Zero-Knowledge Differential Isotopic Comparison of Special Nuclear Materials

Zero-knowledge proofs are mathematical cryptographic methods to demonstrate the validity of a statement while providing no further information related to the statement itself. The possibility of using such proofs to process sensitive physical data without ever acquiring sensitive information has gained attention for its potential application to nuclear warhead or subassembly inspection. Recently, we have provided experimental evidence that measuring sensitive data is not required to perform comparisons of physical properties, in particular opacity to 14 MeV neutrons. Here, we report on the development of a non-electronic active neutron interrogation technique using superheated emulsion detectors to discriminate special nuclear materials of identical geometry but different isotopic composition, without learning what these properties are.