Compeer: Decentralised P2P Secure Messaging

Centralised messaging infrastructure is a single point of failure, interception, and denial of service. In tactical and operational contexts, an adversary who can take down or monitor a central server can silence communications across an entire network. Existing encrypted messaging applications address confidentiality but retain central dependency for peer discovery, message routing, and key exchange, leaving them vulnerable to infrastructure-targeted attacks.

Built a fully decentralised peer-to-peer messaging system where no central server exists at any layer of the architecture. Peers discover each other through a distributed gossip mechanism that requires no pre-existing directory. All messages are encrypted end-to-end with forward secrecy before leaving the originating device. The system maintains communication under network partition conditions and is resilient to selective node failures without requiring reconnection to a central authority.

Peers locate each other without consulting a central registry. The discovery mechanism operates across local networks and wide-area topologies using gossip-based announcement that degrades gracefully when portions of the network are unavailable. New peers joining a network segment find existing participants within seconds without pre-configuration.

Every message is encrypted between originating and recipient peers using a key exchange that produces a unique session key per conversation. Even if a session key is later extracted from a device, past messages cannot be decrypted: each key is discarded after use. The system implements forward secrecy at the session and message level.

When a direct path between two peers is unavailable, the system routes delivery through intermediate peers in the mesh. Messages are queued locally when no path exists and retried as connectivity restores. The routing layer detects network partitions and adapts path selection without requiring a global view of network state.