Hash Algorithms Compared: MD5 vs SHA-256 vs SHA-3

Cryptographic hash functions are fundamental to modern security infrastructure. They convert arbitrary data into fixed-length outputs, enabling integrity verification and digital signatures.

MD5 — Deprecated

MD5 produces a 128-bit hash. It is cryptographically broken — collision attacks can be performed in seconds. Never use MD5 for security purposes.

SHA-256 — Recommended

Part of the SHA-2 family, SHA-256 produces a 256-bit hash. It is the industry standard for TLS certificates, code signing, and blockchain.

SHA-3 — Next Generation

SHA-3 uses a completely different internal structure (Keccak sponge construction). While SHA-2 remains secure, SHA-3 provides defense-in-depth against potential future attacks.

Quick Comparison

• File integrity checks — SHA-256 (or MD5 for non-security contexts)
• Password hashing — Use bcrypt, Argon2, or scrypt (not raw SHA)
• Digital signatures — SHA-256 or SHA-3
• Content addressing — SHA-256 (used by Git, Docker)