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：本文重新审视了旨在提供认证加密的三种相关分组密码操作模式的安全性。这些模式被称为PES-PCBC、IOBC和EPBC，均于20世纪90年代中期提出。然而，对后两种模式的安全性分析直至最近才发表。在每种情况下，尽管最终都有一篇或多篇论文描述了这些方案的安全性问题，但其中一篇（关于EPBC）的分析后来被发现存在缺陷——这意味着直到现在，EPBC尚未被发现存在重大已知问题。本文确认，尽管如此，这三种方案均存在应阻止其使用的缺陷——尤其是考虑到存在许多具有安全性证明的高效替代方案。