This book constitutes the thoroughly refereed post-proceedings of the First International Conference on Cryptology in Vietnam, VIETCRYPT 2006, held in Hanoi, Vietnam, September 2006. The 25 papers cover signatures and lightweight cryptography, pairing-based cryptography, algorithmic number theory, ring signatures and group signatures, hash functions, cryptanalysis, key agreement and threshold cryptography, as well as public-key encryption.

Signatures and Lightweight Cryptography.- Probabilistic Multivariate Cryptography.- Short 2-Move Undeniable Signatures.- Searching for Compact Algorithms: cgen.- Invited Talk.- On Pairing-Based Cryptosystems.- Pairing-Based Cryptography.- A New Signature Scheme Without Random Oracles from Bilinear Pairings.- Efficient Dynamic k-Times Anonymous Authentication.- Side Channel Analysis of Practical Pairing Implementations: Which Path Is More Secure?.- Algorithmic Number Theory.- Factorization of Square-Free Integers with High Bits Known.- Scalar Multiplication on Koblitz Curves Using Double Bases.- Compressed Jacobian Coordinates for OEF.- Ring Signatures and Group Signatures.- On the Definition of Anonymity for Ring Signatures.- Escrowed Linkability of Ring Signatures and Its Applications.- Dynamic Fully Anonymous Short Group Signatures.- Hash Functions.- Formalizing Human Ignorance.- Discrete Logarithm Variants of VSH.- How to Construct Sufficient Conditions for Hash Functions.- Cryptanalysis.- Improved Fast Correlation Attack on the Shrinking and Self-shrinking Generators.- On the Internal Structure of Alpha-MAC.- A Weak Key Class of XTEA for a Related-Key Rectangle Attack.- Key Agreement and Threshold Cryptography.- Deniable Group Key Agreement.- An Ideal and Robust Threshold RSA.- Towards Provably Secure Group Key Agreement Building on Group Theory.- Public-Key Encryption.- Universally Composable Identity-Based Encryption.- Traitor Tracing for Stateful Pirate Decoders with Constant Ciphertext Rate.- Reducing the Spread of Damage of Key Exposures in Key-Insulated Encryption.