Quantum Identity

Jessica Pointing, Oded Padon, Zhihao Jia +4 more

Abstract Existing quantum compilers focus on mapping a logical quantum circuit to a quantum device and its native quantum gates. Only simple circuit identities are used to optimize the quantum circuit during the compilation process. This approach misses more complex circuit identities, which could be used to optimize the quantum circuit further. We propose Quanto, the first quantum optimizer that automatically generates circuit identities. Quanto takes as input a gate set and generates provably correct circuit identities for the gate set. Quanto’s automatic generation of circuit identities includes single-qubit and two-qubit gates, which leads to a new database of circuit identities, some of which are novel to the best of our knowledge. In addition to the generation of new circuit identities, Quanto’s optimizer applies such circuit identities to quantum circuits and finds optimized quantum circuits that have not been discovered by other quantum compilers, including IBM Qiskit and Cambridge Quantum Computing Tket. Quanto’s database of circuit identities could be applied to improve existing quantum compilers and Quanto can be used to generate identity databases for new gate sets.

Peter D. Pešić

Peter D. Pešić

Ziyuan Liu, Yi‐Fan Tseng, Raylin Tso +2 more

Abstract Identity‐based encryption (IBE), introduced by Shamir, eliminates the need for public‐key infrastructure. The sender can simply encrypt a message by using the recipient's identity (such as email or IP address) without needing to look up the public key. In particular, when ciphertexts of an IBE do not reveal recipient's identity, this scheme is known as an anonymous IBE scheme. Recently, Blazy et al. (ARES '19) analysed the trade‐off between public safety and unconditional privacy in anonymous IBE and introduced a new notion that incorporates traceability into anonymous IBE, called anonymous IBE with traceable identities (AIBET). However, their construction is based on the discrete logarithm assumption, which is insecure in the quantum era. In this paper, we first formalize the consistency of tracing key of the AIBET scheme to ensure that a ciphertext cannot be traced with the use of wrong tracing keys. Subsequently, we present a generic formulation concept that can be used to transform structure‐specific lattice‐based anonymous IBE schemes into an AIBET. Finally, we apply this concept to Katsumata and Yamada's compact anonymous IBE scheme (Asiacrypt '16) to obtain the first quantum‐resistant AIBET scheme that is adaptively secure under the ring learning with errors assumption without random oracle.

Xing-Fu Wang, Shi‐Pu Gu, Yu‐Bo Sheng +1 more

Abstract A successful implementation of any secure communication protocols requires the identity authentication as a prerequisite. Quantum identity authentication (QIA) can ensure the unconditional security of identity code. In this paper, we propose a multi-party simultaneous quantum identity authentication (MSQIA) protocol based on the Greenberger-Horne-Zeilinger (GHZ) state. In the protocol, N certified users can directly send their identity codes to the authenticator Alice simultaneously through quantum channels without classical communication, which enables Alice to authenticate their identity at the same time. Our protocol only requires Alice to perform the single-photon measurement. In theory, this protocol is unconditionally secure and one pair of ( N + 1)-photon GHZ state can transmit N bits of identity codes. Our MSQIA protocol has application potential in the quantum communication field in the near future.

Сыч Денис Васильевич, Gerd Leuchs