ZK-SNARKs, which stands for “Zero-Knowledge Succinct Non-Interactive Argument of Knowledge,” are a form of cryptographic proof that allows one party (the prover) to prove to another (the verifier) that they know a value x, without conveying any information apart from the fact they know the value x.
Here’s a more detailed explanation:
- Zero-Knowledge: This means that if the statement being proved is true, the verifier will not learn anything other than this fact. This property is what enhances privacy, because no additional information about the proof needs to be revealed.
- Succinct: This means that the proof can be verified quickly, even if it relates to a large amount of data. This is important for scalability, because it allows for the verification of complex statements without requiring a huge amount of computational resources.
- Non-Interactive: In a traditional interactive proof, the prover and verifier need to communicate back and forth for the proof to be constructed. A non-interactive proof, on the other hand, only requires a single message from the prover to the verifier, which simplifies the process considerably.
- Argument of Knowledge: This essentially means that the prover can’t convince the verifier of a false statement, unless they can break the underlying cryptographic assumptions. This provides a strong level of security, because it makes it computationally infeasible for the prover to lie.
ZK-SNARKs are used in many decentralized applications, including blockchains like Zcash, which use ZK-SNARKs to maintain the privacy of transaction data. They allow for the creation of “shielded” transactions, where the sender, receiver, and amount of a transaction can be encrypted but still be verified as valid under the network’s consensus rules.