On the security of an enhanced UMTS authentication and key agreement protocol

In this paper, we propose a practical and secure authentication and key agreement scheme for Universal Mobile Telecommunications System (UMTS). The paper introduces a new requirement, “home network should be partially trusted in an authentication scheme” to the UMTS. The scheme integrates symmetric and public key cryptosystem. Issues such as kinds of ”subscriber identity/location confidential” and ”non-repudiation services” are solved in the scheme. The paper provides computational analysis, messages transmission length analysis to the proposed scheme. Furthermore, comparisons with other schemes are also given. The results demonstrate that the proposed scheme is practical and secure.