This book constitutes the refereed proceedings of the 5th Australasian Conference on Information Security and Privacy, ACISP 2000, held in Brisbane, QLD, Australia, in July 2000.The 37 revised full papers presented together with two invited contributions were carefully reviewed and selected from a total of 81 submissions. The book offers topical sections on network security, public key cryptography, cryptographic implementation issues, electronic commerce, key recovery, public key infrastructure, Boolean functions, intrusion detection, codes, digital signatures, secret sharing, and prools.