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

In today's era, where data security and privacy protection face tremendous challenges, encryption technology plays a crucial role. This article will provide a detailed comparison of three advanced encryption technologies: Fully Homomorphic Encryption (FHE), Zero-Knowledge Proof (ZK), and Multi-Party Computation (MPC).

Zero Knowledge Proof ( ZK ): Prove without revealing

Zero-knowledge proof technology aims to address the problem of verifying the authenticity of information without disclosing any specific content. Through ZK, one party can prove to another party that they know a certain secret without revealing any information about the secret itself.

For example, Alice can prove her good credit to the car rental employee Bob without showing specific account statements. In blockchain applications, ZK technology can be used to achieve anonymous transactions, such as the transfer process of a certain anonymous currency. Miners can verify the legitimacy of transactions and add them to the blockchain without knowing the identity of the sender.

Multi-Party Secure Computation ( MPC ): Joint computation without leakage

MPC technology is mainly used to allow multiple participants to securely perform joint computations without disclosing sensitive information. It enables several participants to collaboratively complete computational tasks without any party revealing its input data.

A typical application scenario is to calculate the average salary of multiple people without disclosing individual salary data. In the encryption currency field, MPC technology is used to develop more secure wallet solutions. Some trading platforms have launched MPC wallets that split private keys into multiple parts, stored separately on the user's phone, in the cloud, and on the exchange, enhancing asset security and recovery convenience.

Fully Homomorphic Encryption ( FHE ): Encryption Outsourcing Computation

Fully homomorphic encryption technology solves the problem of how to encrypt sensitive data so that it can be assisted in computation by untrusted third parties, while ensuring that the results can be correctly decrypted. FHE allows computation to be performed while the data remains in an encrypted state, which is particularly important for processing sensitive information in cloud computing environments.

In the field of blockchain, FHE technology can be used to address issues such as nodes slacking off and voting trends in small PoS networks. Through FHE, PoS nodes can complete block validation without knowing each other's answers, or allow voters to participate in voting without being aware of others' intentions, thereby enhancing the level of decentralization in the network and the authenticity of the votes.

Technical Comparison

Although these three technologies are dedicated to protecting data privacy and security, there are significant differences in their application scenarios and technical complexity.

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

In terms of technical complexity, ZK requires a deep understanding of mathematics and programming skills to design effective protocols. MPC needs to address synchronization and communication efficiency issues during implementation, especially in cases with multiple parties involved. Although FHE is theoretically very attractive, it still faces significant challenges in computational efficiency in practical applications.

These three encryption technologies provide us with powerful tools to address the increasingly severe challenges of data security and privacy protection. As technology continues to evolve and improve, they will play an increasingly important role in the future digital world.