Subject: WG Action: Rechartered Transport Layer Security (tls)

From: The IESG <[email-masked]>
Date: Fri, 07 Feb 2014 10:02:58 -0800

The Transport Layer Security (tls) working group in the Security Area of
the IETF has been rechartered. For additional information please contact
the Area Directors or the WG Chairs.

Transport Layer Security (tls)
------------------------------------------------
Current Status: Active WG

Chairs:
  Eric Rescorla <[email-masked]>
  Joseph Salowey <[email-masked]>
  Eric Rescorla <[email-masked]>

Technical advisors:
  Allison Mankin <[email-masked]>

Assigned Area Director:
  Sean Turner <[email-masked]>

Mailing list
  Address: [email-masked]
  To Subscribe: https://www.ietf.org/mailman/listinfo/tls
  Archive: http://www.ietf.org/mail-archive/web/tls/

Charter:

The TLS (Transport Layer Security) working group was
established in 1996 to standardize a 'transport layer'
security protocol.  The basis for the work was SSL
(Secure Socket Layer) v3.0.  The TLS working group has
completed a series of specifications that describe the
TLS protocol v1.0, v1.1, and v1.2 and DTLS
(Datagram TLS) v1.2 as well as extensions to the
protocols and ciphersuites.

The primary purpose of the working group is to develop
(D)TLS v1.3.  Some of the main design goals are as follows,
in no particular order:

o Develop a mode that encrypts as much of the handshake as
is possible to reduce the amount of observable data to
both passive and active attackers.

o Develop modes to reduce handshake latency, which primarily
support HTTP-based applications, aiming for one roundtrip
for a full handshake and one or zero roundtrip for repeated
handshakes.   The aim is also to maintain current security 
features.

o Update record payload protection cryptographic
mechanisms and algorithms to address known weaknesses
in the CBC block cipher modes and to replace RC4.

o Reevaluate handshake contents, e.g.,: Is time needed in
client hello?  Should signature in server key exchange
cover entire handshake?  Are bigger randoms required?
Should there be distinct cipher list for each version?  Are
additional mechanisms needed to prevent version rollback
needed?

o The WG will consider the privacy implications of
TLS1.3 and where possible (balancing with other requirements)
will aim to make TLS1.3 more privacy-friendly, e.g. via more
consistent application traffic padding, more considered use
of long term identifying values, etc.

A secondary purpose is to maintain previous version of
the (D)TLS protocols as well as to specify the use of
(D)TLS, recommendations for use of (D)TLS, extensions to
(D)TLS, and cipher suites.  However, changes or additions
to older versions of (D)TLS whether via extensions or
ciphersuites are discouraged and require significant
justification to be taken on as work items.  

With these objectives in mind, the TLS WG will also place a priority
in minimizing gratuitous changes to TLS.

Milestones:
  Jan 2014 - CBC Fixes to IESG
  May 2014 - RC4 replacement to IESG
  Nov 2014 - (D)TLS 1.3 to IESG