Adi Shamir is an Israeli cryptographer at the Weizmann Institute of Science who, together with Ron Rivest and Leonard Adleman, invented the RSA public-key cryptosystem in 1977 — the most widely deployed public-key algorithm in history. RSA is the foundation of secure communications on the internet, used in TLS/SSL for HTTPS, secure email, digital signatures, and key exchange protocols that protect trillions of dollars of electronic commerce annually. Shamir also invented Shamir's Secret Sharing scheme, which allows a secret to be split into shares such that any threshold number of shares can reconstruct the secret. Beyond RSA, he made fundamental contributions to cryptanalysis, including differential cryptanalysis (co-invented with Eli Biham), which broke DES-like ciphers and influenced the design of all subsequent block ciphers. He co-developed the SFLASH signature scheme, contributed to the cryptanalysis of stream ciphers, and has worked on physical-layer security attacks. Rivest, Shamir, and Adleman shared the 2002 ACM Turing Award.