PG-RSCA-2526-SignalAttack/PG Meeting 28.05.25.md

PG Meeting 28.05.25

ToDo:

• Add other device from already existing user and look what happens

• Traffic analysis of rekeying (group and single device and adding additional device)

Marvin: - recompile Signal for more logging

Leander: - Looking into the rekeying mechanism exchange from outside

Maurice: - Add a second device for the same user to a group

Ideas for backchannels:

• Rekeying on leaving or entering a group ?
• Rekeying on new device of an already participant in the group (active)
• Getting status info (passive)
• Typing... notification as timing backchannel (passive)

Tooling:

• SSLKEYLOGFILE env to decrypt server communication (possible)
• Self compile Signal app and add logging after message decryption

Ideas:

• Is there a RTT in calls before ringing (handshake with RTT ?)