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The Scientific World Journal
Volume 2014, Article ID 687879, 8 pages
Research Article

Security Analysis and Improvement of an Anonymous Authentication Scheme for Roaming Services

1Department of Cyber Investigation Police, Howon University, 64 3-gil, Gunsan, Jeollabuk-do 573-718, Republic of Korea
2Department of Computer Engineering, Sungkyunkwan University, 2066 Seoburo, Suwon, Gyeonggido 440-746, Republic of Korea

Received 7 August 2014; Accepted 25 August 2014; Published 11 September 2014

Academic Editor: Junghyun Nam

Copyright © 2014 Youngsook Lee and Juryon Paik. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An anonymous authentication scheme for roaming services in global mobility networks allows a mobile user visiting a foreign network to achieve mutual authentication and session key establishment with the foreign-network operator in an anonymous manner. In this work, we revisit He et al.’s anonymous authentication scheme for roaming services and present previously unpublished security weaknesses in the scheme: (1) it fails to provide user anonymity against any third party as well as the foreign agent, (2) it cannot protect the passwords of mobile users due to its vulnerability to an offline dictionary attack, and (3) it does not achieve session-key security against a man-in-the-middle attack. We also show how the security weaknesses of He et al.’s scheme can be addressed without degrading the efficiency of the scheme.