Randtype

Randtype is a label used in some software documentation to denote the class of randomness source or algorithm used to generate numbers. It may indicate distribution type (uniform, normal), randomness source (pseudo-random vs cryptographically secure), and determinism (seeded vs non-deterministic).

In software interfaces that generate random numbers, a parameter named randtype enables selection among backends or algorithms, supporting portability and reproducibility. Common categories include:

- PRNG (pseudo-random number generator) with deterministic sequences per seed.

- CSPRNG (cryptographically secure PRNG) with stronger unpredictability.

- True hardware RNG (where available) that uses physical processes.

Randtype can also indicate the statistical distribution used for sampling, such as uniform, normal, or exponential distributions.

Implementation considerations involve mapping the randtype to a specific RNG engine and a distribution sampler. The choice can affect performance, statistical properties, and reproducibility. Some environments require explicit seeding to achieve reproducibility; others may derive seeds from system entropy or internal state.

Security and reliability implications are tied to the randtype choice. Cryptographic or hardware-based randtypes are appropriate for keys, tokens, and other security-sensitive contexts, while PRNG-based randtypes suit simulations, testing, or non-critical randomness. Reproducibility typically depends on selecting an appropriate randtype in combination with a fixed seed.

See also: Random number generator, Pseudo-random number generator, Cryptographically secure PRNG, Entropy, Seeding, Statistical distribution.