Category: QuantumProtocolZoo

Functionality Description Entanglement verification is a cryptographic functionality that allows one or more parties to verify the presence and quality of quantum entanglement between distant or untrusted devices or parties[1,2]. This functionality is crucial in quantum networks and cryptographic protocols where trust in devices or remote quantum systems cannot be assumed. This is a fundamentally…

Functionality Description Digital Signatures (QDS) allow the exchange of classical messages from sender to multiple recipients, with a guarantee that the signature has come from a genuine sender. Additionally, it comes with the properties of transferability, non-repudiation and unforgeability. In contrast, classical digital signatures rely on authentication (taken as an assumption for some QDS protocols)…

Functionality Description Copy Protection is a functionality first defined by Aaronson [1] that enables a Vendor to send a program (a circuit) to a Client so that the Client cannot duplicate it. Classically, this functionality has been proven impossible. However, it is possible to copy protect some families of programs using quantum computation. Protocols The…

Functionality Description Bit commitment is a fundamental cryptographic primitive between two parties that allows one party (the committer) to choose a bit (or more generally, a value), commit to it while keeping it hidden, and later reveal it to another party (the receiver) in a way that guarantees consistency. It acts like a sealed envelope:…

Functionality Description Coin flipping is a cryptographic primitive which allows two mistrustful parties, Alice and Bob, to remotely generate a random bit, such that none of the two parties can bias the outcome beyond a specified probability [1]. One can think of this functionality as agreeing on a coin flip over the phone. More explicitly,…

Functionality Description Anonymous transmission is a multipartite task which enables two nodes to communicate a message in a network in an anonymous way. More specifically, one of the nodes of the network, a sender, communicates a quantum state to a receiver in a way that their identities remain completely hidden throughout the protocol. In particular,…

Functionality Description Quantum authentication allows the exchange of quantum messages between two parties over a insecure quantum channel with the guarantee that the received quantum information is the same as the initially sent quantum message. Imagine a person sends some quantum information to another person over an insecure channel, where a dishonest party has access…

Functionality Description Byzantine agreement[1,2] is a classical problem concerned with reaching agreement on a single bit of data in a network of $n$ players, out of which $t$ players may be faulty. Each player starts with an input bit $b_{i}$ and the objective is that all non-faulty players output the same bit $d$ (agreement), under…