Hop-by-hop SRTP¶
Crypto - srtp-hop-by-hop
CRY-03 - status: draft - audio, video, group
Relay-facing SRTP layer protecting each client↔relay hop, independent of the end-to-end layer.
- Client↔relay media MUST use a hop-by-hop SRTP context independent of the end-to-end context.
- Suite:
AES_CM_128_HMAC_SHA1_80. - The relay supplies 30 bytes of
masterKey || masterSaltdirectly. Hop-by-hop keying MUST skip the WAHKDF layer and apply only the RFC 3711 expansion (see srtp-master-key).
Parent: srtp-master-key
Requires: srtp-master-key
Breakdown: srtp-e2e, video-packetization, relay-candidates, rtcp, rtp-framing, warp
Implemented by
| Flavor | Status | Source | Notes |
|---|---|---|---|
whatsapp-rust |
working | history - blame - commits 674e851 |
— |
zapo-caller |
working | — | — |
Annotation wacrg:CRY-03 — a flavor marks its implementation site in source with this comment; a script clones the source, finds it, and attaches the commit blame/permalink.
Contributors
| Contributor | Role |
|---|---|
 Rajeh Taher |
wrote initial spec |
protocol history / diff - blame
Changelog¶
- 2026-06-21 — Initial spec entry.