## What is a Cryptographic Hash? A cryptographic hash function takes an input string and converts it into a fixed-size sequence of characters (a digest). ### Key Properties of Hashing 1. **One-Way**: You cannot recover the input string from the hash digest. 2. **Deterministic**: The same input will always yield the exact same hash output. 3. **Collision Resistant**: Two different inputs should never produce the same hash. ### Comparing Algorithms - **MD5**: Extremely fast, but cracked. Ideal for basic checksum file validation, but never use for password security. - **SHA-1**: Legacy algorithm, now considered weak for security. - **SHA-256**: Part of the SHA-2 family, currently considered cryptographically secure and widely used in databases.