Software → Security
Hash Function
A function that maps input data of arbitrary size to a fixed-size value.
Motivation
Hash function solves the problem of mapping input data to a fixed-size value.
Where it fits
Hash Function appears in data structures, databases, security, and distributed systems.
Mental model
A hash is a deterministic fingerprint-like value, but different hash functions have different guarantees.
Common mistakes
- Using ordinary hash functions for password storage.
- Assuming hashes are always unique.
Related concepts
Hash Function connects to hash table, cryptographic hash, password hashing, and consistent hashing.