Toxcore is a peer-to-peer networking library that implements a decentralized communication protocol for secure messaging and media calls without the use of central servers. It provides a core engine for establishing direct encrypted connections between devices using a public-key identity system where unique identifiers serve as both addresses and authentication keys.
The project features a decentralized network architecture that utilizes a distributed hash table for peer discovery and Kademlia-based routing to locate participants. To maintain connectivity across restrictive network environments, it employs UDP hole punching for NAT traversal and multi-hop relay routing with TCP fallback to bypass firewalls.
The library covers a broad capability surface including end-to-end encrypted data transmission for text and files, as well as real-time encrypted voice and video calling. It also manages the generation of cryptographic identities and the registration of trusted communication partners.