Lenore Blum
American mathematician and the first B in Blum Blum Shub, the random number generator with a security proof.
Blum Blum Shub was published in 1986 by Lenore Blum, Manuel Blum and Michael Shub. The generator is almost provocatively simple: square the previous value modulo M = p·q, with both primes ≡ 3 mod 4, and output the least significant bit. Predicting its output is provably as hard as deciding quadratic residuosity, and so closely tied to factoring. The catch is speed, which is why it mostly lives on as the textbook example of a CSPRNG.
With Shub and Stephen Smale she also defined the BSS model of computation over the real numbers in 1989. She has been a professor at Carnegie Mellon and has spent decades pushing for women in mathematics and computer science.