This book constitutes the refereed proceedings of the 11th Australasian Conference on Information Security and Privacy, ACISP 2006, held in Melbourne, Australia in July 2006.

The 35 revised full papers presented together with 1 invited paper were carefully reviewed and selected from 133 submissions. The papers are organized in topical sections on stream ciphers, symmetric key ciphers, network security, cryptographic applications, secure implementation, signatures, theory, security applications, provable security, protocols, as well as hashing and message authentication.