Re-keying Mechanisms for Symmetric Keys
draft-irtf-cfrg-re-keying-13

Document Type Active Internet-Draft (cfrg RG)
Last updated 2018-08-17
Replaces draft-cfrg-re-keying
Stream IRTF
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CFRG                                                  S. Smyshlyaev, Ed.
Internet-Draft                                                 CryptoPro
Intended status: Informational                           August 17, 2018
Expires: February 18, 2019

                Re-keying Mechanisms for Symmetric Keys
                      draft-irtf-cfrg-re-keying-13

Abstract

   A certain maximum amount of data can be safely encrypted when
   encryption is performed under a single key.  This amount is called
   "key lifetime".  This specification describes a variety of methods to
   increase the lifetime of symmetric keys.  It provides two types of
   re-keying mechanisms based on hash functions and on block ciphers,
   that can be used with modes of operations such as CTR, GCM, CBC, CFB
   and OMAC.

   This document is a product of the Crypto Forum Research Group (CFRG)
   in the IRTF.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on February 18, 2019.

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   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents

Smyshlyaev              Expires February 18, 2019               [Page 1]
Internet-Draft   Re-keying Mechanisms for Symmetric Keys     August 2018

   carefully, as they describe your rights and restrictions with respect
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   6
   3.  Basic Terms and Definitions . . . . . . . . . . . . . . . . .   6
   4.  Choosing Constructions and Security Parameters  . . . . . . .   8
   5.  External Re-keying Mechanisms . . . . . . . . . . . . . . . .  10
     5.1.  Methods of Key Lifetime Control . . . . . . . . . . . . .  13
     5.2.  Parallel Constructions  . . . . . . . . . . . . . . . . .  13
       5.2.1.  Parallel Construction Based on a KDF on a Block
               Cipher  . . . . . . . . . . . . . . . . . . . . . . .  14
       5.2.2.  Parallel Construction Based on a KDF on a Hash
               Function  . . . . . . . . . . . . . . . . . . . . . .  14
       5.2.3.  Tree-based Construction . . . . . . . . . . . . . . .  15
     5.3.  Serial Constructions  . . . . . . . . . . . . . . . . . .  16
       5.3.1.  Serial Construction Based on a KDF on a Block Cipher   17
       5.3.2.  Serial Construction Based on a KDF on a Hash Function  18
     5.4.  Using Additional Entropy during Re-keying . . . . . . . .  18
   6.  Internal Re-keying Mechanisms . . . . . . . . . . . . . . . .  19
     6.1.  Methods of Key Lifetime Control . . . . . . . . . . . . .  21
     6.2.  Constructions that Do Not Require Master Key  . . . . . .  22
       6.2.1.  ACPKM Re-keying Mechanisms  . . . . . . . . . . . . .  22
       6.2.2.  CTR-ACPKM Encryption Mode . . . . . . . . . . . . . .  24
       6.2.3.  GCM-ACPKM Authenticated Encryption Mode . . . . . . .  26
     6.3.  Constructions that Require Master Key . . . . . . . . . .  28
       6.3.1.  ACPKM-Master Key Derivation from the Master Key . . .  28
       6.3.2.  CTR-ACPKM-Master Encryption Mode  . . . . . . . . . .  30
       6.3.3.  GCM-ACPKM-Master Authenticated Encryption Mode  . . .  32
       6.3.4.  CBC-ACPKM-Master Encryption Mode  . . . . . . . . . .  34
       6.3.5.  CFB-ACPKM-Master Encryption Mode  . . . . . . . . . .  37
       6.3.6.  OMAC-ACPKM-Master Authentication Mode . . . . . . . .  39
   7.  Joint Usage of External and Internal Re-keying  . . . . . . .  40
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  41
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  42
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  42
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  43
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