Architecture of The PRIVATGRAM Secure Corporate Messenger for Critical Infrastructure Based on X3DH And Double Ratchet Protocols
Abstract
The rapid development of mobile messaging applications has significantly transformed internal communications within banks, government institutions, and other critical information infrastructure (CII) facilities. However, the use of foreign public communication platforms creates risks associated with confidential data leakage, metadata exposure, dependence on foreign infrastructure, and insufficient administrative control.
This paper proposes the architecture of PRIVATGRAM, a sovereign secure corporate messenger designed for the banking sector and critical infrastructure organizations. The proposed architecture is based on a modified Signal-class security model and integrates the X3DH key agreement protocol and the Double Ratchet algorithm. Unlike consumer-oriented solutions, PRIVATGRAM implements centralized administration, device-level session isolation, persistent ratchet-state storage, role-based access control, secure session recovery mechanisms, and sovereign on-premises deployment capabilities.
The research demonstrates that sovereign secure messaging systems can significantly reduce cybersecurity risks, enhance digital sovereignty, and ensure compliance with the operational requirements of the banking sector and critical infrastructure facilities.
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References
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