DICE IETF-89 Minutes

Note takers - Akbar, Corinna (Edits from Zach)

1) Intro

- Zach is chairing this session alone as Dorothy could not make it.

Introduction:
	- repeating scope of WG
	- repeating Goals and Milestones
	- May need to adujst WG deliverable dates as we get closer to the scheduled dates


2) DTLS Profile draft [Klaus Hartke, Hannes Tschofenig]  
draft-hartke-dice-profile-03


Communication Model
- Hannes - Draft covers unicast (as multicast is covered in another document) and IoT device to server (with server being unconstrained) 
- Carsten - In CoAP, the server is often most resource constrained          
- Carsten - We have to have a precise definition of client and server
- Zach: Terms from DTLS can be applied here not the ones from CoRE. This must be clarified in the next draft version. P2P communication is out of scope here.
- Hannes - Will add some simple examples/use cases to illustrate
- Matthias - Agrees with Carsten's concern where server is often constrained
- Göran? (Ericsson) - Should cover cases where all the nodes can be constrained
- Carsten - We have solutions. See what we offer. Look on life time of session.
-? - We should cover constrained servers that may be interacting with many clients.  This may greatly impact the server
- D. Robin - everything has to be peer-to-peer connected. Think about a knocking message that is unsecured, just to initiate the communication
- Robert Cragie - Think of network authentication
- Subhir - Do you consider a relay in this model?
- Hannes - I didn't think it mattered, but if you do think it matters please call it out
- Zach - Specifying DTLS relay is out of sope of the WG

CoAP vs. non-CoAP
- Hannes - Work was heavily influenced by CoAP
- Long discussion by several speakers and Hannes about what cipher suites to use and how to align it with various protocols.  Hannes started off by looking at what CoAP supported
- Hannes - Depending on the used communication type implementations exist that also include special support for this.

PSK Ciphersuite & PFS
- Carsten - We want get rid of UTF identifier. It is better to send binary data

Raw Public Key Mode
- Inherited from CoAP
- No questions/comments from audience

Certifcate Mode
- B. Nixon - What about capabilities available with DANE?  Which allows certificate to be registered in DNS and allows fast updates
- Hannes- Good point but I haven't looked into this yet

Zach: Good shape. Some open issues. Please, go on the mailing list and ask your comments/questions there. WG Document adoption scheduled soon


3) Multicast draft [Sandeep Kumar]                              
draft-keoh-dice-multicast-security-05

- Sandeep - Goes over motivating use cases and requirements
- Sandeep - Goes over proposed solution (use DTLS rcord layer to protect CoAP group comm messages; out of band setup of Group Security Association)
- Sandeep - DTLS record layer adaptation, and DTLS recrd layer processing remains nearly unchanged
- Stephen Farrell - Just skip to open questions as we already discussed this previously

- Zach - We are chartered for this approach as described by Sandeep.  Now we have suggestions by Mike and others to go beyond this solution which is a good discussion.  Like requiring source authentication.  As a WG do we need to support this?
- Eker - You should abandon DTLS record layer to support multicast [if you want to support source authentication].  Source authentication is really required for many IoT use cases.
- Zach - Should we try to extend CoAP to do this (instead of DTLS record layer)?
- Carsten - Want to avoid complicated re-design.  Don't know what component we could use for source authentication?
- MikeStJohn - Public key integrity can be done in several ways
- Eker - There may be problems with this depending on what layers you are doing this

- Zach - We have a solution that fits the charter but may need to support source authenticaton.  We need to have complementary drafts looking at alternate solutions
- Stepehen Farrell - Sounds like a potentially huge increase in scope
- Zach - Yes, we need if weto decide  really want to expand the scope
- Stephen Farrell - So we should hold this draft until the complementary drafts are written
- Zach - Yes



4) Next Steps [Chairs]                    
- WG adoption call for draft-hartke-dice-profile-03
- Strawman ID needed to explore alternative CoAP multicast authentication