Bringing DAVE to All Discord Platforms (opens in new tab)
Discord is making DAVE, its end-to-end encryption protocol for audio and video calls, mandatory across all platforms. Browser support required solving WebRTC compatibility issues, designing an efficient Web Worker architecture, and reusing proven C++ cryptography through WebAssembly. Clients without DAVE support will be unable to join calls starting March 1, 2026. ## DAVE Becomes the Standard - DAVE already protects tens of millions of Discord calls daily. - Support is expanding to browsers, consoles, and the Social SDK. - Non-DAVE clients and applications will lose access to Discord calls on March 1, 2026. ## Browser Support and Firefox Compatibility - Discord uses the WebRTC Encoded Transform API to encrypt audio and video inside the WebRTC pipeline. - Firefox initially failed during real calls because its encryption Web Worker received no media data. - Discord engineers identified a recursive mutex deadlock in Firefox’s `FrameTransformerProxy`, triggered when video arrived too early. - Mozilla merged Discord’s fix, which is available in Firefox 142.0—the minimum Firefox version required for DAVE. ## Web Workers and Call State - Dedicated Web Workers encrypt and decrypt media: - One worker handles call audio and camera video. - Separate workers handle screenshare and game-stream audio and video. - Each media stream has a unique SSRC, allowing workers to select the correct symmetric encryption key for each frame. - Workers retain only essential call state, including SSRC-to-user mappings and encryption keys. - The main thread manages WebRTC connections, participants, and media tracks. - MLS membership changes are also handled on the main thread, preventing encryption work from delaying users joining or leaving calls. - Cryptographic state changes are sent asynchronously to workers. ## WebAssembly for Proven Cryptography - Discord compiled its existing, battle-tested C++ DAVE implementation to WebAssembly. - Reusing the same implementation across platforms reduces platform-specific security and reliability risks. - DAVE must selectively encrypt media while preserving metadata needed by WebRTC packetization and depacketization. - Since encrypted output cannot be modified in transit, byte-level parsing must be precise. - WebAssembly provides near-native performance while avoiding a more error-prone JavaScript reimplementation. ## WebAssembly Versus Browser Cryptography APIs - WebAssembly introduces a small performance cost compared with native browser APIs such as `SubtleCrypto`. - Discord’s benchmarks evaluate this trade-off against the benefits of shared, mature cryptographic code. - The post indicates that WebAssembly remains practical because frame parsing and selective encryption are computationally complex, while the security and portability benefits outweigh the minor cryptographic overhead. Discord’s platform transition means developers maintaining Discord clients, integrations, or SDK-based applications should add DAVE support before March 1, 2026. Browser users must also use Firefox 142.0 or newer when connecting through Firefox.