1 Presentation_ID © 1998, Cisco Systems, Inc. SIP Security Status Michael Thomas

2 Presentation_ID © 1998, Cisco Systems, Inc. Current Status 2543bis leaves HTTP’isms, rest deprecated Many BOF’s, many different points of view Many common themes though One combination framework and requirements draft, and several drafts positing both point and generalized authentication schemes Many drafts are becoming more and more aware that there is the need for better security than an unauthenticated assertion isn’t adequate The workability of all of them rolling their own is nil Hercules should have it so easy

3 Presentation_ID © 1998, Cisco Systems, Inc. Proposal to Move Forward Separate out base level SIP “outside” attacks from “inside” attacks 2543bis provide a base mechanism for outside attacks: IPsec, TLS, return routability… Retain HTTP’isms for compatibility Allow 2543bis to advance without requirement for answers to harder-to-counter inside attacks Moratorium on inside attack crypto work Separate Standards Track draft for SIP security which addresses inside attacks and more Separate Informational Track Requirements draft

4 Presentation_ID © 1998, Cisco Systems, Inc. Proposed Work Create Requirements/Threats Draft Can reuse some of my draft as starting point Come to consensus on 2543bis base requirements Create a framework which can accommodate current popular authentication mechanisms X.509/PKI, Kerberos, Pre-shared, Radius/AAA… Focus on a simple initial authentication scheme Maybe pre-shared and/or NULL? Focus on two scenarios: UA-Proxy authentication (normal onramp challenge) Proxy-Proxy identity assertion (referrals/caller-id) Would be nice to align this with SRTP/SDP keying