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Random Oracles in a Quantum World
TLDR
It is shown that certain post-quantum proposals, including ones based on lattices, can be proven secure using history-free reductions and are therefore postquantum secure.
The Operational Meaning of Min- and Max-Entropy
TLDR
The results establish a direct connection between min- and max-entropies, known to characterize information-processing tasks such as randomness extraction and state merging, and basic operational problems.
Leftover Hashing Against Quantum Side Information
TLDR
A strictly more general version of the Leftover Hash Lemma that is valid even if side information is represented by the state of a quantum system is shown and applies to almost two-universal families of hash functions.
Quantum Homomorphic Encryption for Polynomial-Sized Circuits
TLDR
A new scheme for quantum homomorphic encryption which is compact and allows for efficient evaluation of arbitrary polynomial-sized quantum circuits, and a three-round scheme for blind delegated quantum computation which puts only very limited demands on the quantum abilities of the client.
Position-Based Quantum Cryptography: Impossibility and Constructions
TLDR
It is proved that with the help of sufficient pre-shared entanglement, any non-local quantum computation, i.e., any computation that involves quantum inputs from two parties at different locations, can be performed instantaneously and without any communication, up to local corrections that need to be applied to the outputs.
A Concrete Treatment of Fiat-Shamir Signatures in the Quantum Random-Oracle Model
TLDR
The goal of this current paper is to create a generic framework for constructing tight reductions in the QROM from underlying hard problems to Fiat-Shamir signatures.
Leftover Hashing against quantum side information
TLDR
A (strictly) more general version of the Leftover Hash Lemma that is valid even if side information is represented by the state of a quantum system is proved and applies to arbitrary δ-almost two-universal families of hash functions.
Semantic Security and Indistinguishability in the Quantum World
TLDR
This work shows that stronger notions of indistinguishability are achievable, and provides a secure construction based on quantum-resistant pseudorandom permutations that can be used as a generic transformation for turning a large class of encryption schemes into quantum indistinguishable and hence quantum semantically secure ones.
Security and Composability of Randomness Expansion from Bell Inequalities
TLDR
A meaningful lower bound on the min-entropy of the data produced by an untrusted device based on the observed nonlocal behavior of the device is obtained and confirms the essence of the (improperly formulated) claims of Pironio et al. and puts them on solid ground.
Quantum cryptography beyond quantum key distribution
TLDR
This review article, aimed primarily at cryptographers unfamiliar with the quantum world, survey the area of theoretical quantum cryptography, with an emphasis on the constructions and limitations beyond the realm of QKD.
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