無需公開金匙密碼系統之高效能密碼驗證機制

Abstract

In 2000, Peyravian and Zunic proposed a password authentication scheme which only uses a one-way hash function. However, the Peyravian- Zunic scheme only achieves one-way authentication, and it cannot withstand guessing attack and stolen-verifier attack. In 2002, Hwang and Yeh gave an improvement on the Peyravian- Zunic scheme by using a public key cryptosystem. In 2003, Lin and Hwang showed that the Hwang-Yeh scheme is vulnerable to a denial of service attack and further proposed an improvement. In this paper, we will analyze the security of the Hwang-Yeh scheme and the Lin-Hwang scheme and also give an improvement. The improved scheme is more efficient than the previous three schemes.