Preserving Privacy: Borromean Ring Signing

I am a great fan of the work of Greg Maxwell, so here’s one of his classics [here]:

A Borromean ring, in maths, is defined as three closed curves that cannot be separated from each other but can be unknotted when one of the rings is cut or removed.

Ring signatures

And so there has been a leak of information at the White House. Donald Trump calls in his Cyber Security leads, and tells them, “I know one of you leaked the information, but I can’t tell which one”. How can Donald tell that one of his leads has leaked the information, but not know which one? Well, this can be achieved with a ring signature, and which provides anonymity, unforgivably and collusion resistance.

A ring signature is a digital signature that is created by a member of a group that each have their own keys. It is then not possible to determine the person in the group who has created the signature. The method was initially created by Ron Rivest, Adi Shamir, and Yael Tauman in 2001…