FHE, ZK, MPC: A Comparison of Three Advanced Encryption Technologies

In today's digital age, data security and privacy protection have become increasingly important. Fully Homomorphic Encryption (FHE), Zero-Knowledge Proof (ZK), and Multi-Party Computation (MPC) are three advanced encryption technologies that have garnered significant attention, each playing a vital role in different scenarios. This article will provide a detailed comparison of these three technologies, helping readers better understand their characteristics and applications.

Zero-Knowledge Proof (ZK): Proving without Revealing

Zero-knowledge proof technology addresses the problem of verifying the authenticity of information without disclosing specific details. It allows one party (the prover) to demonstrate to another party (the verifier) that they know a certain secret without revealing any specific information about that secret.

For example, Alice can prove her good credit to the car rental employee Bob without having to show specific bank statements. In the blockchain field, the anonymous currency Zcash has applied this technology. Users can prove their right to conduct transactions while remaining anonymous, thus avoiding the double-spending problem.

Multi-Party Computation (MPC): Joint Computation without Disclosure

Multi-party secure computation technology allows multiple participants to collaboratively complete computation tasks without revealing their respective input data. For example, several people can calculate their average salary without disclosing their specific salaries.

In the cryptocurrency space, MPC technology is used to develop more secure wallets. Some trading platforms have launched MPC wallets that split the private key into multiple parts, which are stored separately on the user's mobile phone, in the cloud, and on the platform. This method not only enhances security but also increases the possibility of recovery.

Fully Homomorphic Encryption (FHE): Encrypted computation does not leak

Fully homomorphic encryption technology allows computations to be performed on encrypted data, while the results can still be decrypted by the original data owner. This enables users to hand over encrypted sensitive data to untrusted third parties for processing without worrying about data leakage.

In the field of blockchain, FHE technology can be used to address the issues of node laziness and vote following in small-scale PoS networks. For example, certain projects utilize FHE technology to allow PoS nodes to complete block validation without knowing the answers of other nodes, preventing nodes from copying each other. Similarly, in voting systems, FHE can prevent voters from influencing each other, ensuring that the voting results are more authentic.

Technical Comparison

Although these three technologies are all aimed at protecting data privacy and security, there are differences in their application scenarios and technical complexity:

• ZK is mainly used for proof and is suitable for scenarios that require verification of permissions or identity.
• MPC focuses on multi-party computation, suitable for situations that require data collaboration while protecting the privacy of all parties.
• FHE focuses on encryption data processing, particularly suitable for fields such as cloud computing and AI services.

In terms of technical complexity, ZK requires deep mathematical and programming skills; MPC faces synchronization and communication efficiency issues when multiple parties are involved; FHE still faces significant challenges in computational efficiency.

As the digitalization process deepens, these encryption technologies will play an increasingly important role in protecting our data security and personal privacy. Understanding their differences and application scenarios is crucial for better protecting ourselves in the digital age.