orandom

Orandom refers to a pseudorandom number generator (PRNG) that was developed by the OpenBSD project. It is designed to be a cryptographically secure PRNG, meaning it is intended to be unpredictable even to an attacker with significant computational resources. Orandom is notable for its simplicity and its reliance on well-understood cryptographic primitives.

The design of Orandom is based on the idea of accumulating entropy from various sources within the operating system. This entropy is then mixed and used to seed a stream cipher. The stream cipher is employed to generate the pseudorandom output. This approach aims to ensure that the output is unpredictable and resistant to various forms of attack, such as state compromise or prediction.

Orandom is integrated into the OpenBSD operating system and is used for various security-sensitive applications, including key generation, random number requests from user-space applications, and other cryptographic operations. Its availability as a system-wide resource makes it a convenient and robust source of randomness for developers. The project's emphasis on security and public scrutiny means that Orandom has undergone extensive review and analysis by the cryptographic community.