Hash functions are fundamental to computer security and data integrity. They convert any input into a fixed-size string of characters, serving as a digital fingerprint for data verification, password storage, and cryptographic applications.
Understanding Hash Algorithms
**MD5 (128-bit)**: Fast but cryptographically broken. Use only for checksums, not security.
**SHA-1 (160-bit)**: Also considered insecure for cryptographic purposes. Being phased out industry-wide.
**SHA-256 (256-bit)**: Part of the SHA-2 family. Secure and widely used. Recommended for most applications.
**SHA-512 (512-bit)**: Stronger variant of SHA-2. Slightly slower but provides higher security margin.
Common Hash Applications
- **Password Storage**: Store hashes instead of plain passwords - **File Integrity**: Verify downloads haven't been corrupted or tampered with - **Digital Signatures**: Foundation of PKI and certificate systems - **Data Deduplication**: Identify duplicate files without comparing content - **Blockchain**: Core component of cryptocurrency and distributed ledgers