Privacy Enhancement for Internet Electronic Mail: Part IV: Key Certification and Related Services (RFC1424)

Network Working Group B. Kaliski Request for Comments: 1424 RSA Laboratories February 1993

Privacy Enhancement for Internet Electronic Mail: Part IV: Key Certification and Related Services

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 product of many discussions at RSA Data Security, at Trusted Information Systems, and on the <pem- dev@tis.com> mailing list. Contributors include Dave Balenson, Jim Bidzos, Pat Cain, Vint Cerf, Pam Cochrane, Steve Dusse, Jeff Fassett, Craig Finseth, Jim Galvin, Mike Indovina, Bob Jueneman, Steve Kent, John Lowry, Paul McKenney, Jeff Thompson, and Charles Wu. This document is the product of the Privacy-Enhanced Electronic Mail Working Group.

1. Executive Summary

This document describes three types of service in support of Internet Privacy-Enhanced Mail (PEM) [1-3]: key certification, certificate- revocation list (CRL) storage, and CRL retrieval. Such services are among those required of an RFC 1422 [2] certification authority. Other services such as certificate revocation and certificate retrieval are left to the certification authority to define, although they may be based on the services described in this document.

Each service involves an electronic-mail request and an electronic- mail reply. The request is either an RFC 1421 [1] privacy-enhanced message or a message with a new syntax defined in this document. The new syntax follows the general RFC 1421 syntax but has a different process type, thereby distinguishing it from ordinary privacy- enhanced messages. The reply is either an RFC 1421 privacy-enhanced message, or an ordinary unstructured message.

Replies that are privacy-enhanced messages can be processed like any other privacy-enhanced message, so that the new certificate or the retrieved CRLs can be inserted into the requestor’s database during

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RFC 1424 Key Certification and Related Services February 1993

normal privacy-enhanced mail processing.

Certification authorities may also require non-electronic forms of request and may return non-electronic replies. It is expected that descriptions of such forms, which are outside the scope of this document, will be available through a certification authority’s "information" service.

2. Overview of Services

This section describes the three services in general terms.

The electronic-mail address to which requests are sent is left to the certification authority to specify. It is expected that certification authorities will advertise their addresses as part of an "information" service. Replies are sent to the address in the "Reply-To:" field of the request, and if that field is omitted, to the address in the "From:" field.

2.1...