This paper re-examines the security of three related block cipher modes of operation designed to provide authenticated encryption. These modes, known as PES-PCBC, IOBC and EPBC, were all proposed in the mid-1990s. However, analyses of security of the latter two modes were published more recently. In each case one or more papers describing security issues with the schemes were eventually published, although a flaw in one of these analyses (of EPBC) was subsequently discovered - this means that until now EPBC had no known major issues. This paper establishes that, despite this, all three schemes possess defects which should prevent their use - especially as there are a number of efficient alternative schemes possessing proofs of security.

翻译：本文重新审视了三种旨在提供认证加密的相关分组密码操作模式的安全性。这些模式，即PES-PCBC、IOBC和EPBC，均于20世纪90年代中期提出。然而，对后两种模式安全性的分析是近年才发表的。针对每种模式，最终都有一篇或多篇论文揭示了其安全缺陷，尽管其中一项分析（针对EPBC）后来被发现存在错误——这意味着在此之前EPBC尚未发现重大安全问题。本文证实，尽管如此，所有三种方案均存在缺陷，应避免使用——尤其是考虑到目前已有多种具备安全性证明的高效替代方案。