Lee Tian-Fu, Hwang Tzonelih
Department of Medical Informatics, Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, ROC.
Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan, ROC.
PLoS One. 2017 Mar 29;12(3):e0174473. doi: 10.1371/journal.pone.0174473. eCollection 2017.
Authenticated key agreements enable users to determine session keys, and to securely communicate with others over an insecure channel via the session keys. This study investigates the lower bounds on communications for three-party authenticated key agreements and considers whether or not the sub-keys for generating a session key can be revealed in the channel. Since two clients do not share any common secret key, they require the help of the server to authenticate their identities and exchange confidential and authenticated information over insecure networks. However, if the session key security is based on asymmetric cryptosystems, then revealing the sub-keys cannot compromise the session key. The clients can directly exchange the sub-keys and reduce the transmissions. In addition, authenticated key agreements were developed by using the derived results of the lower bounds on communications. Compared with related approaches, the proposed protocols had fewer transmissions and realized the lower bounds on communications.
认证密钥协商使用户能够确定会话密钥，并通过会话密钥在不安全的信道上与他人进行安全通信。本研究调查了三方认证密钥协商的通信下限，并考虑了生成会话密钥的子密钥是否会在信道中被泄露。由于两个客户端不共享任何公共密钥，它们需要服务器的帮助来认证其身份，并在不安全的网络上交换机密和经过认证的信息。然而，如果会话密钥安全性基于非对称密码系统，那么泄露子密钥不会危及会话密钥。客户端可以直接交换子密钥并减少传输量。此外，利用通信下限的推导结果开发了认证密钥协商。与相关方法相比，所提出的协议传输次数更少，并实现了通信下限。
