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Cryptography and security applications make extensive use of random numbers and random bits, particularly for the generation of cryptographic keying material. A key to initiate a cryptographic algorithm needs to be unpredictable and statistically unique, that is, to have at most a negligible chance of repeating the value of a previously selected key. Selecting a key at random ensures that there is no known structure to the key selection process that an adversary might be able to use to determine the key, other than by an exhaustive search.
NIST is in the process of completing the development of approved methods for random bit generation.
This workshop discussed SP 800-90B and SP 800-90C, as well as their validation by NIST's validation programs.