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Graphical Methods in Device-Independent Quantum Cryptography



Spencer J. Breiner, Carl A. Miller, Neil J. Ross


We introduce a framework for providing graphical security proofs for quantum cryptography using the methods of categorical quantum mechanics. We are optimistic that this approach will make some of the highly complex proofs in quantum cryptography more accessible, facilitate the discovery of new proofs, and enable automated proof verification. As an example of our framework, we reprove a recent result from device-independent quantum cryptography: any linear randomness expansion protocol can be converted into an unbounded randomness expansion protocol. We give a graphical exposition of a proof of this result and implement parts of it in the Globular proof assistant.


quantum cryptography, automated proof-checking, random number generation, category theory


Breiner, S. , Miller, C. and Ross, N. (2019), Graphical Methods in Device-Independent Quantum Cryptography, Quantum, [online], (Accessed February 28, 2024)
Created May 27, 2019, Updated May 31, 2019