== Network Time Security WGLC Design Team Discussions == Link to the agenda document (everyone may comment, only Dieter and Kristof may edit at the moment): https://docs.google.com/document/d/1CR5mFOP_WZ_FZDTf0IWsXLFOvhO4AXokZNvOb3PWI7E === 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: 3. Key exchange protocol: have fewer cryptographic operations? 4. Key exchange protocol: what about two-way authentication? 5. Discussion about Chicken-and-Egg Problem 6. Improve Handling of Cipher Suites * Medium Priority 7. Improve Treatment of Peer Mode 8. Symmetry of Message Sizes “time_request” and “time_response” 9. Use of Initial (Unsecured) Timestamps 10. Seed Refresh: Should this Be Mentioned 11. Discussion about Different Security Approaches 12. MAC-Algorithm instead of Hash (for HMAC) Algorithm === Meetings === 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