This book constitutes the refereed proceedings of the 6th International Workshop on Information Security Applications, WISA 2005, held in Jeju Island, Korea, in August 2005.

The 29 revised full papers presented were carefully selected during two rounds of reviewing and improvement from 168 submissions. The papers are organized in topical sections on security analysis and attacks, systems security, network security, DRM/software security, efficient HW implementation, side-channel attacks, privacy/anonymity, and efficient implementation.