European governments are transitioning from encrypted messaging applications like Signal and WhatsApp to sovereign Matrix-based solutions. This shift follows successful phishing campaigns, primarily attributed to Russian intelligence services, exploiting Signal's linked devices feature to gain persistent access to political communications. While Signal was initially recommended for external communications, scope creep led to its widespread use for sensitive statecraft discussions. Matrix-based systems offer advantages including federated architecture, government-controlled identity platforms, and customizable data retention policies. However, these homegrown solutions introduce new security vulnerabilities and implementation challenges. The walled-garden nature of current sovereign systems limits their utility for international diplomacy, suggesting Signal will continue to be used for communications with external parties despite the security concerns.