These are the proceedings of CHES 2003, the ?fth workshop on Cryptographic HardwareandEmbeddedSystems, heldinCologneonSeptember8-10,2003.As with every previous workshop, there was a record number of submissions despite themuchearlierdeadlineinthisyear'scallforpapers.Thisisaclearindication of the growing international importance of the scope of the conference and the relevance of the subject material to both industry and academia. The increasing competition for presenting at the conference has led to many excellent papers and a higher standard overall. From the 111 submissions, time constraintsmeantthatonly32couldbeaccepted.Theprogramcommitteewo- ed very hard to select the best. However, at the end of the review process there were a number of good papers - which it would like to have included but for which, sadly, there was insu?cient space. In addition to the accepted papers appearing in this volume, there were three invited presentations from Hans D- bertin (Ruhr-Universit] at Bochum, Germany), Adi Shamir (Weizmann Institute, Israel), and Frank Stajano (University of Cambridge, UK), and a panel d- cussion on the e?ectiveness of current hardware and software countermeasures against side channel leakage in embedded cryptosystems."

This book constitutes the thoroughly refereed post-proceedings of the 4th International Workshop on Cryptographic Hardware and Embedded Systems, CHES 2002, held in Redwood Shores, California, USA in August 2002. The 41 revised full papers presented together with two invited contributions were carefully selected from 101 submissions during two rounds of reviewing and revision. The papers are organized in topical sections on attack strategies, finite field and modular arithmetic, elliptic curve cryptography, AES and AES candidates, tamper resistance, RSA implementation, random number generation, new primitives, hardware for cryptanalysis.

This book constitutes the thoroughly refereed post-proceedings of the Third International Workshop on Cryptoanalysis Hardware and Embedded Systems, CHES 2001, held in Paris, France in Mai 2001. The 31 revised full papers presented were carefully reviewed and selected from 66 submissions. The papers are organized in topical sections on side channel attacks, Rijndael hardware implementation, random number generators, elliptic curve algorithms, arithmetic architectures, cryptanalysis, embedded implementations of ciphers, and side channel attacks on elliptic curve cryptosystems.

This book constitutes the thoroughly refereed post-proceedings of the Second International Workshop on Cryptographic Hardware and Embedded Systems, CHES 2000, held in Worcester, MA, USA in August 2000. The 25 revised full papers presented together with two invited contributions were carefully reviewed and selected from 51 submissions. The papers are organized in topical sections on implementation of elliptic curve cryptosystems, power and timing analysis attacks, hardware implementation of block ciphers, hardware architectures, power analysis attacks, arithmetic architectures, physical security and cryptanalysis, and new schemes and algorithms.

This book constitutes the refereed proceedings of the First International Workshop on Cryptographic Hardware and Embedded Systems, CHES'99, held in Worcester, MA, USA in August 1999. The 27 revised papers presented together with three invited contributions were carefully reviewed and selected from 42 submissions. The papers are organized in sections on cryptographic hardware, hardware architectures, smartcards and embedded systems, arithmetic algorithms, power attacks, true random numbers, cryptographic algorithms on FPGAs, elliptic curve implementations, new cryptographic schemes and modes of operation.