## Cryptology ePrint Archive: Report 2009/057

Anonymity in Shared Symmetric Key Primitives

Gregory M. Zaverucha and Douglas R. Stinson

Abstract: We provide a stronger definition of anonymity in the context of shared symmetric key primitives, and show that existing schemes do not provide this level of anonymity. A new scheme is presented to share symmetric key operations amongst a set of participants according to a $(t,n)$-threshold access structure. We quantify the amount of information the output of the shared operation provides about the group of participants which collaborated to produce it.

Category / Keywords: secret-key cryptography / threshold cryptography