IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-021 Disclosing Secure RTP (SRTP) Session Keys draft-wing-sipping-srtp-key-02 Dan Wing, Francois Audet, Steffen Fries, Hannes Tschofenig,

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-022 Scenario “This call may be recorded for quality purposes” Businesses need to record their employee’s phone calls –Banks, stockbrokers –Catalog ordering companies –Travel agencies, hotel reservations –Regulatory requirements United States: Sarbanes-Oxley Act

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-023 Meeting Requirement Today Today: Recording is easy –Media is RTP (unencrypted) –Signaling is SIP (unencrypted) IP network IP phones VoIP headsets VoIP softphones Caller Recording Device

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-024 Meeting Requirement Tomorrow Tomorrow: Recording is not possible –Media is SRTP –SIP signaling might also be encrypted

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-025 Requirements Completely separate from SRTP keying technique –Work with every SRTP keying mechanism Allow SIP signaling to be encrypted Allow SDP to be encrypted Endpoint MUST cooperate in key disclosure –Allows user to be reminded of SRTP key disclosure –Allows user to authorize the recording, per call Do not require a B2BUA Allow recording all calls or selective calls –User decides / call processing system decides

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-026 Proposed Mechanism

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-027 Proposed Mechanism 1.Endpoints perform normal SRTP keying 2.Endpoint uses public key of recording device to encrypt the two SRTP session keys (transmit key and receive key) 3.Endpoint sends that encrypted information to its SIP proxy 4.SIP proxy routes the message to the recording device 5.Recording device decrypts message, and now has SRTP session keys

IETF70, Vancouver, December 2007draft-wing-sipping-srtp-key-028 Questions draft-wing-sipping-srtp-key-02 Dan Wing, Francois Audet, Steffen Fries, Hannes Tschofenig,