We show several concrete attacks on an authenticated encryption scheme PAE which appeared in IEEE Transactions on Information Theory, Vol. 56, no. 8, pp. 4025–4037. Additionally we show some flaws and oversights in the analysis (presented in the same paper) used to prove PAE to be a secure authenticated encryption scheme.

In 1997, two new schemes for authenticated encryption, called signcryption, have been proposed by Zheng. In this paper we point out a serious problem with these schemes. In fact, the way to gain nonrepudiation violates the confidentiality. Moreover, we compare the schemes to previously known authenticated encryption schemes, which were not mentioned by Zheng. Finally we outline a solution that ...

Authenticated data structures are a model of computation where untrusted responders answer queries on a data structure on behalf of a trusted source and provide a proof of the validity of the answer to the user. We present a survey of techniques for designing authenticated data structures and overview their computational efficiency. We also discuss implementation issues and practical applications.