Spy agency’s maths problem used to protect Twitter users

Twitter has used an “impossible” mathematical problem first discovered by intelligence organisation GCHQ to protect its users from electronic snooping.

The company said that “perfect forward secrecy” (PFS) was now live on all its services, drastically increasing the effort required to intercept its traffic.

Jim Killock, director of the Open Rights Group, said it was a “policy move” driven by revelations about mass surveillance by the British security agency GCHQ and the American National Security Agency.