Ryo Nishimaki

Designated Verifier/Prover and Preprocessing NIZKs from Diffie-Hellman Assumptions.

2019 · IACR Cryptology ePrint Archive

In a non-interactive zero-knowledge (NIZK) proof, a prover can non-interactively convince a verifier of a statement without revealing any additional information. Thus far, numerous constructions of NIZKs have been provided in the common reference string …

Quantum Encryption with Certified Deletion, Revisited: Public Key, Attribute-Based, and Classical Communication

2021 · arXiv (Cornell University)

Broadbent and Islam (TCC '20) proposed a quantum cryptographic primitive called quantum encryption with certified deletion. In this primitive, a receiver in possession of a quantum ciphertext can generate a classical certificate that the encrypted …

Certified Everlasting Functional Encryption

2022 · arXiv (Cornell University)

Computational security in cryptography has a risk that computational assumptions underlying the security are broken in the future. One solution is to construct information-theoretically-secure protocols, but many cryptographic primitives are known to be impossible (or …

Certified Everlasting Secure Collusion-Resistant Functional Encryption, and More

2023 · arXiv (Cornell University)

We study certified everlasting secure functional encryption (FE) and many other cryptographic primitives in this work. Certified everlasting security roughly means the following. A receiver possessing a quantum cryptographic object can issue a certificate showing …