A genesis block is the first block of a block chain. Modern versions of Bitcoin number it as block 0, though very early versions counted it as block 1. The genesis block is almost always hardcoded into the software of the applications that utilize its block chain. It is a special case in that it does not reference a previous block, and for Bitcoin and almost all of its derivatives, it produces an unspendable subsidy.| en.bitcoin.it
Reward types & explanation:| en.bitcoin.it
The July 2015 forks were two block chain forks with two or more invalid blocks. They were caused by miners who didn't properly validate blocks before mining on top of them.[1]| en.bitcoin.it
Recently there have been a number of proposals for bitcoin clients which do not store a complete copy of every block in the entire block chain. This page will refer to all such clients as "thin clients". This page is meant to be a place to try to make sense of the security and trust implications of the various schemes.| en.bitcoin.it
Any computer that connects to the Bitcoin network is called a node. Nodes that fully verify all of the rules of Bitcoin are called full nodes. The most popular software implementation of full nodes is called Bitcoin Core, its latest release can be found on the github page.| en.bitcoin.it
Elliptic Curve Digital Signature Algorithm or ECDSA is a cryptographic algorithm used by Bitcoin to ensure that funds can only be spent by their rightful owners. It is dependent on the curve order and hash function used. For bitcoin these are Secp256k1 and SHA256(SHA256()) respectively.| en.bitcoin.it
Bitcoin uses a simple broadcast network to propagate transactions and blocks. All communications are done over TCP. Bitcoin is fully able to use ports other than 8333 via the -port parameter. IPv6 is supported with Bitcoind/Bitcoin-Qt v0.7. Using bitcoin over tor is also supported.| en.bitcoin.it
This page contains sample addresses and/or private keys. Do not send bitcoins to or import any sample keys; you will lose your money.| en.bitcoin.it
Bitcoin currently uses the ECDSA algorithm to generate cryptographic signatures for a given message and secp256k1 keypair. Schnorr is an alternative algorithm with several advantages. One key advantage is that when multiple keys are used to sign the same message with Schnorr, the resulting signatures can be combined into a single signature. This can be used to significantly reduce the size of multisig payments and other multisig related transactions, for example lightning channel transactions.| en.bitcoin.it
Note: This page is seriously outdated and largely unmaintained; due to past incidents of edit-warring it has not been subject to much peer review.| en.bitcoin.it
Bitcoin uses a scripting system for transactions. Forth-like, Script is simple, stack-based, and processed from left to right. It is intentionally not Turing-complete, with no loops.| en.bitcoin.it
Byte-map of Transaction with each type of TxIn and TxOutA transaction is a transfer of Bitcoin value that is broadcast to the network and collected into blocks. A transaction typically references previous transaction outputs as new transaction inputs and dedicates all input Bitcoin values to new outputs. Transactions are not encrypted, so it is possible to browse and view every transaction ever collected into a block. Once transactions are buried under enough confirmations they can be conside...| en.bitcoin.it
This page describes a BIP (Bitcoin Improvement Proposal).| en.bitcoin.it
A distributed contract is a method of using Bitcoin to form agreements with people via the block chain. Contracts don't make anything possible that was previously impossible, but rather, they allow you to solve common problems in a way that minimizes trust. Minimal trust often makes things more convenient by allowing human judgements to be taken out of the loop, thus allowing complete automation.| en.bitcoin.it
Blocks in the main chain (black) are the longest series of blocks that go from the genesis block (green) to the current block. Purple blocks are blocks that are not in the longest chain and therefore not used.A block chain is a transaction database shared by all nodes participating in a system based on the Bitcoin protocol. A full copy of a currency's block chain contains every transaction ever executed in the currency. With this information, one can find out how much value belonged to each...| en.bitcoin.it
Transaction data is permanently recorded in files called blocks. They can be thought of as the individual pages of a city recorder's recordbook (where changes to title to real estate are recorded) or a stock transaction ledger. Blocks are organized into a linear sequence over time (also known as the block chain). New transactions are constantly being processed by miners into new blocks which are added to the end of the chain. As blocks are buried deeper and deeper into the blockchain they bec...| en.bitcoin.it
Conversion from ECDSA public key to Bitcoin AddressThis article may be too technical for some users. The more basic article on Bitcoin Addresses may be more appropriate.| en.bitcoin.it
A proof of work is a piece of data which is difficult (costly, time-consuming) to produce but easy for others to verify and which satisfies certain requirements. Producing a proof of work can be a random process with low probability so that a lot of trial and error is required on average before a valid proof of work is generated. Bitcoin uses the Hashcash proof of work system.| en.bitcoin.it
Signet (BIP 0325) is a new test network for Bitcoin which adds an additional signature requirement to block validation. Signet is similar in nature to testnet, but more reliable and centrally controlled. There is a default signet network ("Signet Global Test Net VI" as of this writing), but anyone can run their own signet network at their whim.| en.bitcoin.it
Blockchain-based currencies use encoded strings, which are in a Base58Check encoding with the exception of Bech32 encodings. The encoding includes a prefix (traditionally a single version byte), which affects the leading symbol(s) in the encoded result. The following is a list of some prefixes which are in use in the reference Bitcoin codebase.[1][2][3]| en.bitcoin.it
A fixed money supply, or a supply altered only in accord with objective and calculable criteria, is a necessary condition to a meaningful just price of money.[1]| en.bitcoin.it
This article describes the operation of OP_CHECKSIG in non-segwit scripts. The hash digest for OP_CHECKSIG, OP_CHECKSIGVERIFY, OP_CHECKMULTISIG, OP_CHECKMULTISIGVERIFY in segwit scripts is calculated differently, as described in BIP 143.| en.bitcoin.it
This page is a discussion of the different ways of storing bitcoins, whether for investment purposes or as a medium of exchange.| en.bitcoin.it
On August 15 2010, it was discovered that block 74638 contained a transaction that created 184,467,440,737.09551616 bitcoins for three different addresses.[1][2][3]| en.bitcoin.it
See also: Scalability FAQ| en.bitcoin.it
A modified Base 58 binary-to-text encoding known as Base58Check is used for encoding Bitcoin addresses.| en.bitcoin.it
This page contains sample addresses and/or private keys. Do not send bitcoins to or import any sample keys; you will lose your money.| en.bitcoin.it
This is a graph of secp256k1's elliptic curve y2 = x3 + 7 over the real numbers. Note that because secp256k1 is actually defined over the field Zp, its graph will in reality look like random scattered points, not anything like this.secp256k1 refers to the parameters of the elliptic curve used in Bitcoin's public-key cryptography, and is defined in Standards for Efficient Cryptography (SEC) (Certicom Research, http://www.secg.org/sec2-v2.pdf). Currently Bitcoin uses secp256k1 with the ECDSA al...| en.bitcoin.it
Bitcoin is P2P electronic cash that is valuable over legacy systems because of the monetary autonomy it brings to its users. Bitcoin seeks to address the root problem with conventional currency: all the trust that's required to make it work -- Not that justified trust is a bad thing, but trust makes systems brittle, opaque, and costly to operate. Trust failures result in systemic collapses, trust curation creates inequality and monopoly lock-in, and naturally arising trust choke-points can be...| en.bitcoin.it