10 papers · 1 filter
Trapdoor Functions with Secure Key Leasing and Copy Protection
Fuyuki Kitagawa, Ryo Nishimaki, Yuki Shirakawa +1
Inspired by the no-cloning theorem in quantum theory, a variety of quantum cryptographic primitives with unclonable functionalities, such as secure key leasing and copy protection,…
Towards the Impossibility of Imperfectly Complete Key Agreement in the QROM
Fuyuki Kitagawa, Ryo Nishimaki, Agi Villanyi +1
We make progress towards the impossibility of imperfectly complete quantum-computation, classical-communication (QCCC) key agreement by constructing the first unconditional attacks…
Separating Non-Interactive Classical Verification of Quantum Computation from Falsifiable Assumptions
Mohammed Barhoush, Tomoyuki Morimae, Ryo Nishimaki +1
Mahadev [SIAM J. Comput. 2022] introduced the first protocol for classical verification of quantum computation based on the Learning-with-Errors (LWE) assumption, achieving a 4-mes…
Multi-Copy Security in Unclonable Cryptography
Alper Çakan, Vipul Goyal, Fuyuki Kitagawa +2
Unclonable cryptography leverages the quantum no-cloning principle to copy-protect cryptographic functionalities. While most existing works address the basic single-copy security,…
Collusion-Resistant Quantum Secure Key Leasing Beyond Decryption
Fuyuki Kitagawa, Ryo Nishimaki, Nikhil Pappu
Secure key leasing (SKL) enables the holder of a secret key for a cryptographic function to temporarily lease the key using quantum information. Later, the recipient can produce a…
MicroCrypt Assumptions with Quantum Input Sampling and Pseudodeterminism: Constructions and Separations
Mohammed Barhoush, Ryo Nishimaki, Takashi Yamakawa
We investigate two natural relaxations of quantum cryptographic primitives. The first involves quantum input sampling, where inputs are generated by a quantum algorithm rather than…