Protecting sensitive metadata so it can’t be used for surveillance
MIT researchers have designed a scalable system that secures the metadata — such as who’s corresponding and when — of millions of users in communications networks, to help protect the information against possible state-level surveillance. Data encryption schemes that protect the content of online communications are prevalent today. Apps like WhatsApp, for instance, use “end-to-end encryption” (E2EE), a scheme that ensures third-party eavesdroppers can’t read messages sent by end users. But most of those schemes overlook metadata, which contains information about who’s talking, when the messages are sent, the size of message, and other information. Many times, that’s all a government or other hacker needs to know to track an individual. This can be especially dangerous for, say, a government whistleblower or people living in oppressive regimes talking with journalists. Systems that fully protect user metadata with cryptographic privacy are complex, and they suffer scalability and speed issues that have so far limited...