Hash Function (Cryptographic Hash)
Also known as: Cryptographic Hash, Digital Fingerprint, One-Way Function
A mathematical algorithm that converts data into a fixed-size string, ensuring integrity and security in blockchain systems.
Cryptographic Methods
Intermediate level
A cryptographic hash function is a core component of blockchain technology that transforms any input data into a fixed-size output string, known as a hash. This process is irreversible and deterministic—meaning the same input always produces the same hash, but it's nearly impossible to derive the original input from the hash. Hash functions provide data integrity, digital fingerprinting, and are vital to consensus mechanisms like Proof of Work. Common algorithms include SHA-256 (used by Bitcoin) and Keccak-256 (used by Ethereum). They are also foundational to Merkle Trees, digital signatures, and block linking.