RFC 3274 (rfc3274) - Page 1 of 6

Compressed Data Content Type for Cryptographic Message Syntax (CMS)

Network Working Group                                         P. Gutmann
Request for Comments: 3274                        University of Auckland
Category: Standards Track                                      June 2002


                   Compressed Data Content Type for
                   Cryptographic Message Syntax (CMS)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document defines a format for using compressed data as a
   Cryptographic Message Syntax (CMS) content type.  Compressing data
   before transmission provides a number of advantages, including the
   elimination of data redundancy which could help an attacker, speeding
   up processing by reducing the amount of data to be processed by later
   steps (such as signing or encryption), and reducing overall message
   size.  Although there have been proposals for adding compression at
   other levels (for example at the MIME or SSL level), these don't
   address the problem of compression of CMS content unless the
   compression is supplied by an external means (for example by
   intermixing MIME and CMS).

1. Introduction

   This document describes a compressed data content type for CMS.  This
   is implemented as a new ContentInfo type and is an extension to the
   types currently defined in CMS [RFC 2630].  CMS implementations SHOULD
   include support for the CompressedData content type.

   The format of the messages are described in ASN.1 [ASN1].









Gutmann                     Standards Track