Siper

Siper is an end-to-end encrypted messaging and conferencing platform that runs on the customer's own infrastructure. Built from scratch in Java and Swift on the Signal protocol, with Android, iOS, Windows, macOS and Linux (Pardus-compatible) clients connected to the same backend.

Scope

• Signal protocol messaging: text, files, voice and video calls
• Custom backend built in Java on Openfire, with corporate directory integration
• Native Android (Java) and iOS (Swift) apps, plus a TypeScript web client
• Windows, macOS and Linux (Pardus-compatible) desktop clients
• Two-factor authentication and AI-assisted attack detection
• ISO/IEC 27001 management system and independent UITSEC penetration tests

Approach

Encryption keys stay on the device; the server cannot read message content. All five platforms share the same protocol layer and data model, so behaviour stays consistent across clients. Directory integration and two-factor authentication were designed as part of the rollout.

Deployment

Siper is installed on servers dedicated to the institution; messages, files and call records stay on its own infrastructure and never leave for overseas cloud services.

My role

Development of the entire platform: backend, mobile and desktop clients, and the information security management system.