This book constitutes the refereed proceedings of the Third International Conference on Cryptology in India, INDOCRYPT 2002, held in Hyderabad, India in December 2002. The 31 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 75 submissions. The papers are organized in topical sections on symmetric cyphers, new public-key schemes, foundations, public-key infrastructures, fingerprinting and watermarking, public-key protocols, Boolean functions, efficient and secure implementations, applications, anonymity, and secret sharing and oblivious transfer.

This book constitutes the refereed proceedings of the 5th International Conference on Cryptology in India, INDOCRYPT 2004, held in Chennai, India in December 2004. The 30 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 181 submissions. The papers are organized in topical sections on cryptographic protocols, applications, stream ciphers, cryptographic Boolean functions, foundations, block ciphers, public key encryption, efficient representations, public key cryptanalysis, modes of operation, signatures, and traitor tracing and visual cryptography.

This book constitutes the refereed proceedings of the 6th International Conference on Cryptology in India, INDOCRYPT 2005, held in Bangalore, India in December 2005. The 31 revised full papers presented together with 1 invited paper were carefully reviewed and selected from 148 submissions. The papers are organized in topical sections on sequences, boolean function and S-box, hash functions, design principles, cryptanalysis, time memory trade-off, new constructions, pairings, signatures, applications, e-cash, and implementations.

This book constitutes the refereed proceedings of the 4th International Conference on Cryptology in India, INDOCRYPT 2003, held in New Delhi, India in December 2003. The 29 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 101 submissions. The papers are organized in topical sections on stream ciphers, block ciphers, Boolean functions, secret sharing, bilinear pairings, public key cryptography, signature schemes, protocols, elliptic curve cryptography and algebraic geometry, implementation and digital watermarking, and authentication.

The third successful completion of the INDOCRYPT conference series marks the acceptance of the series by the international research community as a forum for presenting high-quality research.It also marks the coming of age of cryptology research in India. The authors for the submitted papers were spread across 21 countries and 4 continents, which goes a long way to demonstrate the international interest and visibility of INDOCRYPT.In the previous two conferences, the submissions from India originated from only two institutes; this increased to six for the 2002 conference.Thus INDOCRYPT is well set on the path to achieving two main ob jectives – to provide an international platform for presenting high-quality research and to stimulate cryptology research in India. The opportunity to serve as a program co-chair for the third INDOCRYPT carries a special satisfaction for the second editor.Way back in 1998, the sci- ti?c analysis group of DRDO organized a National Seminar on Cryptology and abbreviated it as NSCR.On attending the seminar, the second editor suggested that the conference name be changed to INDOCRYPT.It is nice to see that this suggestion was taken up, giving us the annual INDOCRYPT conference - ries.Of course, the form, character, and execution of the conference series was the combined e?ort of the entire Indian cryptographic community under the dynamic leadership of Bimal Roy.