Breaking Though the Limitation of Test Components Using in Authentication Test

Abstract

In order to break through the limitation that test components in authentication test cannot be encrypted, researchers have conducted plenty of extension study into strand space and made some achievements. Firstly, we analysis the new definitions and improved theorems raised by those researchers and point out their restriction and inaccuracy by way of strand theory and examples in this paper. Secondly, we propose in this paper a new definition named minimum encryption term, effectively limiting the number of forms in which components appear in strand space, lessening the redundancy of authentication test and simplifying the analysis process of nested term encryption. And, based on minimum encryption term, we provide improved authentication test theorems: NE outgoing test, NE incoming test and NE unsolicited test, which help to testify symmetric protocol and discover its flaws, that is, the protocol is an easy target of Man-In-The-Middle attack. These improved theorems increase the accuracy of authentication tests and extend its scope of use to both symmetric and asymmetric cryptosystem.