These are the pre-proceedings of CHES 2000, the second workshop on Cryp- graphicHardware andEmbedded Systems. The rst workshop, CHES'99, which was held at WPI in August 1999, was received quite enthusiastically by people in academia and industry who are interested in hardware and software imp- mentations of cryptography. We believe there has been a long-standing need for a workshop series combining theory and practice for integrating strong data - curity into modern communications and e-commerce applications. We are very glad that we had the opportunity to serve this purpose and to create the CHES workshop series. As is evident by the papers in these proceedings, there have been many excellentcontributions.Selectingthepapersforthisyear'sCHESwasnotaneasy task, and we regret that we had to reject several good papers due to the limited availability of time. There were 51 submitted contributions to CHES 2000, of which 25 were selected for presentation. This corresponds to a paper acceptance rate of 49% for this year, which is a decrease from the 64% acceptance rate for CHES'99.Allpaperswerereviewed.Inadditiontothecontributedpresentations, we have invited two speakers. As last year, the focus of the workshop is on all aspects of cryptographic hardware and embedded system design. Of special interest were contributions that describe new methods for e cient hardware implementations and hi- speed software for embedded systems, e.g., smart cards, microprocessors, DSPs, etc. In addition, there were again several very interesting and innovative - pers dealingwith cryptanalysis in practice, rangingfrom side-channel attacks to FPGA-based attack hardware.