Multiparty key agreement protocols

A class of multiparty key agreement protocols based on secret sharing is presented. The trust infrastructure necessary to achieve the intended security goals is discussed. Entity authentication is suggested to be replaced by a less expensive group authentication. Two key agreement protocols are discussed. The first is the group key agreement where all principals must be active to call the conference. The other allows a big enough subgroup (controlled by the threshold parameter t) to trigger the conference. It is proved that the protocols achieve key freshness, key confidentiality, group authentication and key confirmation. A discussion about possible modifications and extensions of the protocol concludes the paper.

[1]  Yvo Desmedt,et al.  A Secure and Efficient Conference Key Distribution System (Extended Abstract) , 1994, EUROCRYPT.

[2]  Serge Vaudenay,et al.  Authenticated Multi-Party Key Agreement , 1996, ASIACRYPT.

[3]  Adi Shamir,et al.  How to share a secret , 1979, CACM.

[4]  M. R. Titchener.  Construction and properties of the augmented and binary-depletion codes , 1985 .

[5]  Roger M. Needham,et al.  Using encryption for authentication in large networks of computers , 1978, CACM.

[6]  Chak-Kuen Wong,et al.  A conference key distribution system , 1982, IEEE Trans. Inf. Theory.

[7]  A. C. M. Fong,et al.  An improved algorithm for calculating the average synchronization delay of T-codes , 1999 .

[8]  Josef Pieprzyk,et al.  Changing Thresholds in the Absence of Secure Channels , 1999, Aust. Comput. J..

[9]  Alfred Menezes,et al.  Handbook of Applied Cryptography , 2018 .

[10]  Hugo Krawczyk,et al.  Proactive Secret Sharing Or: How to Cope With Perpetual Leakage , 1995, CRYPTO.

[11]  M. R. Titchener.  Digital encoding by means of new T-codes to provide improved data synchronisation and message integrity , 1984 .

[12]  G. R. BLAKLEY.  Safeguarding cryptographic keys , 1979, 1979 International Workshop on Managing Requirements Knowledge (MARK).

[13]  Douglas R. Stinson,et al.  Cryptography: Theory and Practice , 1995 .

[14]  Whitfield Diffie,et al.  New Directions in Cryptography , 1976, IEEE Trans. Inf. Theory.

[15]  Douglas R. Stinson,et al.  An explication of secret sharing schemes , 1992, Des. Codes Cryptogr..

[16]  G. R. Higgie.  Database of best T-codes , 1996 .

[17]  A. G. Williamson,et al.  Properties of low augmentation level T-codes , 1990 .

[18]  Paul C. van Oorschot,et al.  Authentication and authenticated key exchanges , 1992, Des. Codes Cryptogr..