Discord DAVE aka securing messages as top priority.

Discord’s introduction of the DAVE protocol is a significant step towards enhancing privacy for its users by offering end-to-end encryption (E2EE) for audio and video calls. While this new feature improves security in voice and video chats across DMs, group chats, and live streams, Discord notably leaves messages unencrypted to allow for moderation, which might seem controversial given today’s focus on user privacy.

The DAVE protocol, which stands for "Discord’s Audio and Video End-to-End Encryption," integrates several key technical innovations. It uses WebRTC encoded transforms for encrypting media frames and Message Layer Security (MLS) for group key exchange (GKE). In practical terms, this means each media frame—whether audio or video—gets encrypted with a symmetric key unique to the sender and known only to participants of the call. This ensures that outsiders, including Discord, cannot decrypt the media. As Discord noted, “each frame is encrypted or decrypted with a per-sender symmetric key,” thus limiting access to authorized participants only.

Another important feature is how MLS manages user transitions in and out of calls. According to Discord, "new participants cannot decrypt media sent before they joined, and leaving members can’t access future communications," which adds an extra layer of privacy by preventing retroactive decryption of past conversations.

On the surface, this is a solid enhancement for privacy-conscious users. However, Discord’s decision to keep messages unencrypted to allow content moderation raises questions about the completeness of its privacy commitments. The company explains this by stating, “when we consider adding new privacy features like E2EE A/V, we do not do so in isolation from safety,” emphasizing that the balance between privacy and safety is a crucial factor in its policies.

DAVE’s public auditability, reviewed by Trail of Bits, adds credibility to its technical security claims, giving the community an opportunity to scrutinize its implementation. Unlike end-to-end encrypted calls, however, messages will continue to be subject to Discord's content moderation, which some might argue undermines the overall push toward privacy.

The underlying technology ensures that even Discord’s Selective Forwarding Unit (SFU), which processes all packets for the call, cannot decrypt the data being transmitted. According to Discord, “while the SFU still processes all packets for the call, audio or video data inside each packet is end-to-end encrypted and undecryptable by the SFU.”

In the broader context of tech platforms, Discord’s move comes at a time when other services like Meta and Google’s RCS are also exploring stronger encryption options. This shows a growing recognition of the need for better data privacy. However, the balance between privacy and content moderation, especially for platforms hosting large, diverse communities, remains a complicated issue.

As someone who values both privacy and safety, I think this move is a promising start, but the fact that messages remain unencrypted somewhat limits the effectiveness of the encryption. Nevertheless, it’s clear that Discord is aligning itself with industry trends to improve user security, though time will tell how well this balance holds.

The Hacker News (2024). Discord Introduces DAVE Protocol for End-to-End Encryption in Audio and Video Calls. [online] The Hacker News. Available at: https://thehackernews.com/2024/09/discord-introduces-dave-protocol-for.html [Accessed 24 Sep. 2024].