A New Definition of Semantic Security for Public-Key Encryption Schemes (Foundations of Computer Science)

Kaibin Huang, Raylin Tso, Yu‐Chi Chen

Manuel Barbosa, Pooya Farshim

Chong Xiang, Li Yang

We investigate the definition of security for encryption scheme in quantum context. We systematically define the indistinguishability and semantic security for quantum public-key and private-key encryption schemes, and for computational security, physical security and information-theoretic security. Based on our definition, we present a necessary and sufficient condition that leads to information-theoretic indistinguishability for quantum encryption scheme. The equivalence between the indistinguishability and semantic security of quantum encryption scheme is also proved.

Carsten Rudolph

Michael St-Jules

To the field of cryptography, quantum mechanics is a game changer. The exploitation of quantum mechanical properties through the manipulation of quantum information, the information encoded in the state of quantum systems, would allow many protocols in use today to be broken as well as lead to the expansion of cryptography to new protocols. In this thesis, quantum encryption, i.e. encryption schemes for quantum data, is defined, along with several definitions of security, broadly divisible into semantic security and ciphertext indistinguishability, which are proven equivalent, in analogy to the foundational result by Goldwasser and Micali. Private- and public-key quantum encryption schemes are also constructed from quantum-secure cryptographic primitives, and their security is proven. Most of the results are in the joint paper Computational Security of Quantum Encryption, to appear in the 9th International Conference on Information Theoretic Security (ICITS2016).

Kazukuni Kobara