Genesis block

Genesis block

Genesis block is the first block of a blockchain. 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 blockchain. 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.

Contents

What is Genesis block?

Here is a representation of the genesis block as it appeared in a comment in an old version of Bitcoin. 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 0x736B6E616220726F662074756F6C69616220646E6F63657320666F206B6E697262206E6F20726F6C6C
65636E61684320393030322F6E614A2F33302073656D695420656854 txNew.vout[0].nValue = 5000000000 txNew.vout[0].scriptPubKey = 0x5F1DF16B2B704C8A578D0BBAF74D385CDE12C11EE50455F3C438EF4C3FBCF649B6DE611FEAE06279
A60939E028A8D65C10B73071A6F16719274855FEB0FD8A6704 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 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e2
06272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73) CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B) vMerkleTree: 4a5e1e

The hash of the genesis block, has two more leading hex zeroes than were required for an early block.

Coinbase

The Times 03/Jan/2009

The Genesis block is the first block in the blockchain.

All cryptocurrencies have a Genesis block, but the first bitcoin block is more special as it was the first one.

Each block created from the moment of the zero block can automatically track it as its ancestor by means of links with the previous blocks.

Here is the block header hash for the Genesis block:

000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f 

The Genesis block contains a hidden message in the transaction: “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”.

This, of course, a note from Satoshi Nakamoto, has two functions:

  • first, the designation of the time to create the first block;
  • secondly, the reference to the economic problems of the current government and the banking system.

Genesis Block – Block reward

The first 50 BTC block reward went to address 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa

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 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 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  00000030 67 76 8F 61 7F C8 1B C3 88 8A 51 32 3A 9F B8 AA  00000040 4B 1E 5E 4A 29 AB 5F 49 FF FF 00 1D 1D AC 2B 7C  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  00000080 01 04 45 54 68 65 20 54 69 6D 65 73 20 30 33 2F  00000090 4A 61 6E 2F 32 30 30 39 20 43 68 61 6E 63 65 6C  000000A0 6C 6F 72 20 6F 6E 20 62 72 69 6E 6B 20 6F 66 20   000000B0 73 65 63 6F 6E 64 20 62 61 69 6C 6F 75 74 20 66  000000C0 6F 72 20 62 61 6E 6B 73 FF FF FF FF 01 00 F2 05  000000D0 2A 01 00 00 00 43 41 04 67 8A FD B0 FE 55 48 27  000000E0 19 67 F1 A6 71 30 B7 10 5C D6 A8 28 E0 39 09 A6  000000F0 79 62 E0 EA 1F 61 DE B6 49 F6 BC 3F 4C EF 38 C4  

00000100 F3 55 04 E5 1E C1 12 DE 5C 38 4D F7 BA 0B 8D 57

00000110 8A 4C 70 2B 6B F1 1D 5F AC 00 00 00 00    

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 04FFFF001D0104455468652054696D65732030332F4A616E2F32303039204368616E63656C6C6F72206F
6E206272696E6B206F66207365636F6E64206261696C6F757420666F722062616E6B73 - scriptsig FFFFFFFF - sequence 01 - outputs 00F2052A01000000 - 50 BTC 43 - pk_script length 4104678AFDB0FE5548271967F1A67130B7105CD6A828E03909A67962E0EA1F61DEB649F6BC3F4CEF38
C4F35504E51EC112DE5C384DF7BA0B8D578A4C702B6BF11D5FAC - pk_script 00000000 - lock time

External links

See Also on BitcoinWiki

References

http://www.newyorker.com/magazine/2011/10/10/the-crypto-currency.

http://bitcoin.stackexchange.com/questions/10009/why-can-t-the-genesis-block-coinbase-be-spent

https://www.reddit.com/r/Bitcoin/comments/1nc13r/the_first_50btc_block_reward_cant_be_spend_why/

https://github.com/bitcoin/bitcoin/blob/9546a977d354b2ec6cd8455538e68fe4ba343a44/src/main.cpp#L1668