This book constitutes the refereed proceedings of the Third Australasian Conference on Information Security and Privacy, ACISP'98, held in Brisbane, Australia, in Kuly 1998. The volume presents 35 revised full papers selected from a total of 66 submissions; also included are two invited contributions. The book is divided in sections on network security, block ciphers, stream ciphers, authorization codes and Boolean functions, software security and electronic commerce, public key cryptography, hardware, access control, protocols, secret sharing, and digital signatures.