Subject: Re: [TLS] New Version Notification for draft-mattsson-tls-ecdhe-psk-aead-00.txt

From: John Mattsson <[email-masked]>
Date: Mon, 29 Jun 2015 11:49:43 +0000

Hi,

We have submitted a new draft defining several new PSK_ECDHE cipher
suites. The cipher suites are all based on the Ephemeral Elliptic Curve
Diffie-Hellman with Pre-Shared Key (ECDHE_PSK) key exchange together with
the Authenticated Encryption with Associated Data (AEAD) algorithms
AES-GCM and AES-CCM. Pre-Shared-Key authentication is used in several
deployments, e.g. 3GPP and IoT.

Ericsson has recently proposed that 3GPP makes significant updates to the
3GPP profiles for TLS and DTLS. Among other things: Reference RFC7525 and
mandate implementation of TLS 1.2, DTLS 1.2, and
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (with P-256).

During this work we identified that the PSK cipher suites that we would
like to implement were not defined. We think that the natural choice for
anyone wanting PSK authentication should be to use ECDHE together with the
AEAD algorithms AES-GCM and AES-CCM.

Comments appreciated.

Cheers,
John

------------------------------------------------------------------
John Mattsson
MSc Engineering Physics, MSc Business Administration and Economics
Ericsson IETF Security Coordinator
Senior Researcher, Security

Ericsson AB                          Phone +46 10 71 43 501
Ericsson Research                    SMS/MMS +46 76 11 53 501
Färögatan 6                          john.mattsson at ericsson.com
SE-164 80 Stockholm, Sweden          www.ericsson.com
------------------------------------------------------------------

On 29/06/15 13:18, "[email-masked]" <[email-masked]>
wrote:

>
>A new version of I-D, draft-mattsson-tls-ecdhe-psk-aead-00.txt
>has been successfully submitted by John Mattsson and posted to the
>IETF repository.
>
>Name:		draft-mattsson-tls-ecdhe-psk-aead
>Revision:	00
>Title:		ECDHE_PSK with AES-GCM and AES-CCM Cipher Suites for Transport
>Layer Security (TLS)
>Document date:	2015-06-29
>Group:		Individual Submission
>Pages:		5
>URL:            
>https://www.ietf.org/internet-drafts/draft-mattsson-tls-ecdhe-psk-aead-00.
>txt
>Status:         
>https://datatracker.ietf.org/doc/draft-mattsson-tls-ecdhe-psk-aead/
>Htmlized:       
>https://tools.ietf.org/html/draft-mattsson-tls-ecdhe-psk-aead-00
>
>
>Abstract:
>   This memo defines several new cipher suites for the Transport Layer
>   Security (TLS) protocol.  The cipher suites are all based on the
>   Ephemeral Elliptic Curve Diffie-Hellman with Pre-Shared Key
>   (ECDHE_PSK) key exchange together with the Authenticated Encryption
>   with Associated Data (AEAD) algorithms AES-GCM and AES-CCM.  PSK
>   provides light and efficient authentication, ECDHE provides perfect
>   forward secrecy, and AES-GCM and AES-CCM provides encryption and
>   integrity protection.
>
>                  
>        
>
>
>Please note that it may take a couple of minutes from the time of
>submission
>until the htmlized version and diff are available at tools.ietf.org.
>
>The IETF Secretariat
>

---

From: Ilari Liusvaara <[email-masked]>
Date: Mon, 29 Jun 2015 14:57:08 +0300

> >Name:		draft-mattsson-tls-ecdhe-psk-aead

1) Searching existing ciphersuites, I think the names should be
TLS_ECDHE_PSK_WITH_*.

2) Also, might consider changing 256 bit minimum ECC size to 255,
since lower-security CFRG curve is 255 bits.

-Ilari