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.