Practically-exploitable Cryptographic Vulnerabilities in Matrix

We report several practically-exploitable cryptographic vulnerabilities in the Matrix standard for federated realtime communication and its flagship client and prototype implementation, Element. These, together, invalidate the confidentiality and authentication guarantees claimed by Matrix against a malicious server. This is despite Matrix’ cryptographic routines being constructed from well-known and studied cryptographic building blocks...
By: Martin Albrecht , Sofía Celi , Benjamin Dowling , Dan Jones
Full Abstract and Presentation Materials:
www.blackhat.com/eu-22/briefi...