This Project will investigate the security of a new block cipher first proposed by the Applicants and analyzed using theoretical physics techniques. This new block cipher: (i) is inspired by quantum circuit scramblers but implemented classically using reversible computing, (ii) is expected to be immune to quantum attacks, and (iii) enables direct computation on encrypted data in an alternative form to the long-researched yet still impractical homomorphic encryption. In order to fulfill this ability to encrypt Data in Use, the block cipher was designed to be the shortest possible, i.e., it has a minimal number of gates and circuit depth. As a first test of the cryptographic properties of the new block cipher, we will: (i) compare its randomness to that of the approved cryptographic algorithm, AES; (ii) check its performance against standard attacks; and (iii) engage with NIST cryptography experts and with the broader cryptography community for testing, benchmarking, and validation. Success in these activities will serve as a critical building block to a pioneering Encrypted Operator Computing (EOC) method being developed outside this proposed Project to protect Data In Use through encryption.
