A New Simple Authenticated Key Agreement and Protected Password Change Protocol

摘要

In 2005, Chang et al. proposed a simple authenticated key agreement and protected password change protocol. However, Chang et al.'s schemes are still susceptible to stolen-verifier attack and Denial-of-Service attacks. Accordingly, the current paper demonstrates the vulnerability of Chang et al.'s schemes to two simple attacks and then presents an improved scheme to resolve such problems. In contrast to Chang et al.'s protected password change protocol, the proposed protected password change protocol can securely update user passwords without a complicated process, while also providing greater security.