Homomorphic encryption is a revolutionary breakthrough in the field of cryptography, allowing computations to be performed on encrypted data without any need to decrypt it beforehand. This technology, though theorised since the 1970s, has seen its practical development accelerate over the past decade thanks to increased computing power and mathematical advances. Its promises are many, particularly when it comes to data privacy and security in sectors as varied as finance, healthcare and artificial intelligence.
How Does Homomorphic Encryption Work?
The fundamental principle of homomorphic encryption rests on the possibility of carrying out certain mathematical operations on encrypted data. For example, a company can send sensitive data to a cloud computing server for processing. Thanks to this technology, the server can perform operations on that data without ever seeing it in the clear, thereby guaranteeing complete confidentiality.
There are principally two types of homomorphic encryption:
- Partial homomorphic encryption: this allows either additions or multiplications, but not both simultaneously, to be performed on encrypted data.
- Fully homomorphic encryption: far more complex, this allows all arithmetic operations to be carried out on encrypted data, thereby offering total flexibility for a range of applications.
The Advantages of Homomorphic Encryption
Homomorphic encryption offers several key advantages:
- Data confidentiality: information remains encrypted throughout the processing, which significantly reduces the risk of a breach of sensitive data.
- Security in the cloud: by ensuring that cloud service providers never have access to data in the clear, this technology allows for a safer adoption of cloud services, even for the most sensitive information.
- Multiple applications: the fields of finance, healthcare and government services are among the first to benefit from this technology. Moreover, applications are emerging in the fields of artificial intelligence, blockchain and even electronic voting systems.
Examples of Use
- Secure machine learning: by integrating homomorphic encryption into artificial intelligence workflows, it becomes possible to train AI models on encrypted data without compromising user privacy. For instance, Zama has developed machine learning (ML) frameworks with libraries such as Concrete, facilitating training and inference on encrypted data.
- Blockchain and smart contracts: Zama also offers a solution called fhEVM that allows confidential smart contracts to be written on EVM-compatible chains (Ethereum Virtual Machine). This opens the way to applications such as anonymous auctions or the secure management of identities.
- Financial systems: companies can use homomorphic encryption to process financial transactions while ensuring that even operators or intermediaries cannot access users' data.
Why This Technology Is Promising
Homomorphic encryption has the potential to transform the way we handle sensitive data. By allowing computations on encrypted data, this technology renders obsolete the trade-off between security and usability. What is more, it can be integrated into critical fields such as healthcare or finance, where data confidentiality is paramount.
Challenges do, however, remain. The computing power required to carry out these operations is still high, potentially slowing down certain large-scale applications. But with the continuous improvement of hardware and software technologies, these limitations should diminish over time.
Conclusion
Homomorphic encryption is emerging as a promising solution, on a par with recursive SNARKs, for ensuring the protection and decentralisation of data. By combining this technology with artificial intelligence models and smart oracles, it becomes possible to achieve an unprecedented level of security. Moreover, this approach could facilitate a smooth and seamless transition from Web2 to Web3. It represents a path towards the future for building a free, sovereign and decentralised Internet, where cutting-edge technologies such as artificial intelligence and blockchain can flourish and guarantee optimal data protection while fostering decentralised governance.