This book constitutes the refereed proceedings of the 5th International Conference on Cryptology and Network Security, CANS 2006, held in Suzhou, China, December 2006. The 26 revised full papers and 2 invited papers cover encryption, authentication and signatures, proxy signatures, cryptanalysis, implementation, steganalysis and watermarking, boolean functions and stream ciphers, intrusion detection, and disponibility and reliability.

Encryption.- Concrete Chosen-Ciphertext Secure Encryption from Subgroup Membership Problems.- Efficient Identity-Based Encryption with Tight Security Reduction.- Key Exchange.- A Diffie-Hellman Key Exchange Protocol Without Random Oracles.- Authenticated Group Key Agreement for Multicast.- Authenticated and Communication Efficient Group Key Agreement for Clustered Ad Hoc Networks.- Authentication and Signatures.- Efficient Mutual Data Authentication Using Manually Authenticated Strings.- Achieving Multicast Stream Authentication Using MDS Codes.- Shorter Verifier-Local Revocation Group Signatures from Bilinear Maps.- Proxy Signatures.- Security Model of Proxy-Multi Signature Schemes.- Efficient ID-Based One-Time Proxy Signature and Its Application in E-Cheque.- Cryptanalysis.- Side Channel Attacks and Countermeasures on Pairing Based Cryptosystems over Binary Fields.- Improved Collision Attack on Reduced Round Camellia.- Stealing Secrets with SSL/TLS and SSH - Kleptographic Attacks.- Implementation.- Bitslice Implementation of AES.- A Fast Algorithm for Determining the Linear Complexity of Periodic Sequences over GF(3).- Steganalysis and Watermarking.- Steganalysis Based on Differential Statistics.- Watermarking Essential Data Structures for Copyright Protection.- Boolean Functions and Stream Ciphers.- A Note of Perfect Nonlinear Functions.- Chaotic Keystream Generator Using Coupled NDFs with Parameter Perturbing.- Intrusion Detection.- Cooperative Intrusion Detection for Web Applications.- Finding TCP Packet Round-Trip Time for Intrusion Detection: Algorithm and Analysis.- Smart Architecture for High-Speed Intrusion Detection and Prevention Systems.- A Multi-agent Cooperative Model and System for Integrated Security Monitoring.- Disponibility and Reliability.-Detecting DDoS Attacks Based on Multi-stream Fused HMM in Source-End Network.- An Immune-Based Model for Service Survivability.- X2BT Trusted Reputation System: A Robust Mechanism for P2P Networks.