How does Trias protect the privacy of on-chain transactions with Zero-Knowledge Proof?
Despite its anonymity, blockchain does not naturally protect users’ privacy. On the contrary, all transaction information is on-chain, making users’ behaviors traceable. With certain analysis methods, it is possible for users’ personal information to be exposed to the world. Therefore, blockchain needs privacy protection more than reality.
Trias uses zero-knowledge proof cryptography to hide the users’ information, including the amount of the transaction, in blockchain records so that no one but the key owner can trace the entire transaction to ensure the privacy of the transaction data on the chain.
What is Zero-knowledge Proof？
Zero-knowledge Proof (ZKP) is defined as: the prover can convince the verifier that a certain assertion is correct without providing any useful information to the verifier.
Zero-Knowledge proof has three important properties:
As long as the prover has the corresponding knowledge, the prover can pass the verification of the verifier.
If the prover doesn’t have corresponding knowledge, it cannot pass the verification of the verifier, that is, the probability of the prover cheating the verifier is too tiny to be noticed.
During the interaction, the prover will only tell the verifier whether it has the corresponding knowledge, and will not reveal any additional information about the knowledge.
Application of Zero-Knowledge Proof in Trias technology
Trias uses zero-knowledge proof to secure the privacy of all transactions on the Trias Smart Contract platform by hiding the identity of the sender and receiver of the transaction from other users in the system and encrypting the balance of the transaction to keep the transaction private.
In Trias zero-knowledge proof scheme, the public parameter is (pk, vk) and the secret parameter is SK. The public parameter will be distributed to every node in the form of public text. The node generates proof using PK and the original information x, and verifies proof based on VK. Its security is based on the disclosure of (pk, vk and proof), and it is impossible to recover the original information x without knowing sk. Since sk is confidential, x’s privacy is guaranteed.
In practice, because of the openness of (pk, vk), attackers can use their own customized programs to continuously conduct tests. Each time the validator uses pk to generate a possible proof, and vk to give binary information of yes or no. In this way, it is possible to realize ciphertext-only attacks on the premise that pk and vk are known. In other words, the attack idea is not to recover sk, but to directly recover original information x based on pk, vk and proof.
Therefore, in order to enhance the capacity of resistance to the ciphertext-only attack, Trias combines the TEE trusted mechanism and makes zero-knowledge proof in the chain of trusted implementation mechanism become reality. This mechanism realizes zero-knowledge proof, and hides (pk, vitamin k), so as to avoid the ciphertext-only attack, and further enhances the security of application of zero knowledge proof on the chain. Therefore, data privacy will be better protected by making up for the above attack vulnerabilities.
In addition, Trias’ Layer -1 trusted network Leviatom, as a trusted infrastructure, provides DeFi developers with basic blockchain design modules to develop DeFi tools or applications, which would be enhanced in terms of privacy.