Since 1999, the workshop on Cryptographic Hardware and Embedded Systems (CHES) is the foremost international scientific event dedicated to all aspects of cryptographic hardware and security in embedded systems. Its 12th edition was held in Santa Barbara, California, USA, August 17–20, 2010. Exceptionally this year, it was co-located with the 30th International Cryptology Conference (CRYPTO). This co-location provided unique interaction opportunities for the communities of both events. As in previous years, CHES was sponsored by the International Association for Cryptologic Research (IACR).