A Tale of Two Entropy Source Validation Approaches: NIST 800 90B vs. BSI AIS 31 (G14a) Meltem Sonmez Turan is a cryptographer in the Computer Security Division of National Institute of Standards and Technology. Dr. Sonmez Turan’s research interests include symmetric cryptography, random number generation and statistical randomness testing. She has published several papers in international forums and served as a reviewer for the SHA3 hash function competition and the password hashing competition.