Benny Pinkas
Israeli cryptographer who helped turn secure multiparty computation into something you can actually run — and who showed how badly both Windows and Linux were generating their random numbers.
Yao's garbled circuits from the 1980s proved in principle that two parties can compute a function of their secret inputs without revealing them to each other. Pinkas co-built Fairplay in 2004, one of the first systems to compile such protocols into runnable code, and with Yehuda Lindell gave the first complete security proof of Yao's construction. His work on private set intersection — comparing two lists and learning only the overlap — underpins today's contact-discovery and leaked-password checks.
More down to earth were his analyses of operating-system random number generators: Linux in 2006, Windows 2000 the year after. In the Windows case, earlier keys could be recomputed from a later state, and Microsoft conceded that XP had the same flaw.