Re-keying Mechanisms for Symmetric Keys
draft-irtf-cfrg-re-keying-05

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Last updated 2017-07-03
Replaces draft-cfrg-re-keying
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CFRG                                                  S. Smyshlyaev, Ed.
Internet-Draft                                                 CryptoPro
Intended status: Informational                              July 3, 2017
Expires: January 4, 2018

                Re-keying Mechanisms for Symmetric Keys
                      draft-irtf-cfrg-re-keying-05

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 external and
   internal re-keying mechanisms based on hash functions and on block
   ciphers, that can be used with modes of operations such as CTR, GCM,
   CCM, CBC, CFB, OFB and OMAC.

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   This Internet-Draft will expire on January 4, 2018.

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Smyshlyaev               Expires January 4, 2018                [Page 1]
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   5
   3.  Basic Terms and Definitions . . . . . . . . . . . . . . . . .   5
   4.  Choosing Constructions and Security Parameters  . . . . . . .   6
   5.  External Re-keying Mechanisms . . . . . . . . . . . . . . . .   8
     5.1.  Methods of Key Lifetime Control . . . . . . . . . . . . .  11
     5.2.  Parallel Constructions  . . . . . . . . . . . . . . . . .  12
       5.2.1.  Parallel Construction Based on a KDF on a Block
               Cipher  . . . . . . . . . . . . . . . . . . . . . . .  13
       5.2.2.  Parallel Construction Based on HKDF . . . . . . . . .  13
     5.3.  Serial Constructions  . . . . . . . . . . . . . . . . . .  14
       5.3.1.  Serial Construction Based on a KDF on a Block Cipher   14
       5.3.2.  Serial Construction Based on HKDF . . . . . . . . . .  15
   6.  Internal Re-keying Mechanisms . . . . . . . . . . . . . . . .  15
     6.1.  Methods of Key Lifetime Control . . . . . . . . . . . . .  18
     6.2.  Constructions that Do Not Require Master Key  . . . . . .  18
       6.2.1.  ACPKM Re-keying Mechanisms  . . . . . . . . . . . . .  18
       6.2.2.  CTR-ACPKM Encryption Mode . . . . . . . . . . . . . .  20
       6.2.3.  GCM-ACPKM Authenticated Encryption Mode . . . . . . .  22
       6.2.4.  CCM-ACPKM Authenticated Encryption Mode . . . . . . .  24
     6.3.  Constructions that Require Master Key . . . . . . . . . .  26
       6.3.1.  ACPKM-Master Key Derivation from the Master Key . . .  26
       6.3.2.  CTR-ACPKM-Master Encryption Mode  . . . . . . . . . .  27
       6.3.3.  GCM-ACPKM-Master Authenticated Encryption Mode  . . .  30
       6.3.4.  CCM-ACPKM-Master Authenticated Encryption Mode  . . .  33
       6.3.5.  CBC-ACPKM-Master Encryption Mode  . . . . . . . . . .  33
       6.3.6.  CFB-ACPKM-Master Encryption Mode  . . . . . . . . . .  35
       6.3.7.  OFB-ACPKM-Master Encryption Mode  . . . . . . . . . .  37
       6.3.8.  OMAC-ACPKM-Master Mode  . . . . . . . . . . . . . . .  39
   7.  Joint Usage of External and Internal Re-keying  . . . . . . .  40
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  40
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  41
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  41
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  42
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