Cryptographically Generated Addresses (CGA)
RFC 3972
| Document | Type |
RFC - Proposed Standard
(March 2005; No errata)
Was draft-ietf-send-cga (send WG)
|
|
|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 3972 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Margaret Wasserman | ||
| Send notices to | (None) | ||
Network Working Group T. Aura
Request for Comments: 3972 Microsoft Research
Category: Standards Track March 2005
Cryptographically Generated Addresses (CGA)
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2004).
Abstract
This document describes a method for binding a public signature key
to an IPv6 address in the Secure Neighbor Discovery (SEND) protocol.
Cryptographically Generated Addresses (CGA) are IPv6 addresses for
which the interface identifier is generated by computing a
cryptographic one-way hash function from a public key and auxiliary
parameters. The binding between the public key and the address can
be verified by re-computing the hash value and by comparing the hash
with the interface identifier. Messages sent from an IPv6 address
can be protected by attaching the public key and auxiliary parameters
and by signing the message with the corresponding private key. The
protection works without a certification authority or any security
infrastructure.
Aura Standards Track [Page 1]
RFC 3972 Cryptographically Generated Addresses March 2005
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. CGA Format . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. CGA Parameters and Hash Values . . . . . . . . . . . . . . . . 5
4. CGA Generation . . . . . . . . . . . . . . . . . . . . . . . . 6
5. CGA Verification . . . . . . . . . . . . . . . . . . . . . . . 9
6. CGA Signatures . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
7.1. Security Goals and Limitations . . . . . . . . . . . . . 12
7.2. Hash Extension . . . . . . . . . . . . . . . . . . . . . 13
7.3. Privacy Considerations . . . . . . . . . . . . . . . . . 15
7.4. Related Protocols . . . . . . . . . . . . . . . . . . . 15
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
A. Example of CGA Generation. . . . . . . . . . . . . . . . . 20
B. Acknowledgements . . . . . . . . . . . . . . . . . . . . . 21
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 21
Full Copyright Statements. . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
This document specifies a method for securely associating a
cryptographic public key with an IPv6 address in the Secure Neighbor
Discovery (SEND) protocol [RFC3971]. The basic idea is to generate
the interface identifier (i.e., the rightmost 64 bits) of the IPv6
address by computing a cryptographic hash of the public key. The
resulting IPv6 address is called a cryptographically generated
address (CGA). The corresponding private key can then be used to
sign messages sent from the address. An introduction to CGAs and
their application to SEND can be found in [Aura03] and [AAKMNR02].
This document specifies:
o how to generate a CGA from the cryptographic hash of a public key
and auxiliary parameters,
o how to verify the association between the public key and the CGA,
and
o how to sign a message sent from the CGA, and how to verify the
signature.
Aura Standards Track [Page 2]
RFC 3972 Cryptographically Generated Addresses March 2005
To verify the association between the address and the public key, the
verifier needs to know the address itself, the public key, and the
values of the auxiliary parameters. The verifier can then go on to
verify messages signed by the owner of the public key (i.e., the
address owner). No additional security infrastructure, such as a
public key infrastructure (PKI), certification authorities, or other
trusted servers, is needed.
Note that because CGAs themselves are not certified, an attacker can
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