# Block Header Items For Block Hash Recreation - All Ethereum Eras There are currently 5 eras, each with a different concoction of block header elements/items needed in an exact order to re-create the exact block hash. Every major update that changed the block header, changed the way the block.hash was made. ### Cancun (Current latest era as of May 13th, 2024): ````javascript ```javascript // [19426587, Current] inclusive. Cancun --> Now async function rlpEncodeHeader(blockNumber) { // 1. Get the full block const block = await web3.eth.getBlock(blockNumber); // 2. Make array with only block header items. const blockHeader = [ block.parentHash, block.sha3Uncles, block.miner, block.stateRoot, block.transactionsRoot, block.receiptsRoot, block.logsBloom, block.difficulty, block.number, block.gasLimit, block.gasUsed, block.timestamp, block.extraData, block.mixHash, '0x0000000000000000', //block.nonce block.baseFeePerGas, block.withdrawalsRoot, block.blobGasUsed, block.excessBlobGas, block.parentBeaconBlockRoot, ]; // 3. RLP encode the block header, turning it into uint8 array. const encodedHeader = RLP.encode(blockHeader); // 4. Convert encoded header to a Buffer and then to hex so we can hash it. const encodedHeaderHex = '0x' + Buffer.from(encodedHeader).toString('hex'); // 5. Verification: Hash the encodedHeaderHex to check the recreated block hash matches actual block.hash const recreatedBlockHash = ethers.keccak256(encodedHeaderHex); console.log("recreated block hash:", recreatedBlockHash); console.log("actual block hash:", block.hash); assert.deepStrictEqual(recreatedBlockHash, block.hash); return encodedHeaderHex; } //rlpEncodeHeader(5800000); ``` ```` ### Shanghai -> Cancun: ````javascript ```javascript // [17034870, 19426586] inclusive. Shanghai-Capella --> Cancun-Deneb async function verifyShanghaiToCancunHash() { // 1. Get the full block const block = await web3.eth.getBlock(19010121); console.log(block.hash); // '0x8576cd4900e56c1214e2f32fbb194c0ebddde8cffd243194187977583d712aa5' // 2. Make array with only block header items. const blockHeader = [ block.parentHash, // '0x0607c9891abee48a5d70948d61d41ef7cabe554a8dd1aec49c6322ba7e2fab25' block.sha3Uncles, // '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347' block.miner, // '0x95222290dd7278aa3ddd389cc1e1d165cc4bafe5' block.stateRoot, // '0x0f90554fb8e825ce12c6ad7f0d5564e0197d6b41b4d6cf2a65175373795ef1fa' block.transactionsRoot, // '0xce8641939cdf1811521940f78609856d43a8eaf4e7b5c0a48e24c242cd57ec4b' block.receiptsRoot, // '0x52c2389675794511f8787f7a999019d9bfe9bfa9c6ec3b8544592241387d52aa' block.logsBloom, // '0x10a1d45047215b70ca08a790aa40920729bb9280ea453316106f832056a109a0193404ed0c01026300305933a870495813258a488813a4b8669d4644c0682180910ab60909c48d0a6b83c04e022c34f06199085db4fe19811143e213c832cd7209850550260ec14204c22a0c64646f020a30a8c01e008400c61621d4420850566032045603891962784d03d201620734430308930fb9130804c201437b700c622f43b1da4c80600365c04c86f8800cc40602a42103bc00222131a90601ce040055044e035af412610422ba2310c80a4c2dc023729669081405df1546c10120130098e001394c0102286c50252810ad44dea07930211814440a009c3c80630c21' block.difficulty, // 0n ('0x') block.number, // 19010121n ('0x1221249') block.gasLimit, // 30000000n ('0x1c9c380') block.gasUsed, // 12044352n ('0xb7c840') block.timestamp, // 1705295603n ('0x65a4bef3') block.extraData, // '0x6265617665726275696c642e6f7267' block.mixHash, // '0x84376d868db109d93e3062b04daa8a4f50e8ac872a0807eb740d306a395dc7d6' '0x0000000000000000', //block.nonce MUST BE 16 ZEROs IN THIS ERA! block.baseFeePerGas, // 16698450961n ('0x3e34e2411') block.withdrawalsRoot, // '0x3e72aaa4c11c1c04da24b4e2e40709b8a0795e877997921ab5806acd890c1054' ]; console.log(blockHeader); // 3. RLP encode the block header, turning it into uint8 array with 534 entries. const encodedHeader = RLP.encode(blockHeader); console.log(encodedHeader); // 4. Convert encoded header to a Buffer and then to hex so we can hash it. const encodedHeaderHex = Buffer.from(encodedHeader).toString('hex'); console.log(encodedHeaderHex); // 5. Hash the encodedHex to verify block hash const recreatedBlockHash = ethers.keccak256('0x' + encodedHeaderHex); console.log(recreatedBlockHash); assert.deepStrictEqual(recreatedBlockHash, block.hash); // Successfully matches the actal block hash! } //verifyShanghaiToCancunHash(); ``` ```` ### Paris -> Shanghai ````javascript ```javascript // [15537394, 17034869] inclusive. Paris --> Shanghai async function verifyHashParisToShanghai() { // 1. Get the full block const block = await web3.eth.getBlock(16000000); console.log(block.hash); // '0x3dc4ef568ae2635db1419c5fec55c4a9322c05302ae527cd40bff380c1d465dd' // 2. Make array with only block header items. const blockHeader = [ block.parentHash, // '0x6f377dc6bd1f3e38b9ceb8c946a88c13211fa3f084622df3ee5cfcd98cc6bb16' block.sha3Uncles, // '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347' block.miner, // '0xebec795c9c8bbd61ffc14a6662944748f299cacf' block.stateRoot, // '0xe5608defce0c3e193b4c2e3452ece5158e6ae35db211925cdfb4cd307587bbf0' block.transactionsRoot, // '0xe0265e44b4639453428546d1c0046c9fbba7d679b7be3e67692904c776389890' block.receiptsRoot, // '0x63c77297d9aace97c33e40c07c4f7d52f62e898f9be74f43ae8f8b751012e719' block.logsBloom, // '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' block.difficulty, // 0n ('0x') block.number, // 16000000n ('0xf42400') block.gasLimit, // 30000000n ('0x1c9c380') block.gasUsed, // 18992639n ('0x121cdff') block.timestamp, // 1668811907n ('0x63780c83') block.extraData, // '0x4d616465206f6e20746865206d6f6f6e20627920426c6f636b6e6174697665' block.mixHash, // '0xe197021bc2912013a6c5e3a42fa1260f00d80ad389a9f7137a5dafdaef38977a' '0x0000000000000000', // block.nonce. MUST HAVE 16 ZEROs IN THIS ERA block.baseFeePerGas, // 11130414489n ('0x2976ca599') ]; console.log(blockHeader); // 3. RLP encode the block header, turning it into uint8 array. const encodedHeader = RLP.encode(blockHeader); console.log(encodedHeader); // 4. Convert encoded header to a Buffer and then to hex so we can hash it. const encodedHeaderHex = Buffer.from(encodedHeader).toString('hex'); console.log(encodedHeaderHex); // 5. Hash the encodedHeaderHex to verify block hash const recreatedBlockHash = ethers.keccak256('0x' + encodedHeaderHex); console.log(recreatedBlockHash); assert.deepStrictEqual(recreatedBlockHash, block.hash); // Successfully matches the actal block hash! } //verifyHashParisToShanghai(); ``` ```` ### London -> Paris (The Merge) ````javascript ```javascript // [12965000, 15537393] inclusive. London --> Paris (The Merge). async function verifyHashLondonToParisBlocks() { // 1. Get the full block const block = await web3.eth.getBlock(14000000); console.log(block.hash); // ' // 2. Make array with only block header items. const blockHeader = [ block.parentHash, // '0x0c9ef41f038aa58a4aa2810fda03d9d82aac9082c80283230fd74cb1cceb4b00' block.sha3Uncles, // '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347' block.miner, // '0xea674fdde714fd979de3edf0f56aa9716b898ec8' block.stateRoot, // '0xfb3df73e7a41d500a374ee236dd613bb24f1a5fa5b80615a7953ea75c26c6a6d' block.transactionsRoot, // '0x16b6ff83df3ef14f614c70ac29e8a05d102c6bed0e5882c284abf0120b89529c' block.receiptsRoot, // '0xf7b9f8e92a4b420a27302ab91084e5499d3d711183a021f4956ff32de246e14e' block.logsBloom, // '0x083815041300081040f485088003de10046040491c3c0164189830ca3c2c0d1121040493008ba600924849820c8901130b0084038802610706000b6101b220d01210000400020b08480850880d0226a04024e107005114513410021080080451126063400a1084021c62bc08290008a0430081540c892545360c401410194021426103228249162800ac016601100d0520b96203432080086a00424d8214010b63180471318634d0ae00108041a1184488a10841a2610e0401e9001a504a4010098182020808155027009c02008e56070c28728114480490400801cac010290ae291a00ca0408b60204c128012601c100a24cc01e100897242832a825000c1e1' block.difficulty, // 12316581093827601n ('0x2bc1dd80f1e411') block.number, // 14000000n ('0xd59f80') block.gasLimit, // 30058561n ('0x1caa841') block.gasUsed, // 8119826n ('0x7be612') block.timestamp, // 1642114795n ('0x61e0aeeb') block.extraData, // '0x6175737472616c69612d736f75746865617374312d31' block.mixHash, // '0xa832679fcf3e71f0b29bd5913955151be5bf1fc59e135e3c7eb6e30f8442a5df' block.nonce, // 3596099692050383908n ('0x31e7e99df18e0424') block.baseFeePerGas, // 139541559304n ('0x207d533808') ]; console.log(blockHeader); // 3. RLP encode the block header, turning it into uint8 array. const encodedHeader = RLP.encode(blockHeader); console.log(encodedHeader); // 4. Convert encoded header to a Buffer and then to hex so we can hash it. const encodedHeaderHex = Buffer.from(encodedHeader).toString('hex'); console.log(encodedHeaderHex); // 5. Hash the encodedHeaderHex to verify block hash const recreatedBlockHash = ethers.keccak256('0x' + encodedHeaderHex); console.log(recreatedBlockHash); assert.deepStrictEqual(recreatedBlockHash, block.hash); // Successfully matches the actal block hash! } //verifyHashLondonToParisBlocks(); ``` ```` ### Genesis -> London ````javascript ```javascript // [1, 12964999] inclusive. Genesis --> London. async function verifyHashGenesisToLondonBlocks() { // 1. Get the full block const block = await web3.eth.getBlock(400000); console.log(block.hash); // '0x5d15649e25d8f3e2c0374946078539d200710afc977cdfc6a977bd23f20fa8e8' // 2. Make array with only block header items. const blockHeader = [ block.parentHash, // '0x1e77d8f1267348b516ebc4f4da1e2aa59f85f0cbd853949500ffac8bfc38ba14' block.sha3Uncles, // '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347' block.miner, // '0x2a65aca4d5fc5b5c859090a6c34d164135398226' block.stateRoot, // '0x0b5e4386680f43c224c5c037efc0b645c8e1c3f6b30da0eec07272b4e6f8cd89' block.transactionsRoot, // '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421' block.receiptsRoot, // '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421' block.logsBloom, // '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000' block.difficulty, // 6022643743806n ('0x57a418a7c3e') block.number, // 400000n ('0x61a80') block.gasLimit, // 3141592n ('0x2fefd8') block.gasUsed, // 0n ('0x') block.timestamp, // 1445130204n ('0x5622efdc') block.extraData, // '0xd583010202844765746885676f312e35856c696e7578' block.mixHash, // '0x3fbea7af642a4e20cd93a945a1f5e23bd72fc5261153e09102cf718980aeff38' block.nonce // 7706288617141211887n ('0x6af23caae95692ef') ]; console.log(blockHeader); // 3. RLP encode the block header, turning it into uint8 array. const encodedHeader = RLP.encode(blockHeader); console.log(encodedHeader); // 4. Convert encoded header to a Buffer and then to hex so we can hash it. const encodedHeaderHex = Buffer.from(encodedHeader).toString('hex'); console.log(encodedHeaderHex); // 5. Hash the encodedHeaderHex to verify block hash const recreatedBlockHash = ethers.keccak256('0x' + encodedHeaderHex); console.log(recreatedBlockHash); assert.deepStrictEqual(recreatedBlockHash, block.hash); // Successfully matches the actal block hash! } //verifyHashGenesisToLondonBlocks(); ``` ```` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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