Pica Pica is a project designed to create and support a distributed, decentralized, and secure instant messaging system. The Pica Pica network consists of nodes and clients. Nodes are hosted by volunteers on their computers, and they connect to each other to exchange information about other nodes and online clients, while transferring encrypted data between clients.

All data transferred between clients is protected by end-to-end encryption using the TLS 1.2 protocol. User accounts are based on self-signed X.509 certificates, and users are identified by the unique SHA-224 hash of these certificates. A Pica Pica ID is a Base64-encoded representation of this SHA-224 hash, which appears as follows: m+2TC+ZYDx0crQZK1p97cuAIp1rH5i1SLe6EtA==.

This cryptic identifier is necessary because there is no central authority to ensure the uniqueness of human-readable identifiers.