# What is a bit commitment protocol?

## What is a bit commitment protocol?

Bit commitment is a protocol between two mistrusting parties, Alice and Bob, which is supposed to provide the following functionality: In a commit phase, Alice gives as input a value X (e.g., a bit) and Bob gets a confirmation that Alice has commited to a value (without learning the actual value of X).

## What is a commitment in cryptography?

A commitment scheme is a cryptographic primitive that allows one to commit to a chosen value (or chosen statement) while keeping it hidden to others, with the ability to reveal the committed value later.

What is a Pedersen commitment?

A Pedersen commitment is a point C on an elliptic curve that is cryptographically binding to a data message m, but completely hides the message. A Pedersen commitment hides the message in an even stronger way than encryption.

### What is quantum bit commitment?

Quantum bit commitment (QBC) is a quantum version of the classical bit commitment security primitive. As other quantum security primitives and protocols, QBC improves on cheating detection over its classical counterpart.

### What is secure commitment?

Secure commitment is a primitive enabling in- formation hiding, which is one of the most ba- sic tools in cryptography. Specifically, it is a two-party partial-information game between a committer” and a receiver”, in which a se- cure envelope is first implemented and later opened.

What is a trapdoor commitment?

We note that the trapdoor property implies that the commitment hides the message. Second, we want the commitment scheme to be homomorphic. Homomorphic means that messages and commitments belong to abelian groups and if we multiply two commitments, we get a new commitment that contains the product of the two messages.

## What is functional commitment?

non-interactive functional commitment allows committing to a message in such. a way that the committer has the flexibility of only revealing a function F(M) of the committed message during the opening phase.

## What is commit reveal?

To understand how the commit-reveal commitment scheme works, it is useful to break it down into it’s two component parts: Commit: You assert your choice to your peers. Reveal: You reveal your choice, and everyone can verify that is in fact what you committed to.