This book constitutes the refereed proceedings of the 4th International Conference on Cryptology and Network Security, CANS 2005, held in Xiamen, China in December 2005. The 28 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 118 submissions. The papers are organized in topical sections on cryptanalysis, intrusion detection and viruses, authentication and signature, signcryption, e-mail security, cryptosystems, privacy and tracing, information hiding, firewalls, denial of service and DNS security, and trust management.Cryptanalysis
　The Second-Preimage Attack on MD4
　On the Security of Certificateless Signature Schemes from Asiacrypt 2003
　On the Security of a Group Signcryption Scheme from Distributed Signcryption Scheme
　Cryptanalysis of Two Group Key Management Protocols for Secure Multicast
　Security Analysis of Password-Authenticated Key Agreement Protocols
Intrusion Detection and Viruses
　An Immune-Based Model for Computer Virus Detection
　A New Model for Dynamic Intrusion Detection
　Self Debugging Mode for Patch-Independent Nullification of Unknown Remote Process Infection
　A New Unsupervised Anomaly Detection Framework for Detecting Network Attacks in Real-Time
Authentication and Signature
　ID-Based Aggregate Signatures from Bilinear Pairings
　Efficient Identity-Based Signatures and Blind Signatures
　How to Authenticate Real Time Streams Using Improved Online/Of[line Signatures
　New Authentication Scheme Based on a One-Way Hash Function and
　Diffie-Hellman Key Exchange
Signcryption
　Two Proxy Signcryption Schemes from Bilinear Pairings
　Constructing Secure Warrant-Based Proxy Signcryption Schemes
E-mail Security
　Design and Implementation of an Inline Certified E-mail Service
　Efficient Identity-Based Protocol for Fair Certified E-mail Delivery
Cryptosystems
　Similar Keys of Multivariate Quadratic Public Key Cryptosystems
　A Note on Signed Binary Window Algorithm for Elliptic Curve Cryptosystems
　Constructions of Almost Resilient Functions
Privacy and Tracing
Information Hiding
Firewalls,Denial of Service and DNS Security
Trust Management
Author Index