Keeping Data Secret Under Full Compromise Using Porter Devices
The authors address the problem of confidentiality in scenarios where the attacker is not only able to observe the communication between principals, but can also fully compromise the communicating parties (their devices, not only their long-term secrets) after the confidential data has been exchanged. They formalize this problem and explore solutions that provide confidentiality after the full compromise of devices and user passwords. They propose two new solutions that use explicit key deletion and forward-secret protocols combined with key storage on porter devices. The solutions provide the users with control over their privacy. They analyze the proposed solutions using an automatic verification tool.