The Security Analysis On Authenticated Encryption Scheme

The CAESAR competition is a worldwide competition of authenticated encryption,which aims to find some final AE portfolio with good security and performance.There are many feature requirements in CAESAR competition,such as nonce-misuse resistance,intermediate tag,online encryption and so on.In this paper,we discuss those features and find the way to realize some important features.LAC,a leaked-state authenticated encryption,is one of the candidates of CAESAR competition.We present a forgery attack on LAC in nonce-misused case with time complexity 2^28.Moreover,we sort out the features of the second-round candidates in the CAESAR competition,list some well-designed candidates,such as AEZ,SHELL,etc,and explain how to realize those important features in the case of those candidates.Meanwhile,we also attempt to attack those candidates and find the defects of them.