The Cryptographers' Track (CT-RSA) is a research conference within the RSA conference, the largest, regularly staged computer security event. CT-RSA 2004 was the fourth year of the Cryptographers' Track, and it is now an established venue for presenting practical research results related to cryptography and data security. The conference received 77 submissions, and the program committee sel- ted 28 of these for presentation. The program committee worked very hard to evaluate the papers with respect to quality, originality, and relevance to cryp- graphy. Each paper was reviewed by at least three program committee members. Extended abstracts of the revised versions of these papers are in these proc- dings. The program also included two invited lectures by Dan Boneh and Silvio Micali. I am extremely grateful to the program committee members for their en- mous investment of time and e?ort in the di?cult and delicate process of review and selection. Many of them attended the program committee meeting during the Crypto 2003 conference at the University of California, Santa Barbara.

Inhalt

Symmetric Encryption.- Online Encryption Schemes: New Security Notions and Constructions.- Related-Key Attacks on Triple-DES and DESX Variants.- Design of AES Based on Dual Cipher and Composite Field.- Periodic Properties of Counter Assisted Stream Ciphers.- A Fast Correlation Attack via Unequal Error Correcting LDPC Codes.- Aymmetric Encryption.- k-Resilient Identity-Based Encryption in the Standard Model.- A Generic Construction for Intrusion-Resilient Public-Key Encryption.- Digital Signatures.- A Certificate-Based Signature Scheme.- Identity Based Undeniable Signatures.- Compressing Rabin Signatures.- Protocols.- A Key Recovery System as Secure as Factoring.- Server Assisted Signatures Revisited.- Cryptanalysis of a Zero-Knowledge Identification Protocol of Eurocrypt '95.- Universal Re-encryption for Mixnets.- Bit String Commitment Reductions with a Non-zero Rate.- Improving Robustness of PGP Keyrings by Conflict Detection.- Side-Channel Attacks.- Issues of Security with the Oswald-Aigner Exponentiation Algorithm.- Hardware Countermeasures against DPA - A Statistical Analysis of Their Effectiveness.- Self-Randomized Exponentiation Algorithms.- Hardwares.- Flexible Hardware Design for RSA and Elliptic Curve Cryptosystems.- High-Speed Modular Multiplication.- Yet Another Sieving Device.- Mode of Operations.- A Parallelizable Enciphering Mode.- Padding Oracle Attacks on the ISO CBC Mode Encryption Standard.- Hash and Hash Chains.- A 1 Gbit/s Partially Unrolled Architecture of Hash Functions SHA-1 and SHA-512.- Fast Verification of Hash Chains.- Visual Cryptography.- Almost Ideal Contrast Visual Cryptography with Reversing.- Ellictic Curve Cryptosystems.- Weak Fields for ECC.