Public Key Cryptography - PKC 2003

PKC 2003 was the Sixth International Workshop on Practice and Theory in Public Key Cryptography and was sponsored by IACR, the International As- ciation for Cryptologic Research (www.iacr.org). I am very grateful to the members of the Program Committee for their hard work in the di?cult task of selecting roughly 1 out of 4 of the submitted papers.