This book constitutes the refereed proceedings of the 13th Australasian Conference on Information Security and Privacy, ACISP 2008, held in Wollongong, Australia, in July 2008. The 33 revised full papers presented were carefully reviewed and selected from 111 submissions. The papers cover a range of topics in information security, including authentication, key management, public key cryptography, privacy, anonymity, secure communication, ciphers, network security, elliptic curves, hash functions, and database security.