Secret Arithmetic Server Using TFHE-rs

About

Fully Homomorphic Encryption (FHE) is a groundbreaking technology in the field of cryptography that enables computation on encrypted data without ever needing to decrypt it. This means that sensitive information can be processed in encrypted form, maintaining data privacy and security throughout the computation process. The advent of FHE opens up new possibilities for secure data analysis, cloud computing, and privacy-preserving technologies.

Torus FHE is a specific implementation of Fully Homomorphic Encryption that leverages the mathematical structure of a torus for efficient and secure computations. This approach aims to address some of the key challenges in FHE, such as computational complexity and performance scalability, making it more practical for real-world applications

This is a reference implementation that demonstrates the key generation and FHE computations on encrypted data.

Usage

In this scenario we will have Alice and Bob

Name	Role
Alice	Client
Bob	Server

Alice wants to add two secret numbers a and b

Building

Install Rust development environment

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Generating client keys

As Alice generate a new client key with a seed

target/release/create_client <seed>

Where seed is an unsigned 128-bit integer. (0 .. 340282366920938463463374607431768211455)

Example

target/release/create_client 113427455640312821154458222707257705001

This generates a file client.json in the $PWD

Generating Request

Operations

Operation	Opcode	Arithmetic Operator
1	Add	a + b
2	Sub	a - b
3	Mul	a * b
4	Div	a / b
5	BitAnd	a & b
6	BitAndAssign	a &= b
7	BitOr	a | b
8	BitXor	a ^ b
9	BitXorAssign	a ^= b
10	DivAssign	a /= b
11	RotateLeft	ROL(a)
TODO

Starting the secret arithmetic server

As Bob

Open a new terminal window or tab

target/release/arithmetic_server 

Creating a request

Addition

As Alice create a new addition opcode 1 request using her private key client.json

This will:

1. Encrypt the values 32901 and 99021
2. Generate a new ServerKey
3. Creates the request.json payload which contains the encrypted values, the server key, and the encrypted values.

create_request client.json 1 32901 99021

Sending the request

Alice does an HTTP POST with the request.json to Bob's server running on https://127.0.0.1:3000

curl -X POST -H "Content-Type: application/json" -d @request.json http://localhost:3000/job -o answer.json

This generates an output answer.json

Decrypting the answer

Alice can get the answer by decrypting the answer.json with her private key client.json

 target/release/reveal_answer answer.json client.json

If all goes well then this should output:

answer = 131922