have an account?【sign in】Zero Knowledge Proof Simple Example:A Guide to Understanding Zero-Knowledge Proofs
barriosauthorZero Knowledge Proof: A Simple Example for Understanding Zero-Knowledge Proofs
Zero-knowledge proofs (ZKP) are a powerful cryptographic tool that enables a sender to prove to a recipient that they possess certain information, without actually revealing the information itself. This is particularly useful in situations where privacy is essential, such as in blockchain applications like privacy coins or anonymous voting systems. In this article, we will provide a simple example to help you understand the concept of zero-knowledge proofs.
Zero-knowledge proofs are based on the concept of a proof system, which is a set of rules that allows one party, the prover, to provide evidence to another party, the verifier, that they hold certain knowledge without actually revealing the knowledge itself. In other words, the prover can prove to the verifier that they know a secret without revealing the secret itself.
Let's consider a simple example to better understand the concept of zero-knowledge proofs:
Assume we have a secret phrase, "The sea is calm today." We will represent this secret phrase as a string of characters, such as "S E A C A L T O D A Y."
Prover (P): I know the secret phrase: S E A C A L T O D A Y.
Verifier (V): Please provide a zero-knowledge proof that you know the secret phrase.
P: I can prove that I know the secret phrase using a zero-knowledge proof called the "Blinding Technique." Here's how it works:
P: I will blind myself by selecting a random number k between 1 and n-1, where n is the length of the secret phrase. Then, I will divide the secret phrase into two parts: the first part is S E A C A L T O D A Y and the second part is k.
V: Please reveal the blinded secret phrase and the blind factor k.
P: The blinded secret phrase is S E A C A L T O D A Y and the blind factor k is 3, because I selected 3 as the blind factor.
V: I believe that you know the secret phrase because the blinded secret phrase matches the one you provided and the blind factor is correct. However, I still need to verify that you know the secret phrase without actually revealing the secret phrase itself.
P: I can prove that I know the secret phrase using another zero-knowledge proof called the "Signature Proof." Here's how it works:
P: I have a private key (privkey) and a signature (sig) on the blinded secret phrase: S E A C A L T O D A Y k 3.
V: Please provide the public key.
P: The public key is the same as the privkey.
V: I believe that you know the secret phrase because the signature is valid using the public key and the blinded secret phrase matches the one you provided and the blind factor is correct.
In this simple example, we have seen how zero-knowledge proofs can be used to prove that a prover knows a secret phrase without actually revealing the secret phrase itself. This is particularly useful in situations where privacy is essential, such as in blockchain applications like privacy coins or anonymous voting systems. As technology continues to advance, zero-knowledge proofs will likely play an increasingly important role in ensuring data privacy and security.