Zero-Knowledge Proof – ZKP (zero-knowledge proof) is changing the way we protect data on blockchain, providing greater security and privacy.
Zero-Knowledge Proof (ZKP) is an important concept in modern cryptography. ZKPs allow one party (the prover) to prove a claim to be true to another party (the verifier) without revealing any information other than the truth of the claim. This principle brings a major breakthrough in protecting personal information and transactions on the blockchain.
The ZKP principles include three main elements: completeness, correctness and non-disclosure. Completeness ensures that if the statement is true, the verifier will always accept the proof. Correctness ensures that if the statement is false, the verifier will not be convinced by any evidence. Finally, non-disclosure ensures that the verifier does not learn anything other than the correctness of the statement.
ZKP types
There are two main types of ZKP: interactive proof and non-interactive proof. Interactive proofs require multiple exchanges between the prover and verifier, while non-interactive proofs do not require interaction after the proof has been generated.
Interactive proofs require a series of back-and-forth exchanges between the prover and the verifier. During this process, the verifier issues challenges for the prover to answer. If the prover can meet all the challenges correctly, the verifier will believe that the statement is true without revealing further information.
For example, imagine you need to prove that you know the password to a safe without revealing the password. You will ask the verifier to give you random challenges related to opening the safe, and you will perform the proof steps without ever revealing the password. However, these interactive proofs are rarely used in blockchain systems because they are inefficient and require two parties to be online at the same time.
zk-SNARKs (Succinct Non-Interactive Arguments of Knowledge) are a type of non-interactive ZKP. zk-SNARKs allows you to prove that you own certain information without revealing details about that information. On the Ethereum blockchain, zk-SNARKs are useful for smart contracts that protect privacy. zk-SNARKs are also used by ZCash to verify anonymous transactions, ensuring that no information about the sender, recipient or amount is revealed.
zk-STARKs (Scalable Transparent Arguments of Knowledge) works similarly to zk-SNARKs but is designed to scale large computations. Due to its transparency and scalability benefits, zk-STARKs is compatible with many different blockchain applications.
Bulletproofs prove that a value is within a specific range without revealing that value. Through the use of advanced mathematical concepts, bulletproofs can make proofs smaller, thereby reducing transaction size and verification time. Monero uses bulletproofs to improve the privacy and performance of cryptocurrency transactions.
Application of ZKP in blockchain
ZKP's applications in blockchain are diverse, from securing transactions to ensuring privacy in voting and transparency in the supply chain. Layer 2 solutions on Ethereum are also using ZKP to enhance scalability and security.
Zk-rollups are layer 2 scaling solutions that bundle off-chain transaction data into a cryptographic proof, then use ZKP to post the transaction validity to the Ethereum mainnet as calldata. Since transactions are posted to the mainnet in aggregated form, they typically take up less space, thus reducing the computational burden on Ethereum. Popular zk-rollups include ZkSync and Loopring.
Zk-Plasma is a variant of the Plasma network that uses ZKP to create a privacy-preserving sidechain on Ethereum. Instead of verifying all data on the mainnet, users can verify transactions on the sidechain and then use ZKP to post their validity to Ethereum.
Decentralized Exchanges (DEXes): ZKP can support trading of multiple assets without revealing users' trading history, strategies or account balances. This helps protect the privacy and safety of participants trading on decentralized exchanges.
Transaction security: ZKP allows transactions on the blockchain to be conducted privately without revealing details. This is especially important for cryptocurrency transactions, where privacy is key.
Secure voting: ZKP can be used to ensure that votes are counted accurately without revealing individual voters' choices. This results in a more transparent and secure voting system.
Supply Chain Transparency: In the supply chain, ZKP can be used to demonstrate product origin and integrity without revealing sensitive information about suppliers or manufacturing processes.
Challenges and future of ZKP
Although ZKPs offer many benefits, they also face some challenges. High computational demands are one of the main barriers, as ZKP algorithms require large processing power. Setup complexity and ensuring compatibility between different systems are also challenges that need to be addressed.
However, ZKP's potential to enhance blockchain security and privacy is huge. Research and development are continuing to improve the performance and reduce costs of ZKP. In the future, we can see ZKP being applied more widely in financial systems, smart contracts, and many other fields.
Zero-Knowledge Proof is a powerful tool for protecting data and transactions on the blockchain. Despite facing many challenges, ZKP is opening up new opportunities for enhancing security and privacy in the digital age.
