Adi Shamir

Co-inventor of the RSA public-key cryptosystem, Shamir is an Israeli cryptographer whose initial in "RSA" stands for his name. He is also one of the inventors of the Feige–Fiat–Shamir identification scheme. His numerous inventions and contributions to cryptography include the Shamir secret sharing scheme, the breaking of the Merkle–Hellman knapsack cryptosystem, visual cryptography, and the TWIRL and TWINKLE factoring devices.

Together with Eli Biham, Shamir discovered differential cryptanalysis, a general method for attacking block ciphers. (It later emerged that differential cryptanalysis was already known—and kept a secret—by both IBM and the NSA.)