8 papers
More is Less:Optimal Security for Haar Quantum Money and More
Zihan Hao, Xingjian Li, Qipeng Liu +1
Quantum cryptography leverages unclonability to enable a wide range of cryptographic applications that are impossible classically, such as digital currency protected against counte…
Impossibility of Perfectly Complete Many-Round Key Agreement in the QROM
Longcheng Li, Qian Li, Xingjian Li +1
This paper proves that it is impossible to construct perfectly complete quantum key agreement protocols (QKA) from quantumly secure one-way functions (OWFs) in a black-box manner.…
Single-sideband-interference twin-field quantum key distribution without global phase locking
Xingjian Li, Bingkun Wang, Jianyong Hu +10
Twin-field quantum key distribution (TF QKD) can overcome the fundamental rate loss limit of repeaterless quantum links, but its practical deployment has long been hindered by the…
Cryptomania v.s. Minicrypt in a Quantum World
Longcheng Li, Qian Li, Xingjian Li +1
We prove that it is impossible to construct perfect-complete quantum public-key encryption (QPKE) with classical keys from quantumly secure one-way functions (OWFs) in a black-box…
Transform Arbitrary Good Quantum LDPC Codes into Good Geometrically Local Codes in Any Dimension
Xingjian Li, Ting-Chun Lin, Min-Hsiu Hsieh
Geometrically local quantum codes, comprised of qubits and checks embedded in with local check operators, have been a subject of significant interest. A key challeng…
How (not) to Build Quantum PKE in Minicrypt
Longcheng Li, Qian Li, Xingjian Li +1
The seminal work by Impagliazzo and Rudich (STOC'89) demonstrated the impossibility of constructing classical public key encryption (PKE) from one-way functions (OWF) in a black-bo…
Classical vs Quantum Advice and Proofs under Classically-Accessible Oracle
Xingjian Li, Qipeng Liu, Angelos Pelecanos +1
It is a long-standing open question to construct a classical oracle relative to which BQP/qpoly BQP/poly or QMA QCMA. In this paper, we construct classically-accessib…
On the Feasibility of Unclonable Encryption, and More
Prabhanjan Ananth, Fatih Kaleoglu, Xingjian Li +2
Unclonable encryption, first introduced by Broadbent and Lord (TQC'20), is a one-time encryption scheme with the following security guarantee: any non-local adversary (A, B, C) can…