Bitcoin Wiki - User contributions [en]

Transaction

2021-03-14T06:45:03Z

Diegorodriguezv: an transaction -> a transaction (see https://www.grammar.com/a-vs-an-when-to-use/)

[[File:TxBinaryMap.png|thumb|right|Byte-map of Transaction with each type of TxIn and TxOut]]
A '''transaction''' is a transfer of Bitcoin value that is broadcast to the [[network]] and collected into [[block|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 [[Confirmation|confirmations]] they can be considered [[Irreversible Transactions|irreversible]].

This article is about '''on-chain transactions'''. See also: [[Off-Chain Transactions]]

Standard transaction outputs nominate [[address|addresses]], and the redemption of any future inputs requires a relevant signature.

All transactions are visible in the [[block chain]], and can be viewed with a hex editor. A [[block chain browser]] is a site where every transaction included within the block chain can be viewed in human-readable terms. This is useful for seeing the technical details of transactions in action and for verifying payments.

=== General format of a Bitcoin transaction (inside a block) ===
{| class="wikitable"
|-
! Field
! Description
! Size
|-
|Version no
|currently 1
|4 bytes
|-
|Flag
|If present, always 0001, and indicates the presence of witness data
|optional 2 byte array
|-
|In-counter
| positive integer [[ Protocol_specification#Variable_length_integer|VI = VarInt]]
| 1 - 9 bytes
|-
|list of inputs
|[[Transaction#General_format_.28inside_a_block.29_of_each_input_of_a_transaction_-_Txin|the first input of the first transaction is also called "coinbase" (its content was ignored in earlier versions)]]
|<in-counter>-many inputs
|-
|Out-counter
| positive integer [[ Protocol_specification#Variable_length_integer|VI = VarInt]]
| 1 - 9 bytes
|-
|list of outputs
|[[Transaction#General_format_.28inside_a_block.29_of_each_output_of_a_transaction_-_Txout|the outputs of the first transaction spend the mined bitcoins for the block]]
|<out-counter>-many outputs
|-
|Witnesses
|A list of witnesses, 1 for each input, omitted if flag above is missing
|variable, see [[Segregated_Witness]]
|-
|lock_time
|if non-zero and sequence numbers are < 0xFFFFFFFF: block height or timestamp when transaction is final
|4 bytes
|}

=== Principle example of a Bitcoin transaction with 1 input and 1 output only ===

==== Data ====

<pre>Input:
Previous tx: f5d8ee39a430901c91a5917b9f2dc19d6d1a0e9cea205b009ca73dd04470b9a6
Index: 0
scriptSig: 304502206e21798a42fae0e854281abd38bacd1aeed3ee3738d9e1446618c4571d10
90db022100e2ac980643b0b82c0e88ffdfec6b64e3e6ba35e7ba5fdd7d5d6cc8d25c6b241501

Output:
Value: 5000000000
scriptPubKey: OP_DUP OP_HASH160 404371705fa9bd789a2fcd52d2c580b65d35549d
OP_EQUALVERIFY OP_CHECKSIG</pre>

==== Explanation ====

The input in this transaction imports 50 BTC from output #0 in transaction f5d8... Then the output sends 50 BTC to a Bitcoin address (expressed here in hexadecimal 4043... instead of the normal base58). When the recipient wants to spend this money, he will reference output #0 of this transaction in an input of his own transaction.

===== Input =====

An '''input''' is a reference to an output from a previous transaction. Multiple inputs are often listed in a transaction. All of the new transaction's input values (that is, the total coin value of the previous outputs referenced by the new transaction's inputs) are added up, and the total (less any transaction fee) is completely used by the outputs of the new transaction. '''Previous tx''' is a [[hash]] of a previous transaction. '''Index''' is the specific output in the referenced transaction. '''ScriptSig''' is the first half of a [[script]] (discussed in more detail later).

The script contains two components, a signature and a public key. The public key must match the hash given in the script of the redeemed output. The public key is used to verify the redeemers signature, which is the second component. More precisely, the second component is an [[ECDSA]] signature over a hash of a simplified version of the transaction. It, combined with the public key, proves the transaction was created by the real owner of the bitcoins in question. Various flags define how the transaction is simplified and can be used to create different types of payment.

===== Output =====

An '''output''' contains instructions for sending bitcoins. '''Value''' is the number of Satoshi (1 BTC = 100,000,000 Satoshi) that this output will be worth when claimed. '''ScriptPubKey''' is the second half of a script (discussed later). There can be more than one output, and they share the combined value of the inputs. Because each output from one transaction can only ever be referenced once by an input of a subsequent transaction, the entire combined input value needs to be sent in an output if you don't want to lose it. If the input is worth 50 BTC but you only want to send 25 BTC, Bitcoin will create two outputs worth 25 BTC: one to the destination, and one back to you (known as "[[change]]", though you send it to yourself). Any input bitcoins not redeemed in an output is considered a [[transaction fee]]; whoever generates the block can claim it by inserting it into the coinbase transaction of that block.
[[File:transaction.png|thumb|A sends 100 BTC to C and C generates 50 BTC. C sends 101 BTC to D, and he needs to send himself some change. D sends the 101 BTC to someone else, but they haven't redeemed it yet. Only D's output and C's change are capable of being spent in the current state.]]

===== Verification =====

To verify that inputs are authorized to collect the values of referenced outputs, Bitcoin uses a custom Forth-like [[script|scripting]] system. The input's scriptSig and the ''referenced'' output's scriptPubKey are evaluated (in that order), with scriptPubKey using the values left on the stack by scriptSig. The input is authorized if scriptPubKey returns true. Through the scripting system, the sender can create very complex conditions that people have to meet in order to claim the output's value. For example, it's possible to create an output that can be claimed by anyone without any authorization. It's also possible to require that an input be signed by ten different keys, or be redeemable with a password instead of a key.

=== Types of Transaction ===
Bitcoin currently creates two different scriptSig/scriptPubKey pairs. These are described below.

It is possible to design more complex types of transactions, and link them together into cryptographically enforced agreements. These are known as [[Contracts]].

==== Pay-to-PubkeyHash ====

scriptPubKey: OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
scriptSig: <sig> <pubKey>
A Bitcoin [[address]] is only a hash, so the sender can't provide a full public key in scriptPubKey. When redeeming coins that have been sent to a Bitcoin address, the recipient provides both the signature and the public key. The script verifies that the provided public key does hash to the hash in scriptPubKey, and then it also checks the signature against the public key.

Checking process:
{| class="wikitable"
|-
! Stack
! Script
! Description
|-
|Empty.
| <sig> <pubKey> OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
| scriptSig and scriptPubKey are combined.
|-
|<sig> <pubKey>
| OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
| Constants are added to the stack.
|-
|<sig> <pubKey> <pubKey>
| OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
| Top stack item is duplicated.
|-
|<sig> <pubKey> <pubHashA>
|<pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG
| Top stack item is hashed.
|-
|<sig> <pubKey> <pubHashA> <pubKeyHash>
|OP_EQUALVERIFY OP_CHECKSIG
| Constant added.
|-
|<sig> <pubKey>
|OP_CHECKSIG
| Equality is checked between the top two stack items.
|-
|true
|Empty.
|Signature is checked for top two stack items.
|}

==== Pay-to-Script-Hash ====

scriptPubKey: OP_HASH160 <scriptHash> OP_EQUAL
scriptSig: ..signatures... <serialized script>

m-of-n multi-signature transaction:
scriptSig: 0 <sig1> ... <script>
script: OP_m <pubKey1> ... OP_n OP_CHECKMULTISIG

P2SH addresses were created with the motivation of moving "the responsibility for supplying the conditions to redeem a transaction from the sender of the funds to the redeemer. They allow the sender to fund an arbitrary transaction, no matter how complicated, using a 20-byte hash"[https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki#motivation 1]. Pay-to-Pubkey-hash addresses are similarly a 20-byte hash of the public key.

Pay-to-script-hash provides a means for complicated transactions, unlike the Pay-to-pubkey-hash, which has a specific definition for scriptPubKey, and scriptSig. The specification places no limitations on the script, and hence absolutely any contract can be funded using these addresses.

The scriptPubKey in the funding transaction is script which ensures that the script supplied in the redeeming transaction hashes to the script used to create the address.

In the scriptSig above, 'signatures' refers to any script which is sufficient to satisfy the following serialized script.

Checking process:
{| class="wikitable"
|-
! Stack
! Script
! Description
|-
|Empty.
| 0 <sig1> <sig2> OP_2 <pubKey1> <pubKey2> <pubKey3> OP_3 OP_CHECKMULTISIG
| Only the scriptSig is used.
|-
| 0 <sig1> <sig2> OP_2 <pubKey1> <pubKey2> <pubKey3> OP_3
| OP_CHECKMULTISIG
| Constants are added to the stack.
|-
| true
| Empty
| Signatures validated in the order of the keys in the script.
|}

See also [[BIP 0016]]

=== Generation ===

Generations have a single input, and this input has a "[[Coinbase |coinbase]]" parameter instead of a scriptSig. The data in "coinbase" can be anything; it isn't used. Bitcoin puts the current compact-format [[target]] and the arbitrary-precision "extraNonce" number there, which increments every time the Nonce field in the [[block_hashing_algorithm|block header]] overflows. Outputs can be anything, but Bitcoin creates one exactly like an IP address transaction.
The extranonce contributes to enlarge the domain for the proof of work function. Miners can easily modify nonce (4byte), timestamp and extranonce (2 to 100bytes).

=== General format (inside a block) of each input of a transaction - Txin ===
{| class="wikitable"
|-
! Field
! Description
! Size
|-
|Previous Transaction hash
| doubled [[Wikipedia:SHA-256|SHA256]]-[[hash|hashed]] of a (previous) to-be-used transaction
|32 bytes
|-
|Previous Txout-index
| non negative integer indexing an output of the to-be-used transaction
|4 bytes
|-
|Txin-script length
|non negative integer [[ Protocol_specification#Variable_length_integer|VI = VarInt]]
|1 - 9 bytes
|-
|Txin-script / scriptSig
|[[Script]]
|<in-script length>-many bytes
|-
|sequence_no
|normally 0xFFFFFFFF; irrelevant unless transaction's lock_time is > 0
|4 bytes
|}

The input sufficiently describes where and how to get the bitcoin amout to be redeemed.
If it is the (only) input of the first transaction of a block, it is called the generation transaction input and its content completely ignored. (Historically the Previous Transaction hash is 0 and the Previous Txout-index is -1.)

=== General format (inside a block) of each output of a transaction - Txout ===
{| class="wikitable"
|-
! Field
! Description
! Size
|-
|value
|non negative integer giving the number of [[FAQ#What_do_I_call_the_various_denominations_of_bitcoins.3F|Satoshis(BTC/10^8)]] to be transfered
|8 bytes
|-
|Txout-script length
|non negative integer
|1 - 9 bytes [[ Protocol_specification#Variable_length_integer|VI = VarInt]]
|-
|Txout-script / scriptPubKey
|[[Script]]
|<out-script length>-many bytes
|}
The output sets the conditions to release this bitcoin amount later. The sum of the output values of the first transaction is the value of the mined bitcoins for the block plus possible transactions fees of the other transactions in the block.

==See Also==

* [[Script]]
* [[Protocol rules#"tx" messages|Protocol rules - "tx" messages]]
* [[Protocol documentation#Transaction Verification|Protocol documentation - Transaction Verification]]
* [[Raw Transactions]]
* [[Coin analogy]]
* [[Transaction Malleability]]
* [[Transaction broadcasting]]

[[Category:Technical]]
[[Category:Vocabulary]]
[[de:Transaktion]]
[[es:Transacción]]
[[pl:Transakcje]]

Satoshi (unit)

2021-03-14T06:28:10Z

Diegorodriguezv: /* Symbol */ Copied the symbol over from https://en.wikipedia.org/wiki/Approximation#Unicode

[[File:SatoshiUsage.png|thumb|The term "satoshi" in use on a message board]]The '''satoshi''' is currently the smallest unit of the bitcoin currency recorded on the [[block chain]].<ref name="se">[http://bitcoin.stackexchange.com/questions/114/what-is-a-satoshi What is a 'Satoshi'? - Bitcoin Stack Exchange]</ref> It is a one hundred millionth of a single bitcoin (0.00000001 BTC).<ref name="se"/> The unit has been named in collective homage to the original creator of Bitcoin, [[Satoshi Nakamoto]].<ref name="ribuck"/>

All amounts in the block chain are denominated in satoshi before being converted for display.<ref name="why">{{cite btct|title=Why 1BTC should equal 10^8 satoshi ?|date=11 October 2014|id=819656}}</ref> The source code also uses satoshi when specifying an amount of bitcoin.<ref name="nov08"/> When displaying an extremely fine fraction of a bitcoin, such as when calculating [[satoshi per byte|fee per byte]] or a [[Bitcoin faucet|faucet]] reward, the amount is displayed in satoshi for readability.<ref>{{cite web|title=How do I calculate my transaction fee?|work=[[21]] Support|author=Binns, Will|date=|accessdate=23 October 2017|url=https://support.21.co/bitcoin/transactions-and-fees/how-do-i-calculate-my-transaction-fee}}</ref><ref>{{cite web|title=Do These "Free Bitcoin" Sites Work?|work=[[CryptoCoinsNews]]|author=Barnes, Samuel|date=9 April 2014|accessdate=19 August 2015|url=https://www.cryptocoinsnews.com/do-free-bitcoin-sites-work/}}</ref>

Although the satoshi is the finest amount that can be recorded in the block chain,<ref name="why"/> [[payment channels]] may need to make very granular payments and so are sometimes denominated in ''millisatoshi'', which are one hundred billionths of a single bitcoin.<ref>[https://github.com/ElementsProject/lightning/blob/master/README.md#receiving-and-receiving-payments Receiving and receiving payments]</ref>

In January 2018, 1 Euro cent is worth approximately 83 satoshi.

==History==
The value of a bitcoin in satoshi was decided by Satoshi Nakamoto to be 100 million no later than November 2008.<ref name="nov08">{{cite btct|id=382374|date=23 December 2013|title=Bitcoin source from November 2008.}}</ref>

On November 15, 2010, ribuck proposed that the one hundredth of a bitcoin (0.01 BTC) be called a ''Satoshi''.<ref>{{cite btct|id=369|post=22160|date=14 July 2010|title=Official Bitcoin Unicode Character?}}</ref> Four months later he instead suggested that the one hundred millionth unit be called an ''austrian'' or a ''satoshi''.<ref>{{cite btct|id=3311|post=46648|date=10 February 2011|title=More divisibility required - move the decimal point}}</ref> The name ''satoshi'' caught on, and was widely adopted thereafter.<ref name="ribuck">{{cite btct|id=407442|post=4415850|date=9 January 2014|title=How did “satoshi” become the name of the base unit?}}</ref>

In December 2017, BIP-176<ref>https://github.com/bitcoin/bips/blob/master/bip-0176.mediawiki</ref> also proposed "Bits" be used as a standard term for 100 (one hundred) satoshis or 1/1,000,000 (one one-millionth) of a bitcoin.

==Usage==
===Plural===
Traditionally, the plural form has been simply ''satoshi'',<ref>[https://en.bitcoin.it/w/index.php?title=Help:FAQ&diff=53369&oldid=53362 Bitcoin Wiki revision by theymos]</ref> but the term ''satoshis'' is also popular and equally correct. If the plural form were to follow the rules of Japanese grammar, it may be pronounced as ''satoshisa'',<ref name="jj73">{{cite btct|id=289475|post=3112861|date=9 September 2013|title=satoshii}}</ref> or simply ''satoshi''.<ref name="jj73"/>

===Symbol===
Satoshi is often abbreviated to ''sat'' or ''s'', although no currency symbol has been widely adopted. There are various proposed symbols:

{| class="wikitable"
|-
! Symbol
! Explanation
|-
| [[File:Satoshi-symbol-small.png|frameless|left]]
| Reminiscent of the Japanese aesthetic, the closest character being 丰 meaning: "Bountiful - abundant, lush, bountiful, plenty, luxurious growth of grass" which suggests vasts amount of Satoshi are still left to mine. In Unicode the closest character would be (U+2250) ≐, a mathematical symbol meaning "Approaching the limit" suggesting the finite supply, always approaching the limit when 21 million Bitcoins are mined. There is also a play on the phrase ''Stack Sats'' as represented by the 3 stacked horizontal bars. This symbol was adopted by the [https://satoshicap.net/ Satoshi Cap] exchange on Feb. 22, 2021. Learn more at http://satsymbol.com.
|-
| 里
| In Japanese names, this character can (rarely) be read "satoshi". It is an uncommon Chinese/Japanese character on its own, and an infrequent radical (kangxi #166). It can be seen as a radical in the common kanji 理 and 量, used in meaningful words like: 理想 (ideals), 理論 (theory), 理性 (reason), 理科 (science), and 量 (quantity). "Satoshi" is a rare reading; more commonly it is read as "ri" or "sato".
|-
| シ
| A Japanese katakana representing the syllable "shi". Note that this character is extremely common in Japanese, so it could cause confusion. Also, it can mean "death" in Japanese and Chinese.
|-
| ㋛
| As above, but circled to distinguish it from the katakana.
|-
| し
| As above, but this is the hiragana instead of the katakana. This is even more common than シ in Japanese writing, however.
|-
| サ
| A Japanese katakana representing the syllable "sa". Maybe it looks more reminiscent of a currency symbol than others. Note that this character is extremely common in Japanese, so it could cause confusion.
|}

==References==
<references/>
__NOTOC__
{{article}}
[[Category:Denominations]]
[[Category:Terms and properties named after Satoshi Nakamoto]]

Segregated Witness

2021-03-14T06:16:22Z

Diegorodriguezv: /* History and Activation */ Changed the link to archived version because the original was deleted

{{infobox |title=SegWit|image=<hr style="background-color: #f9f9f9;"/>[[File:Segwit.png|256px]]<hr style="background-color: #f9f9f9;"/>
|fulltitle=Segregated Witness (Consensus layer)
|bipnumber=[[BIP_0141|BIP 141]]
|purpose=Prevent unintended [[transaction malleability]]
|bit=Bit 1 "segwit"
|starttime=2016-11-15 00:00:00
|timeout=2017-11-15 00:00:00
|supermajority=95% of last 2016 block period
|lockin=Block #479708 2017-08-08 19:05:58
|activated=Block #481824 2017-08-24 01:57:37
}}'''Segregated Witness''' (abbreviated as '''SegWit''') is an implemented protocol upgrade intended to provide protection from [[transaction malleability]] and [[Block size limit controversy|increase block capacity]]. SegWit separates the ''witness'' from the list of inputs. The witness contains data required to check transaction validity but is not required to determine transaction effects.
Additionally, a new ''weight'' parameter is defined, and blocks are allowed to have at most 4 million [[weight units]] (WU). Non-witness and pre-segwit witness bytes weigh 4 WU, but each byte of Segwit witness data only weighs 1 WU, allowing blocks that are larger than 1 MB without a hardforking change.

After the successful activations of OP_CLTV and OP_CSV, SegWit was the last protocol change needed to make the [[Lightning Network]] safe to deploy on the Bitcoin network.

Because the new witness field contains [[Script]] versioning, it is also possible to make changes to or introduce new opcodes to SegWit scripts that would have originally required additional complexity to function without SegWit.

=== History and Activation ===

During 2016 and 2017 activation of segregated witness was blocked by miners for political reasons by exploiting a flaw in the [[BIP 9]] activation mechanism.
On a technical level, the consensus rules of bitcoin are controlled by the [[economic majority]] not the [[Bitcoin is not ruled by miners|miners]], so the deadlock was possible to solve by creating a [[user activated soft fork]] [[BIP 148]] where the [[economic majority]] would bypass the blocking miners and activate segregated witness on their own.
This required some coordination amongst the economic majority, but was ultimately successful, activating Segwit on Bitcoin soon after 1st August 2017.<ref>[https://web.archive.org/web/20210224032019/https://bitcoinmagazine.com/articles/long-road-segwit-how-bitcoins-biggest-protocol-upgrade-became-reality// BitcoinMagazine: The Long Road to SegWit: How Bitcoin’s Biggest Protocol Upgrade Became Reality (Archived February 2021)]</ref>

==See Also==

* [[BIP_0141|BIP 141]] Segregated Witness (Consensus layer)
* [[BIP_0143|BIP 143]] Transaction Signature Verification for Version 0 Witness Program
* [[BIP_0144|BIP 144]] Segregated Witness (Peer Services)
* [[BIP_0145|BIP 145]] getblocktemplate Updates for Segregated Witness
* [[BIP_0147|BIP 147]] Dealing with dummy stack element malleability
* [[BIP_0173|BIP 173]] Base32 address format for native v0-16 witness outputs
* [https://bitcoincore.org/en/2016/01/26/segwit-benefits/ Segregated Witness Benefits]
* [https://bitcoincore.org/en/segwit_wallet_dev/ Segregated Witness Wallet Developer Guide]
* [[Wikipedia:SegWit|Wikipedia: SegWit]]
{{stub}}

Genesis block

2021-03-14T06:08:17Z

Diegorodriguezv: /* Coinbase */ The word this started two paragraphs

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.

== Main network genesis block ==
Here is a representation of the genesis block<ref name="block">{{cite block|hash=000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f|0|year=2009|month=01|day=03}}</ref> as it appeared in a comment in an old version of Bitcoin ([http://sourceforge.net/p/bitcoin/code/133/tree/trunk/main.cpp#l1613 line 1613]). The first section defines exactly all of the variables necessary to recreate the block. The second section is the block in standard printblock format, which contains shortened versions of the data in the first section.

GetHash() = 0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
hashMerkleRoot = 0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b
txNew.vin[0].scriptSig = 486604799 4 0x736B6E616220726F662074756F6C69616220646E6F63657320666F206B6E697262206E6F20726F6C6C65636E61684320393030322F6E614A2F33302073656D695420656854
txNew.vout[0].nValue = 5000000000
txNew.vout[0].scriptPubKey = 0x5F1DF16B2B704C8A578D0BBAF74D385CDE12C11EE50455F3C438EF4C3FBCF649B6DE611FEAE06279A60939E028A8D65C10B73071A6F16719274855FEB0FD8A6704 OP_CHECKSIG
block.nVersion = 1
block.nTime = 1231006505
block.nBits = 0x1d00ffff
block.nNonce = 2083236893

CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
vMerkleTree: 4a5e1e
===Hash===
The hash of the genesis block, '''000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f''',<ref name="block"/> has two more leading hex zeroes than were required for an early block.

===Coinbase===
[[File:jonny1000thetimes.png|thumb|256px|The Times 03/Jan/2009]]
The [[coinbase]] parameter (seen above in hex) contains, along with the normal data, the following text:<ref>[http://web.archive.org/web/20140309004338/http://uk.reuters.com/article/2009/01/03/idUKPTIP32510920090103 Reuters' reference on The Financial Times article (archive.org cached copy)]</ref>

<blockquote>The Times 03/Jan/2009 Chancellor on brink of second bailout for banks<ref name="block"/></blockquote>

This was probably intended as proof that the block was created on or after January 3, 2009, as well as a comment on the instability caused by fractional-reserve banking. Additionally, it suggests that [[Satoshi Nakamoto]] may have lived in the United Kingdom.<ref>{{cite web|author=Davis, J.|year=2011|title=The Crypto-Currency|publisher=''The New Yorker''|url=http://www.newyorker.com/magazine/2011/10/10/the-crypto-currency}}</ref>

The detail "second bailout for banks" could also suggest that in a supposedly liberal and capitalist system, rescuing banks like that was a problem for Satoshi. The chosen topic could hint at bitcoin's purpose.

===Block reward===
The first 50 BTC block reward went to [[address]] ''1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa'',<ref name="block"/> though this reward can't be spent due to a quirk in the way that the genesis block is expressed in the code. It is not known if this was done intentionally or accidentally.<ref>http://bitcoin.stackexchange.com/questions/10009/why-can-t-the-genesis-block-coinbase-be-spent</ref><ref>https://www.reddit.com/r/Bitcoin/comments/1nc13r/the_first_50btc_block_reward_cant_be_spend_why/</ref><ref>https://github.com/bitcoin/bitcoin/blob/9546a977d354b2ec6cd8455538e68fe4ba343a44/src/main.cpp#L1668 - Genesis block transaction treated as a special case in the reference code</ref> It is believed that other outputs sent to this address are spendable, but it is unknown if Satoshi Nakamoto has the private key for this particular address, if one existed at all.

===Timestamp===
Although the average time between Bitcoin blocks is 10 minutes, the [[block timestamp|timestamp]] of the next block is a full 6 days after the genesis block. One interpretation is that Satoshi was working on bitcoin for some time beforehand and the ''The Times'' front page prompted him to release it to the public. He then mined the genesis block with a timestamp in the past to match the headline. It is also possible that, since the block's hash is so low, he may have spent 6 days mining it with the same timestamp before proceeding to block 1. The [[prenet hypothesis]] suggests that the genesis block was solved on January 3, but the software was tested by Satoshi Nakamoto using that genesis block until January 9, when all the test blocks were deleted and the genesis block was reused for the main network.

===Raw block data===

The [https://bitcointalk.org/index.php?topic=52706 raw hex version] of the Genesis block looks like:
00000000 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 3B A3 ED FD 7A 7B 12 B2 7A C7 2C 3E ....;£íýz{.²zÇ,>
00000030 67 76 8F 61 7F C8 1B C3 88 8A 51 32 3A 9F B8 AA gv.a.È.ÃˆŠQ2:Ÿ¸ª
00000040 4B 1E 5E 4A 29 AB 5F 49 FF FF 00 1D 1D AC 2B 7C K.^J)«_Iÿÿ...¬+|
00000050 01 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 ................
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070 00 00 00 00 00 00 FF FF FF FF 4D 04 FF FF 00 1D ......ÿÿÿÿM.ÿÿ..
00000080 01 04 45 54 68 65 20 54 69 6D 65 73 20 30 33 2F ..EThe Times 03/
00000090 4A 61 6E 2F 32 30 30 39 20 43 68 61 6E 63 65 6C Jan/2009 Chancel
000000A0 6C 6F 72 20 6F 6E 20 62 72 69 6E 6B 20 6F 66 20 lor on brink of
000000B0 73 65 63 6F 6E 64 20 62 61 69 6C 6F 75 74 20 66 second bailout f
000000C0 6F 72 20 62 61 6E 6B 73 FF FF FF FF 01 00 F2 05 or banksÿÿÿÿ..ò.
000000D0 2A 01 00 00 00 43 41 04 67 8A FD B0 FE 55 48 27 *....CA.gŠý°þUH'
000000E0 19 67 F1 A6 71 30 B7 10 5C D6 A8 28 E0 39 09 A6 .gñ¦q0·.\Ö¨(à9.¦
000000F0 79 62 E0 EA 1F 61 DE B6 49 F6 BC 3F 4C EF 38 C4 ybàê.aÞ¶Iö¼?Lï8Ä
00000100 F3 55 04 E5 1E C1 12 DE 5C 38 4D F7 BA 0B 8D 57 óU.å.Á.Þ\8M÷º..W
00000110 8A 4C 70 2B 6B F1 1D 5F AC 00 00 00 00 ŠLp+kñ._¬....

Broken down it looks like this:

01000000 - version
0000000000000000000000000000000000000000000000000000000000000000 - prev block
3BA3EDFD7A7B12B27AC72C3E67768F617FC81BC3888A51323A9FB8AA4B1E5E4A - merkle root
29AB5F49 - timestamp
FFFF001D - bits
1DAC2B7C - nonce
01 - number of transactions
01000000 - version
01 - input
0000000000000000000000000000000000000000000000000000000000000000FFFFFFFF - prev output
4D - script length
04FFFF001D0104455468652054696D65732030332F4A616E2F32303039204368616E63656C6C6F72206F6E206272696E6B206F66207365636F6E64206261696C6F757420666F722062616E6B73 - scriptsig
FFFFFFFF - sequence
01 - outputs
00F2052A01000000 - 50 BTC
43 - pk_script length
4104678AFDB0FE5548271967F1A67130B7105CD6A828E03909A67962E0EA1F61DEB649F6BC3F4CEF38C4F35504E51EC112DE5C384DF7BA0B8D578A4C702B6BF11D5FAC - pk_script
00000000 - lock time
==References==
<references/>

[[zh-cn:创世block]]
[[es:Bloque Génesis]]
__NOTOC__

[[Category:Technical]]

Genesis block

2021-03-14T06:06:15Z

Diegorodriguezv: /* Coinbase */ Fixed grammar and improved punctuation.

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.

== Main network genesis block ==
Here is a representation of the genesis block<ref name="block">{{cite block|hash=000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f|0|year=2009|month=01|day=03}}</ref> as it appeared in a comment in an old version of Bitcoin ([http://sourceforge.net/p/bitcoin/code/133/tree/trunk/main.cpp#l1613 line 1613]). The first section defines exactly all of the variables necessary to recreate the block. The second section is the block in standard printblock format, which contains shortened versions of the data in the first section.

GetHash() = 0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
hashMerkleRoot = 0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b
txNew.vin[0].scriptSig = 486604799 4 0x736B6E616220726F662074756F6C69616220646E6F63657320666F206B6E697262206E6F20726F6C6C65636E61684320393030322F6E614A2F33302073656D695420656854
txNew.vout[0].nValue = 5000000000
txNew.vout[0].scriptPubKey = 0x5F1DF16B2B704C8A578D0BBAF74D385CDE12C11EE50455F3C438EF4C3FBCF649B6DE611FEAE06279A60939E028A8D65C10B73071A6F16719274855FEB0FD8A6704 OP_CHECKSIG
block.nVersion = 1
block.nTime = 1231006505
block.nBits = 0x1d00ffff
block.nNonce = 2083236893

CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
vMerkleTree: 4a5e1e
===Hash===
The hash of the genesis block, '''000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f''',<ref name="block"/> has two more leading hex zeroes than were required for an early block.

===Coinbase===
[[File:jonny1000thetimes.png|thumb|256px|The Times 03/Jan/2009]]
The [[coinbase]] parameter (seen above in hex) contains, along with the normal data, the following text:<ref>[http://web.archive.org/web/20140309004338/http://uk.reuters.com/article/2009/01/03/idUKPTIP32510920090103 Reuters' reference on The Financial Times article (archive.org cached copy)]</ref>

<blockquote>The Times 03/Jan/2009 Chancellor on brink of second bailout for banks<ref name="block"/></blockquote>

This was probably intended as proof that the block was created on or after January 3, 2009, as well as a comment on the instability caused by fractional-reserve banking. Additionally, it suggests that [[Satoshi Nakamoto]] may have lived in the United Kingdom.<ref>{{cite web|author=Davis, J.|year=2011|title=The Crypto-Currency|publisher=''The New Yorker''|url=http://www.newyorker.com/magazine/2011/10/10/the-crypto-currency}}</ref>

This detail, "second bailout for banks" could also suggest that in a supposedly liberal and capitalist system, rescuing banks like that was a problem for Satoshi. The chosen topic could hint at bitcoin's purpose.

===Block reward===
The first 50 BTC block reward went to [[address]] ''1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa'',<ref name="block"/> though this reward can't be spent due to a quirk in the way that the genesis block is expressed in the code. It is not known if this was done intentionally or accidentally.<ref>http://bitcoin.stackexchange.com/questions/10009/why-can-t-the-genesis-block-coinbase-be-spent</ref><ref>https://www.reddit.com/r/Bitcoin/comments/1nc13r/the_first_50btc_block_reward_cant_be_spend_why/</ref><ref>https://github.com/bitcoin/bitcoin/blob/9546a977d354b2ec6cd8455538e68fe4ba343a44/src/main.cpp#L1668 - Genesis block transaction treated as a special case in the reference code</ref> It is believed that other outputs sent to this address are spendable, but it is unknown if Satoshi Nakamoto has the private key for this particular address, if one existed at all.

===Timestamp===
Although the average time between Bitcoin blocks is 10 minutes, the [[block timestamp|timestamp]] of the next block is a full 6 days after the genesis block. One interpretation is that Satoshi was working on bitcoin for some time beforehand and the ''The Times'' front page prompted him to release it to the public. He then mined the genesis block with a timestamp in the past to match the headline. It is also possible that, since the block's hash is so low, he may have spent 6 days mining it with the same timestamp before proceeding to block 1. The [[prenet hypothesis]] suggests that the genesis block was solved on January 3, but the software was tested by Satoshi Nakamoto using that genesis block until January 9, when all the test blocks were deleted and the genesis block was reused for the main network.

===Raw block data===

The [https://bitcointalk.org/index.php?topic=52706 raw hex version] of the Genesis block looks like:
00000000 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 3B A3 ED FD 7A 7B 12 B2 7A C7 2C 3E ....;£íýz{.²zÇ,>
00000030 67 76 8F 61 7F C8 1B C3 88 8A 51 32 3A 9F B8 AA gv.a.È.ÃˆŠQ2:Ÿ¸ª
00000040 4B 1E 5E 4A 29 AB 5F 49 FF FF 00 1D 1D AC 2B 7C K.^J)«_Iÿÿ...¬+|
00000050 01 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 ................
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070 00 00 00 00 00 00 FF FF FF FF 4D 04 FF FF 00 1D ......ÿÿÿÿM.ÿÿ..
00000080 01 04 45 54 68 65 20 54 69 6D 65 73 20 30 33 2F ..EThe Times 03/
00000090 4A 61 6E 2F 32 30 30 39 20 43 68 61 6E 63 65 6C Jan/2009 Chancel
000000A0 6C 6F 72 20 6F 6E 20 62 72 69 6E 6B 20 6F 66 20 lor on brink of
000000B0 73 65 63 6F 6E 64 20 62 61 69 6C 6F 75 74 20 66 second bailout f
000000C0 6F 72 20 62 61 6E 6B 73 FF FF FF FF 01 00 F2 05 or banksÿÿÿÿ..ò.
000000D0 2A 01 00 00 00 43 41 04 67 8A FD B0 FE 55 48 27 *....CA.gŠý°þUH'
000000E0 19 67 F1 A6 71 30 B7 10 5C D6 A8 28 E0 39 09 A6 .gñ¦q0·.\Ö¨(à9.¦
000000F0 79 62 E0 EA 1F 61 DE B6 49 F6 BC 3F 4C EF 38 C4 ybàê.aÞ¶Iö¼?Lï8Ä
00000100 F3 55 04 E5 1E C1 12 DE 5C 38 4D F7 BA 0B 8D 57 óU.å.Á.Þ\8M÷º..W
00000110 8A 4C 70 2B 6B F1 1D 5F AC 00 00 00 00 ŠLp+kñ._¬....

Broken down it looks like this:

01000000 - version
0000000000000000000000000000000000000000000000000000000000000000 - prev block
3BA3EDFD7A7B12B27AC72C3E67768F617FC81BC3888A51323A9FB8AA4B1E5E4A - merkle root
29AB5F49 - timestamp
FFFF001D - bits
1DAC2B7C - nonce
01 - number of transactions
01000000 - version
01 - input
0000000000000000000000000000000000000000000000000000000000000000FFFFFFFF - prev output
4D - script length
04FFFF001D0104455468652054696D65732030332F4A616E2F32303039204368616E63656C6C6F72206F6E206272696E6B206F66207365636F6E64206261696C6F757420666F722062616E6B73 - scriptsig
FFFFFFFF - sequence
01 - outputs
00F2052A01000000 - 50 BTC
43 - pk_script length
4104678AFDB0FE5548271967F1A67130B7105CD6A828E03909A67962E0EA1F61DEB649F6BC3F4CEF38C4F35504E51EC112DE5C384DF7BA0B8D578A4C702B6BF11D5FAC - pk_script
00000000 - lock time
==References==
<references/>

[[zh-cn:创世block]]
[[es:Bloque Génesis]]
__NOTOC__

[[Category:Technical]]