RFC 2451 · PROPOSED STANDARD · 1998
WED · 29 JUL 2026
The ESP CBC-Mode Cipher Algorithms
Overview
RFC 2451, “The ESP CBC-Mode Cipher Algorithms”, is a Proposed Standard document published in November 1998 by R. Pereira, R. Adams. The canonical text is published by the RFC Editor.
Abstract
This document describes how to use CBC-mode cipher algorithms with the IPSec ESP (Encapsulating Security Payload) Protocol. It not only clearly states how to use certain cipher algorithms, but also how to use all CBC-mode cipher algorithms. [STANDARDS-TRACK]
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
Read this RFC
The canonical text of RFC 2451 is hosted at rfc-editor.org. Available in TXT,HTML.
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