included transactions, so I want to check the 'missing' transaction from my mempool.

I know 6 confirmations is expected to be 'safe', but I would like to do a 0-confirmation (or 1-confirmation concerning a new block) as safe as possible.

1: Is every transaction checked by my bitcoind client before accepting a new block (local)? (to be sure every transaction available in mempool and blockchain of my (official) client meet the protocol...

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Bitcoind only scrapes the blockchain for a few transaction types: Pay-to-pubkey, pay-to-pubkey-hash, and pay-to-script-hash. If you check https://en.bitcoin.it/wiki/Script you'll see many more script operators that can be used, so the protocol isn't just those three script types.

Since the scripts have a very definite form, your client will look for the cases where the payments are to address YOU own instead of others.

OP_DUP OP_HASH160 OP_EQUALVERIFY OP_CHECKSIG

If bitcoins were sent to this script but with other script operations at the end, your node wouldn't report them as spendable.

Verifying this yourself is easy if you already have a working and completely correct script interpreter. You could look for non-standard outputs, since they do get mined on occasion.

However, reproducing bitcoind's script interpreter, with bug-for-bug compatibility is tricky. Certain clients have been forked from the blockchain by not following every quirk in the...

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How Microsoft & Tierion are Working to Process Data on Bitcoin Blockchain

Tierion, which has been collaborating with the $547 billion technology giant Microsoft since February of 2017, has finally launched its data verification platform which processes massive amounts of information using the secure and immutable bitcoin blockchain.

In February, Microsoft Azure, the cloud services provider of Microsoft, revealed in a statement that in partnership with Tierion, it has been attempting to create platforms on top of the bitcoin blockchain to secure information more efficiently.

“Public blockchains such as Bitcoin are exceptionally secure, but slow. The current throughput of the Bitcoin network is about four transactions per second. Tierion solves this scalability problem by cryptographically linking millions of data points to a single transaction,” Cale Teeter of Microsoft wrote in an official blog post.

In the past, experts including blockchain,...

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Whether you’re interested in becoming a developer for blockchain applications, or you’re just looking to understand what happens under the hood when you send bitcoin to a friend, it’s good to have a working knowledge of what happens when you create and broadcast Bitcoin transactions to the Bitcoin network. Why?

Because transactions are a basic entity on top of which the bitcoin blockchain is constructed. Transactions are the result of a brilliant collision of cryptography, data structures, and simple non-turing-complete scripting. They’re simple enough that common transaction types aren’t overly-complex, but flexible enough to allow developers to encode fairly customized transactions types as well. Today we’ll take a tour of the former.

As a developer, how does your bitcoin client post a new transaction to the network (and what happens when it’s received)?

What exactly is happening when you send some bitcoin to a friend?

This post will assume that the...

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Is it possible to cancel a Bitcoin transaction ...

... which was not yet broadcasted?

Yes, obviously it is possible. I'd propose you choose this method in your Bitcoin app by showing the user a confirmation screen for some seconds with information about the transaction and some buttons saying cancel and confirm. @nahtnam proposed a 60 minute delay which is too much, considering you may loose internet access or want the transaction to appear in the block chain as soon as possible.

... which was already broadcasted?

No, very unlikely. To cancel such a transaction, you'd need to create a block yourself which moves the inputs of the original transaction to one of your own addresses. (Effectively invalidating the original transaction.) However, creating a block costs several thousand dollars as of now and finding a block is not guaranteed.

Another possibility would be to broadcast another transaction taking the same inputs as the original one and...

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Verify transactions and other scripts

Enter the raw transaction, redeem script, pubkey, hd address or wif key to convert it into a readable format that can be verified manually.


Redeem Script

The above redeem script has been decoded

Transaction Script

The above script has been decoded

Version:

Transaction Size:

Lock time:

WIF key

The above wif key has been decoded

Address:

Public key:

Private key:

Is compressed:

Public key

The above public key has been encoded to its address

Address:

Unable to decode


Sign Transaction once a transaction has been verified

Once you have verified a transaction you can sign and then broadcast it into the network.



Advanced Options

There is a problem with one or more of your inputs, please check and try again

The above transaction has been...

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Block

Blocks are found in the Bitcoin block chain. Blocks connect all transactions together. Transactions are combined into single blocks and are verified every ten minutes through mining. Each subsequent block strengthens the verification of the previous blocks, making it impossible to double spend bitcoin transactions (see double spend below).

BIP

Bitcoin Improvement Proposal or BIP, is a technical design document providing information to the bitcoin community, or describing a new feature for bitcoin or its processes or environment which affect the Bitcoin protocol. New features, suggestions, and design changes to the protocol should be submitted as a BIP. The BIP author is responsible for building consensus within the community and documenting dissenting opinions.

Block Chain

The Bitcoin block chain is a public record of all Bitcoin transactions. You might also hear the term used as a “public ledger.” The block chain shows every single record...

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I agree with the general idea, and think this could be pretty useful.

While "decoderawtransaction" can be used to check the structure of transactions, and in a hacky way "signrawtransaction" can be used to verify scripts and signatures, it's feels more like an incomplete workaround.

A few random use cases that come to my mind, more or less related to this topic:

User doesn't want to run a node (for whatever reason), and instead uses a third party API provider; Bitcoin Core could be used to double check the results, at least to some degree User wants to know which inputs are signed in a partially signed transaction User signs a raw transaction offline, and wants to verify the signatures on another machine, before moving the signing keys on paper back to a vault User receives a time-locked refund transaction, say for example from greenaddress.it, and wants to ensure the refund transaction is valid Someone fools blockchain.info' pushtx API and "spoofs" a transaction,...
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There are two variations of the original bitcoin program available; one with a graphical user interface (usually referred to as just “Bitcoin”), and a 'headless' version (called bitcoind). They are completely compatible with each other, and take the same command-line arguments, read the same configuration file, and read and write the same data files. You can run one copy of either Bitcoin or bitcoind on your system at a time (if you accidently try to launch another, the copy will let you know that Bitcoin or bitcoind is already running and will exit).

Linux Quickstart

The simplest way to start from scratch with the command line client, automatically syncing blockchain and creating a wallet, is to just run this command (without arguments) from the directory containing your bitcoind binary:

./bitcoind

To run with the standard GUI interface:

./bitcoin-qt

Command-line arguments

Give bitcoind the -? or –-help argument and it will print out a list of...

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Temporary transaction issues (Bitcoind migration) | Localbitcoins

zillodillo

Hi! LocalBitcoins team is moving bitcoind to a new server. This may cause issues with the incoming and outgoing transactions. The issues should be over shortly and we apologize for the inconvenience this may cause.

quickcoin

Thank you for the update LBC team ;)

5flags

Thanks guys. I've disabled my ads to avoid any confusion, please post again when you're on a green light :) Happy Monday!

voxavion

thanks for quick update

Austra

Ah, no wonder I'm scratching my head looking at 13 confirmations on blockchain but the LBC wallet is not showing the amount. :)

rhysking101

Would this be why i sent some btc to another account at 7:30 and it still has not arrived even unconfirmed?

5flags

@rhysking101 I think that would fall under "incoming and outgoing transactions"...

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Hello.
I use Ubuntu 16.04.2 LTS (Xenial Xerus).
I already installed the Bitcoind Server via the PPA-Bitcoin.

But my problem is that it fails to connect the PHP JSON-RPC API via 127.0.0.1:8332.

So I would like to know how to start the Bitcoind Daemon after following the instructions given on: https://hub.docker.com/r/kylemanna/bitcoind/???

Is it necessary to first remove the Bitcoind Server installed via Ubuntu PPA / Bitcoin before following the instructions of the link: https://hub.docker.com/r/kylemanna/bitcoind/ ???

And how to start the Bitcoind Daemon after following the instructions given on: https://hub.docker.com/r/kylemanna/bitcoind/ ???

Thank you in...

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...
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BitGoD is a NodeJS package and binary which operates a bitcoind-compatible JSON-RPC API. It is designed to proxy non-wallet API calls to a local bitcoind instance, though this is not required, if those API calls are not used. For wallet-related API calls, BitGoD speaks on the back-end to the BitGo REST API, and allows the client to easily operate a multi-sig wallet as if it were dealing with a standard bitcoind instance.

NodeJS must be installed as a prerequisite.

$ npm install -g bitgod

Running bitgod -h will produce usage information.

$ bitgod -h

usage: bitgod [-h] [-v] [-conf CONF] [-env ENV] [-rpcbind RPCBIND]

[-rpcport RPCPORT] [-rpcuser RPCUSER] [-rpcpassword RPCPASSWORD]

[-rpcssl] [-rpcsslkey RPCSSLKEY] [-rpcsslcert RPCSSLCERT]

[-proxyhost PROXYHOST] [-proxyport PROXYPORT]

[-proxyuser PROXYUSER] [-proxypassword PROXYPASSWORD]

[-proxyrpcssl]...

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Once you've sent a bitcoin payment from CoinJar to an external bitcoin address, that transfer's details (amount sent, sending/receiving bitcoin address, as well as the date of transfer) can be found on the blockchain. This information is then publicly available, and given its own transaction ID - or TXID.

At times, the recipient of your bitcoin transfer may request this transaction ID from you - typically to confirm you've sent the payment successfully. This transaction ID is safe to share - no personal information is sent from your CoinJar to the blockchain.

Finding a transaction ID

Visit https://blockchain.info/ in a new browser window. This is a public blockchain explorer, which can be used to view all previous bitcoin payments made on the blockchain. There are alternatives sites that can also search the blockchain, and it's up to personal preference which one you use. In the 'Search' area, you'll need to enter information that is specific to your bitcoin...
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In this overview, you’ll learn how the Bitcoin system works in general and what terminology we use to describe each part. This is recommended reading for anyone who is new to Bitcoin development. If you’ve been around for awhile, you can probably just skim it or skip it altogether.

In addition to this overview, we highly recommend reading Satoshi Nakamoto’s original high-level description of the Bitcoin system, published in 2008.

21

We’ll refer often to 21, which is designed to provide everything you need to follow the tutorials on 21.co, including a technology that lets you receive a steady stream of satoshis (fractional bitcoins) for use in creating actual transactions that will appear on the blockchain.

Hashes

One of the most frequently used data types in Bitcoin is a cryptographic hash. (We’ll simply call them “hashes” from this point on, but you should be aware that there are non-cryptographic hashes that don’t have the same...

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Bitcoin is a global form of digital currency. Unlike traditional currencies, which were frequently backed by gold and silver, bitcoin is based on distributed computing. While traditional currencies are printed by central banks, bitcoins are created or “mined” by distributed computer networks.

Another way bitcoin differs from traditional currencies is that it is decentralised, meaning that it is not controlled by any single institution. As a result, miners around the world create new units of the currency and confirm its transactions.

FXCM does not endorse bitcoin and does not offer bitcoin trading at the present time.

Bitcoin / USD Chart

How does Bitcoin work?

The bitcoin network comprises thousands of computers linked together through a ledger of all bitcoin transactions known as the “block chain” and governed by a uniform bitcoin protocol. Every bitcoin transaction produces a series of letters and numbers, known as a hash, which miners then...

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Transactions are the most important part of the bitcoin system. Everything else in bitcoin is designed to ensure that transactions can be created, propagated on the network, validated, and finally added to the global ledger of transactions (the blockchain). Transactions are data structures that encode the transfer of value between participants in the bitcoin system. Each transaction is a public entry in bitcoin’s blockchain, the global double-entry bookkeeping ledger.

In this chapter we will examine all the various forms of transactions, what they contain, how to create them, how they are verified, and how they become part of the permanent record of all transactions.

A transaction’s lifecycle starts with the transaction’s creation, also known as origination. The transaction is then signed with one or more signatures indicating the authorization to spend the funds referenced by the transaction. The transaction is then broadcast on the bitcoin network, where each...

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Last updated: 20th March 2015

Bitcoin transactions are sent from and to electronic bitcoin wallets, and are digitally signed for security. Everyone on the network knows about a transaction, and the history of a transaction can be traced back to the point where the bitcoins were produced.

Holding onto bitcoins is great if you’re a speculator waiting for the price to go up, but the whole point of this currency is to spend it, right? So, when spending bitcoins, how do transactions work?

There are no bitcoins, only records of bitcoin transactions

Here’s the funny thing about bitcoins: they don’t exist anywhere, even on a hard drive. We talk about someone having bitcoins, but when you look at a particular bitcoin address, there are no digital bitcoins held in it, in the same way that you might hold pounds or dollars in a bank account. You cannot point to a physical object, or even a digital file, and say “this is a bitcoin”.

Instead, there are only...

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