This book constitutes the refereed proceedings of the Second International Workshop on Practice and Theory in Public Key Cryptography, PKC'99, held in Kamakura, Japan in March 1999. The 25 revised full papers presented were carefully reviewed and selected from a total of 61 submissions. The volume reports most recent research results on all relevant aspects in public key cryptography. Among the topics covered are digital signatures, anonymous finger printing, message authentication, digital payment, key escrow, RSA systems, hash functions, decision oracles, random numbers, finite field computations, pay-per-view-systems, and electronic commerce.