Cryptanalysis of modified authenticated key agreement protocol

Tseng [see ibid., vol. 36, no. 1, p. 48-9, 2000] addressed a weakness within and proposed a modification to the key agreement protocol presented by Seo and Sweeney [see ibid., vol. 35, no. 13, p. 1073-4, 1999]. The authors show that Tseng´s modified protocol is still vulnerable to two simple attacks and describe a new enhancement to the Seo-Sweeney protocol