Version 15 (modified by kristof.teichel@…, 6 years ago) (diff)


Network Time Security WGLC Design Team Discussions

Link to the agenda document (everyone may comment, only Dieter and Kristof may edit at the moment):

Identified Agenda Items for the Design Team

  • Top Priority:
    1. IP fragmentation of certificate-carrying messages during key exchange
    2. Key exchange protocol: do fewer exchanges?
  • High Priority:
    1. Key exchange protocol: have fewer cryptographic operations?
    2. Key exchange protocol: what about two-way authentication?
    3. Discussion about Chicken-and-Egg Problem
    4. Improve Handling of Cipher Suites
  • Medium Priority
    1. Improve Treatment of Peer Mode
    2. Symmetry of Message Sizes “time_request” and “time_response”
    3. Use of Initial (Unsecured) Timestamps
    4. Seed Refresh: Should this Be Mentioned
    5. Discussion about Different Security Approaches
    6. MAC-Algorithm instead of Hash (for HMAC) Algorithm


First (teleconference) meeting likely on Monday, 25 April, 15:30 UTC; some form of minutes will be made available.

April 25th (Monday)

  • Platform: Adobe Connect. Severe connection issues for Kristof.
  • Attending: Danny, Dieter, Harlan, Karen, Kristof, Miroslav, Sharon.
  • Meeting Agenda:
    • Introductions & organizational issues (minute taking)
    • Discussion on correctness & completeness of the team agenda list in the document linked above
    • Discussion on priorities of items (especially "must have" vs. "nice to have")
    • Optional: Start of discussion on high-priority items
    • Set date for next meeting
  • Additional minutes:
    • Group: Declaring certificate exchange out of scope is bad idea
    • Group: (D)TLS seems promising option
    • Sharon: what is design goal behind custom key exchange (KE)?
    • Miroslav: solve fragmentation by limiting to one cert per exchange?
    • Karen: DTLS / IPsec people should be involved at some point

May 2nd (Monday)

  • Platform: Adobe Connect. Issue with connectivity between dial-in and PC connections.
  • Attending: Dieter, Harlan, Karen, Kristof, Miroslav, Sharon.
  • Meeting Agenda:
    • Organizational issues
      • Minute taking
      • Date for next meeting
    • Discussion for item "IP fragmentation" (~10-15 min. each):
      • List of requirements by Miroslav
      • Option "Self-management" (NTS splits extension field data)
      • Option "External channel" (TCP/(D)TLS/HTTPS/...)
    • Flesh out item "Two-way authentication" (~5 min.)
    • Discussion of item "Peer mode" (~5 min.)
    • General discussion
  • Additional minutes:
    • Next meeting same time following week. Karen agrees to provide better meeting room.
    • Group: more discussion on DTLS
    • Sharon: should ask DTLS folks specifically. Agrees to contact someone.
    • Miroslav: what about peer mode (expected to be dealt with alreday)
    • Kristof: peer mode via old symmetric approach?
    • Group: discussion about merits/disadvantages of two-way authentication

May 9th (Monday)

  • Platform: WebEx? (room supplied by Karen).
  • Attending: Dieter, Harlan, Kristof, Miroslav, Sharon
  • Minutes:
    • Group: More discussion on mutual authentication
    • Harlan: needed for peer mode and also mode 6 NTP packets
    • Group: perhaps specify two KE procedures, one which sticks to UDP 123 etc., another which is fast

May 17th (Tuesday)

  • Platform: WebEx? (room supplied by Karen).
  • Attending: Harlan, Kristof, Miroslav

Week of May 22nd

-Meeting skipped-

May 31st (Tuesday)

  • Platform: WebEx? (room supplied by Karen).
  • Attending: Danny, Dieter, Harlan, Karen, Kristof, Miroslav, Sharon
  • Meeting Agenda:
    • Changes by Dieter and Kristof (DTLS options)
  • Additional minutes:
    • Group: Discussion on unauthenticated timing data
    • Sharon: is in favor of "MUST NOT" language
    • Kristof: would like to treat this in section "NTS assumptions about initial timing quality"
    • Group: eliminated some options for the fragmentation issue
    • Upcoming meeting cancelled in favor of only NTPWG call (Thursday, June 9th). After that, Design team calls can be moved back to Mondays, 15:30 UTC