noncryptographic

Noncryptographic refers to algorithms, functions, or systems that do not rely on cryptographic assumptions or provide cryptographic security properties. In practice, noncryptographic techniques emphasize speed, simplicity, and efficiency, with little to no resistance to cryptographic attacks.

Common areas of noncryptographic use include hashing and random number generation for non-security purposes. Noncryptographic hash functions are designed to be fast and suitable for data indexing, checksums, and deduplication, rather than for cryptographic security. Examples include MurmurHash, CityHash, and FNV-1a. By contrast, cryptographic hash functions (such as SHA-256 or BLAKE3) aim to provide preimage resistance, second-preimage resistance, and collision resistance. CRCs and Adler-32, while useful for error detection, are not intended to provide cryptographic security.

Noncryptographic random number generators, such as the Mersenne Twister, can produce high-quality randomness for simulations and statistical sampling but are not suitable for security-critical tasks. Cryptographically secure RNGs or pseudo-random number generators designed for security use are required when randomness must be unpredictable to adversaries.

Key distinctions include the intended guarantees and threat models. Noncryptographic tools do not protect against tampering, disclosure, or impersonation and should not be used for security-sensitive purposes. When security is required, cryptographic primitives—such as cryptographic hashes, digital signatures, message authentication codes, and CSPRNGs—should be used instead. See also cryptographic hash function and cryptographically secure RNG.