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Secure IPv6 Address Proxying using Multi-Key Cryptographically Generated Addresses (MCGAs)

Document Type Expired Internet-Draft (individual)
Expired & archived
Authors James Kempf , Craig Gentry
Last updated 2005-08-23
RFC stream (None)
Intended RFC status (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


RFC 3971 and 3972 (SEND) define a protocol for securing resolution of a statelessly autoconfigured IPv6 address to a link address as defined by IPv6 Neighbor Discovery. SEND does this by requiring the autoconfigured addresses to be cryptographically generated by the host from an RSA public key. However, one drawback of SEND is that such addresses cannot be securely proxied. Proxy Neighbor Discovery is important for Mobile IPv6 and in certain other cases. In this document, we describe an extension of SEND to addresses that are cryptographically generated using multiple public keys, called multi- key CGAs. Neighbor Discovery messages for multi-key CGAs are signed with an RSA ring signature, a type of signature that can be generated using the private key of any node from a group of nodes but which requires the public keys of all group members to verify. Multi-key CGAs can be securely proxied by all nodes that contribute keys to the address. The advantage of multi-key CGAs over other techniques of secure address proxying, such as trusting the router or using an attribute certificate, is that it preserves location privacy. A receiver cannot determine from the IPv6 address, ring signature, or cryptographic parameters whether the node or the proxy is defending the address, and hence whether the node is on or off the link.


James Kempf
Craig Gentry

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)