E-mail protocols with perfect forward secrecy
Duncan S. Wong, Xiaojian Tian · International Journal of Security and Networks · 2012
In IEEE Communication Letters, Kim et al. and Sun et al. proposed several e–mail protocols and claimed that they provide perfect forward secrecy. In this paper, we show that under the assumption that the e–mail server is also malicious, Kim et al.'s two e–mail protocols do not provide perfect forward secrecy. While one of Sun et al.'s e–mail protocol provides perfect forward secrecy, it does not provide message authentication. We thus propose an improvement to Sun et al.'s e–mail protocol so that it provides both perfect forward secrecy and message authentication.