RFC 1421 (rfc1421) - Page 1 of 42


Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures



Alternative Format: Original Text Document



Network Working Group                                            J. Linn
Request for Comments: 1421                    IAB IRTF PSRG, IETF PEM WG
Obsoletes: 1113                                            February 1993


           Privacy Enhancement for Internet Electronic Mail:
        Part I: Message Encryption and Authentication Procedures

Status of this Memo

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

Acknowledgements

   This document is the outgrowth of a series of meetings of the Privacy
   and Security Research Group (PSRG) of the IRTF and the PEM Working
   Group of the IETF.  I would like to thank the members of the PSRG and
   the IETF PEM WG, as well as all participants in discussions on the
   "" mailing list, for their contributions to this
   document.

1.  Executive Summary

   This document defines message encryption and authentication
   procedures, in order to provide privacy-enhanced mail (PEM) services
   for electronic mail transfer in the Internet.  It is intended to
   become one member of a related set of four RFCs.  The procedures
   defined in the current document are intended to be compatible with a
   wide range of key management approaches, including both symmetric
   (secret-key) and asymmetric (public-key) approaches for encryption of
   data encrypting keys.  Use of symmetric cryptography for message text
   encryption and/or integrity check computation is anticipated. RFC
   1422 specifies supporting key management mechanisms based on the use
   of public-key certificates.  RFC 1423 specifies algorithms, modes,
   and associated identifiers relevant to the current RFC and to RFC
   1422.  RFC 1424 provides details of paper and electronic formats and
   procedures for the key management infrastructure being established in
   support of these services.

   Privacy enhancement services (confidentiality, authentication,
   message integrity assurance, and non-repudiation of origin) are
   offered through the use of end-to-end cryptography between originator
   and recipient processes at or above the User Agent level.  No special
   processing requirements are imposed on the Message Transfer System at



Linn