FHE Technology: The Future Path of Privacy Computing

FHE( Fully Homomorphic Encryption ) is an advanced encryption technology that allows computations to be performed directly on encrypted data, thereby processing data while protecting privacy. This technology has broad application prospects in various fields such as finance, healthcare, and cloud computing. However, the commercialization of FHE still faces challenges, primarily due to its large computational and memory overhead, as well as poor scalability.

Basic Principles of FHE

The core of FHE is to hide the original information through polynomials. The specific process includes:

1. Choose a secret polynomial
2. Generate Random Polynomial
3. Add a small "error" polynomial
4. Encrypt the original data using the above polynomial.

This method can effectively hide the original text, and only those who know the key can decrypt it. However, noise will be introduced during the computation process, making it impossible to correctly decrypt after multiple calculations. To address this issue, FHE employs the following techniques:

• Key Switching: Compressing Ciphertext Size
• Modulus switching: control noise growth
• Bootstrap: reset noise to initial level

The combination of these technologies allows FHE to support arbitrary computations of unlimited depth.

Challenges Facing FHE

The biggest challenge of FHE lies in its enormous computational overhead. Compared to ordinary computation, the computation of FHE versions may be billions of times slower. To address this issue, the U.S. DARPA launched a dedicated Dprive program, hoping to optimize FHE through the following methods:

• Increase processor word length
• Develop dedicated ASIC processors
• Build MIMD parallel architecture

However, there is still a gap between achieving the goal of 1/10 efficiency of ordinary calculations.

The Application of FHE in the Blockchain Field

In blockchain, FHE is primarily used to protect data privacy, with application areas including:

• On-chain privacy protection
• AI Training Data Privacy
• On-chain voting privacy
• On-chain privacy transaction review

FHE is also considered one of the potential solutions to the MEV problem. However, due to its enormous computational overhead, its application in the blockchain field still faces challenges.

Major FHE Projects

FHE technology is still in its early stages, with the main projects including:

• Zama: provides a TFHE-based development toolchain
• Fhenix: Building a privacy-first Layer 2 network
• Privasea: Using FHE for LLM Data Computation
• Inco Network: Building FHE Layer 1 Network
• Arcium: Integrating FHE, MPC, and ZK technologies
• Mind Network: Combining Restaking and FHE Subnetwork

Zama's technical solution has been recognized by multiple projects.

Future Prospects of FHE

Despite the many technical challenges currently facing FHE, its potential for privacy protection remains enormous. With more capital and talent being invested, FHE is expected to achieve breakthrough progress in the future. Especially after the advent of FHE-specific chips, this technology may bring profound changes in fields such as defense, finance, and healthcare.

Overall, FHE, as a cutting-edge technology, although its commercialization prospects are still unclear at present, still holds significant importance in the long run. In the future, with technological advancements and the expansion of application scenarios, FHE is expected to become an important solution in the field of privacy computing.