This text constitutes the thoroughly refereed post-proceedings of the 7th Annual International Workshop on Selected Areas in Cryptography, SAC 2000, held in Waterloo, Ontario, Canada, in August 2000. The 24 revised ful l papers presented were selected from 41 submissions and have gone through two rounds of reviewing and revision. The papers are organized in topical sections on cryptanalysis, block ciphers: new designs, elliptic curves and efficient implementations, security protocols and applications, block ciphers and hash functions, Boolean functions and stream ciphers, and public key...