Browse Prior Art Database

Privacy enhancement for Internet electronic mail: Part I - message encipherment and authentication procedures (RFC1113) Disclosure Number: IPCOM000001923D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2019-Feb-11
Document File: 34 page(s) / 51K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People


Related Documents

10.17487/RFC1113: DOI


This RFC specifies features for private electronic mail based on encryption technology. [STANDARDS-TRACK]

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 7% of the total text.

Network Working Group J. Linn Request for Comments: 1113 DEC Obsoletes RFCs: 989, 1040 IAB Privacy Task Force August 1989

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


This RFC suggests a draft standard elective protocol for the Internet community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited.


This RFC is the outgrowth of a series of IAB Privacy Task Force meetings and of internal working papers distributed for those meetings. I would like to thank the following Privacy Task Force members and meeting guests for their comments and contributions at the meetings which led to the preparation of this RFC: David Balenson, Curt Barker, Jim Bidzos, Matt Bishop, Danny Cohen, Tom Daniel, Charles Fox, Morrie Gasser, Russ Housley, Steve Kent (chairman), John Laws, Steve Lipner, Dan Nessett, Mike Padlipsky, Rob Shirey, Miles Smid, Steve Walker, and Steve Wilbur.

Table of Contents

1. Executive Summary 2 2. Terminology 3 3. Services, Constraints, and Implications 3 4. Processing of Messages 7 4.1 Message Processing Overview 7 4.1.1 Types of Keys 7 4.1.2 Processing Procedures 8 4.2 Encryption Algorithms and Modes 9 4.3 Privacy Enhancement Message Transformations 10 4.3.1 Constraints 10 4.3.2 Approach 11 Step 1: Local Form 12 Step 2: Canonical Form 12 Step 3: Authentication and Encipherment 12 Step 4: Printable Encoding 13 Summary of Transformations 15 4.4 Encapsulation Mechanism 15 4.5 Mail for Mailing Lists 17 4.6 Summary of Encapsulated Header Fields 18

Linn [Page 1]

RFC 1113 Mail Privacy: Procedures August 1989

4.6.1 Per-Message Encapsulated Header Fields 20 X-Proc-Type Field 20 X-DEK-Info Field 21 4.6.2 Encapsulated Header Fields Normally Per-Message 21 X-Sender-ID Field 22 X-Certificate Field 22 X-MIC-Info Field 23 4.6.3 Encapsulated Header Fields with Variable Occurrences 23 X-Issuer-Certificate Field 23 4.6.4 Per-Recipient Encapsulated Header Fields 24 X-Recipient-ID Field 24 X-Key-Info Field 24 Symmetric Key Management 24 Asymmetric Key Management 25 5. Key Management 26 5.1 Data Encrypting Keys (DEKs) 26 5.2 Interchange Keys (IKs) 26 5.2.1 Subfield Definitions 28 Entity Identifier Subfield 28 Issuing Authority Subfield 29 Version/Expiration Subfield 29 5.2.2 IK Cryptoperiod Issues 29 6. User Naming 29 6.1 Current Approach 29 6.2 Issues for Consideration 30 7. Example User Interface and Implementation 30 8. Areas For Further Study 31 9. References 32 NOTES 32

1. Executive Summary

This RFC defines message encipherment and authentication procedures, in order to provide privacy enhancement services for electronic mail transfer in the Internet. It is one member of a related set of four RFCs. The procedures defined in the current RFC are intended to be compatib...