Subject: Re: [Ace] New Version Notification for draft-selander-ace-cose-ecdhe-10.txt

From: John Mattsson <[email-masked]>
Date: Tue, 18 Sep 2018 12:13:48 +0000

Hi,

We just submitted version 10 of EDHOC, the new version adds quite a lot of clarifications and examples and adds some new optimizations. In particular:

- The introduction has been expanded to better describe the security properties of EDHOC, the motivation behind it, and the structure of the document.
- The key derivation is described in terms of a function EDHOC-Key-Derivation(AlgorithmID, keyDataLength, other) and an Exporter interface EDHOC-Exporter(label, length). Appendix C and D now uses the exporter interface.
- More information and examples on different ways to identify public keys. More security details regarding identities as suggested by University of Copenhagen.
- Updated CCDL definitions with .cbor and .cborseq
- Changes aad_i and exchange_hash definitions to make implementations more optimized
- The algorithm arrays are now defined as algs = alg / [ 2* alg ], an idea borrowed from draft-schaad-cose-x509
- Renamed session IDs to connection IDs to make the purpose clearer.
- More explanation and clarification on how error messages work and how they interact with lower layers as requested by Jim Schaad.
- Modified the error handling to allow truncation of the list of supported algoritms.
- IANA section to register a Content-Format
- Added an appendix shortly explaining CBOR, CDDL, and COSE to developers of EDHOC (as suggested by Klaus Hartke)
- Significantly expanded security considerations section, now divided in subsections.
- Expanded the message size appendix to also cover PSK and certificate. Compared to the TLS 1.3 handshake with TLS 1.3 the number of bytes in EDHOC is less than 1/3 when PSK	 authentication is used and less than 1/2 when RPK authentication is used
 		
 	                 PSK       RPK       x5t     x5chain	
 	   --------------------------------------------------------------------	
 	   message_1      47        44        44        44	
 	   message_2      49       125       131       121 + Certificate chain	
 	   message_3      12        86        92        82 + Certificate chain	
 	   --------------------------------------------------------------------	
 	   Total         108       255       267       247 + Certificate chains	
 		
 	                 Figure : Typical message sizes in bytes

Cheers,
John

On 2018-09-18, 13:15, "[email-masked]" <[email-masked]> wrote:

A new version of I-D, draft-selander-ace-cose-ecdhe-10.txt
has been successfully submitted by John Mattsson and posted to the
IETF repository.

Name:		draft-selander-ace-cose-ecdhe
Revision:	10
Title:		Ephemeral Diffie-Hellman Over COSE (EDHOC)
Document date:	2018-09-18
Group:		Individual Submission
Pages:		44
URL:            https://www.ietf.org/internet-drafts/draft-selander-ace-cose-ecdhe-10.txt
Status:         https://datatracker.ietf.org/doc/draft-selander-ace-cose-ecdhe/
Htmlized:       https://tools.ietf.org/html/draft-selander-ace-cose-ecdhe-10
Htmlized:       https://datatracker.ietf.org/doc/html/draft-selander-ace-cose-ecdhe
Diff:           https://www.ietf.org/rfcdiff?url2=draft-selander-ace-cose-ecdhe-10

Abstract:
   This document specifies Ephemeral Diffie-Hellman Over COSE (EDHOC), a
   very compact, and lightweight authenticated Diffie-Hellman key
   exchange with ephemeral keys that can be used over any layer.  EDHOC
   provides mutual authentication, perfect forward secrecy, and identity
   protection.  EDHOC uses CBOR and COSE, allowing reuse of existing
   libraries.

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