Hashing

A cryptographic process that transforms input data into a fixed-length value to ensure data integrity.

Understanding Hashing

Hashing is a one-way function that transforms input data into a fixed-length string of characters. Unlike encryption, hashing is not reversible - you cannot derive the original input from the hash value. This property makes hashing particularly valuable for password storage, data integrity verification, and digital signatures.

Types of Hashing

Cryptographic Hash Functions

SHA-256, SHA-3, MD5 (deprecated)
Designed for security applications
Provide collision resistance
Generate fixed-length output

Non-cryptographic Hash Functions

MurmurHash, FNV
Optimized for speed and distribution
Used in hash tables and data structures
Not suitable for security applications

Challenges and Considerations

Security Concerns

Rainbow table attacks
Collision attacks
Preimage attacks
Birthday attacks

Implementation Issues

Performance overhead
Storage requirements
Algorithm selection
Compatibility concerns