Systems and methods for cryptographically processing data as a function of
a Cassels-Tate pairing are described. In one aspect, a Shafarevich-Tate
group is generated from a cohomology group. A Cassels-Tate pairing is
determined as a function of elements of the Shafarevich-Tate group. Data
is then cryptographically processed as a function of the Cassels-Tate
pairing.