Definition of End-to-end Encryption
draft-knodel-e2ee-definition-00

Document Type Active Internet-Draft (individual)
Authors Mallory Knodel  , Fred Baker  , Olaf Kolkman  , Sofia Celi  , Gurshabad Grover 
Last updated 2021-02-22
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Model-T                                                        M. Knodel
Internet-Draft                                                       CDT
Intended status: Informational                                  F. Baker
Expires: August 26, 2021
                                                              O. Kolkman
                                                                    ISOC
                                                                 S. Celi
                                                              Cloudflare
                                                               G. Grover
                                         Centre for Internet and Society
                                                       February 22, 2021

                  Definition of End-to-end Encryption
                    draft-knodel-e2ee-definition-00

Abstract

   End-to-end encryption (E2EE) is an application of cryptography in
   communications systems between endpoints.  E2EE systems are unique in
   providing features of confidentiality, integrity and authenticity for
   users.  Improvements to E2EE strive to maximise the system's security
   while balancing usability and availability.  Users of E2EE
   communications expect trustworthy providers of secure implementations
   to respect and protect their right to whisper.

Status of This Memo

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   This Internet-Draft will expire on August 26, 2021.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

Knodel, et al.           Expires August 26, 2021                [Page 1]
Internet-Draft                    e2ee                     February 2021

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Formal definition of end-to-end encryption  . . . . . . . . .   3
     2.1.  End-to-end principle  . . . . . . . . . . . . . . . . . .   3
     2.2.  Encryption  . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  End-to-end encrypted systems design . . . . . . . . . . . . .   5
     3.1.  Features  . . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.1.  Necessary features  . . . . . . . . . . . . . . . . .   5
       3.1.2.  Optional/desirable features . . . . . . . . . . . . .   6
     3.2.  Challenges  . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  End-user expectations . . . . . . . . . . . . . . . . . . . .   8
     4.1.  A conversation is confidential  . . . . . . . . . . . . .   8
     4.2.  Providers are trustworthy . . . . . . . . . . . . . . . .   8
     4.3.  Access by a third-party is impossible . . . . . . . . . .   9
     4.4.  Pattern inference is minimised  . . . . . . . . . . . . .   9
     4.5.  The e2ee system is not compromised  . . . . . . . . . . .   9
   5.  Conclusions . . . . . . . . . . . . . . . . . . . . . . . . .  10
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   9.  Informative References  . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   This document defines end-to-end encryption (E2EE) using three
   different dimensions that together comprise a full definition of
   E2EE, which can be applied in a variety of contexts.

   The first is a formal definition that draws on the basic
   understanding of end points and cryptography.  The second looks at
   E2EE systems from a design perspective, both its fundamental features
   and the direction of travel towards improving those features.  Lastly
   we consider the expectations of the user of E2EE systems.
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