Author:
Kazuki Yoneyama
Affiliation:
The University of Electro-Communications, Japan
Keyword(s):
Anonymity, anonymous message authentication, universal composability, ring signature, group-certification authority.
Related
Ontology
Subjects/Areas/Topics:
Cryptographic Techniques and Key Management
;
Information and Systems Security
;
Public Key Crypto Applications
Abstract:
Recently, various casual communication tools which are run by a certain group (e.g., social network service, blog and Wiki) are popularized. In such services, a member may want to inform some information to other group members without exposing his identity. For this perpose, message authentication schemes which guarantee anonymity of senders seem to be suitable. In this paper, we introduce a new anonymous message authentication scheme using ring signature with a special certification authority, called group-certification authority. Our scheme does not need any group manager to preserve the anonymity of the group member by the property of ring signature. Therefore, our scheme is suitable to casual services where a strict operation is not required by a system manager. Furthermore, we evaluate the security of our scheme in the universal composability framework.