Deterministic Random Bit Generator

A Deterministic Random Bit Generator (DRBG) is a cryptographic algorithm that produces a sequence of random-looking bits from an initial seed value, ensuring the output is reproducible given the same seed. It is used in security applications where predictable randomness is required, such as generating encryption keys or nonces. Unlike true random number generators, DRBGs are deterministic, meaning they rely on mathematical functions rather than physical entropy sources.

Also known as: DRBG, Pseudo-Random Number Generator, PRNG, Cryptographic Random Number Generator, Deterministic Random Number Generator

Why learn Deterministic Random Bit Generator?

Developers should learn and use DRBGs in scenarios requiring secure and repeatable random number generation, such as in cryptographic protocols, simulations, or testing environments where reproducibility is essential. For example, in blockchain technology or secure communication systems, DRBGs help generate keys and random values that must be consistent across different runs while maintaining security against attacks.

Learning Resources

• docs: NIST Special Publication 800-90A: Recommendation for Random Number Generation Using Deterministic Random Bit Generators
• book: Cryptography Engineering: Design Principles and Practical Applications - Chapter on Random Number Generation
• video: Khan Academy: Random Number Generators in Cryptography
• course: Coursera: Cryptography I by Stanford University
• docs: OWASP Cryptographic Storage Cheat Sheet - Random Number Generation Section