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

In the field of encryption, Fully Homomorphic Encryption ( FHE ), Zero-Knowledge Proof ( ZK ), and Multi-Party Computation ( MPC ) are three highly regarded technologies. Although they all aim to protect data privacy and security, there are significant differences in their specific application scenarios and technical complexities. This article will delve into the characteristics of these three technologies and their applications in areas such as blockchain.

Zero-Knowledge Proof ( ZK ): Prove without revealing

The core issue of discussing zero-knowledge proof technology is: how to verify the authenticity of information without revealing specific content. ZK allows one party ( prover ) to prove to another party ( verifier ) the truth of a statement, without disclosing any additional information beyond the truth of that statement.

In practical applications, ZK can be used for scenarios such as authentication and anonymous transactions. For example, in certain anonymous cryptocurrencies, users can prove through ZK that they have sufficient balance to make a transaction without exposing their identity or specific balance information.

Multi-Party Secure Computation ( MPC ): Secure Collaborative Computing

Multi-party secure computation technology is mainly used to solve how to allow multiple participants to jointly complete computational tasks without leaking sensitive information. MPC enables multiple parties to collaborate on complex calculations, but each participant can only see their own inputs and the final results, without being able to know the input data of other participants.

In the field of cryptocurrency, MPC technology has been applied to develop more secure digital wallets. For example, MPC wallets launched by certain trading platforms divide private keys into multiple parts, which are separately stored by user devices, the cloud, and the platform, thereby enhancing asset security and recovery convenience.

Fully Homomorphic Encryption ( FHE ): Data processing in an encrypted state

Fully Homomorphic Encryption (FHE) technology addresses how to perform computational operations while keeping data in an encrypted state. FHE allows for arbitrary complex computations on encrypted data without the need for decryption. This means that data owners can hand over sensitive encrypted data to a third party for processing without the third party being able to know the contents of the original data.

In the field of blockchain, FHE technology can be used to improve the PoS consensus mechanism and voting systems. For example, certain projects are exploring the use of FHE technology to enable PoS nodes to complete block validation without knowing the answers of other nodes, thereby preventing plagiarism among nodes and enhancing the degree of decentralization.

Comparison of Technical Features

1. Application Focus:

   • ZK: Emphasize "how to prove"
   • MPC: Focused on "how to compute"
   • FHE: Focuses on "how to encryption"

2. Technical Complexity:

   • ZK: Designing effective and easily implementable protocols is relatively complex.
   • MPC: Facing challenges in synchronization and communication efficiency
   • FHE: The computational efficiency is the main bottleneck.

3. Practical Application:

   • ZK: Widely used in identity verification and anonymous transactions
   • MPC: Applied in digital wallets and cross-institutional data analysis.
   • FHE: Shows potential in cloud computing and AI fields

These three encryption technologies each have their advantages and together form an important pillar of modern cryptography. With the continuous development and improvement of technology, they will play an increasingly important role in protecting data privacy and enhancing information security, providing a solid foundation for building a safer and more trustworthy digital world.