🔐 Crypto Hash Generator

What Is a Crypto Hash?

A cryptographic hash function takes any input and produces a fixed-length output (the hash). The same input always produces the same output, but even a tiny change in input produces a completely different hash. This property makes hashes useful for verifying data integrity.

Common Uses in Web3

• Ethereum function selectors: The first 4 bytes of the keccak256 hash of a function signature identify which function to call in a smart contract.
• Event topic IDs: keccak256 hashes of event signatures are used to filter Ethereum logs.
• IPFS content IDs: Files on IPFS are identified by the hash of their content.
• Merkle trees: Used in Ethereum state storage and Bitcoin transaction verification.
• Password storage: Never store plaintext passwords — store the hash.

Keccak256 vs SHA256

Ethereum uses Keccak256 (not the standardized SHA3-256). Bitcoin uses SHA256. For Ethereum development, use the ethers.js ethers.keccak256() function or the Web3.js equivalent for verified production results.