TFHE-rs is designed for developers and researchers who want full control over what they can do with TFHE, while not having to worry about the low-level implementation. The goal is to have a stable, simple, high-performance, and production-ready library for all the advanced features of TFHE.

Important

TFHE-rs released its first stable version v1.0.0 in February 2025, stabilizing the high-level API for the x86 CPU backend.

tfhe = { version = "*", features = ["boolean", "shortint", "integer"] }

Note

Note: You need Rust version 1.91.1 or newer to compile TFHE-rs. You can check your version with rustc --version.

Note

Note: AArch64-based machines are not supported for Windows as it's currently missing an entropy source to be able to seed the CSPRNGs used in TFHE-rs.

use tfhe::prelude::*;
use tfhe::{generate_keys, set_server_key, ConfigBuilder, FheUint32, FheUint8};
fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Basic configuration to use homomorphic integers
    let config = ConfigBuilder::default().build();
    // Key generation
    let (client_key, server_keys) = generate_keys(config);
    let clear_a = 1344u32;
    let clear_b = 5u32;
    let clear_c = 7u8;
    // Encrypting the input data using the (private) client_key
    // FheUint32: Encrypted equivalent to u32
    let mut encrypted_a = FheUint32::try_encrypt(clear_a, &client_key)?;
    let encrypted_b = FheUint32::try_encrypt(clear_b, &client_key)?;
    // FheUint8: Encrypted equivalent to u8
    let encrypted_c = FheUint8::try_encrypt(clear_c, &client_key)?;
    // On the server side:
    set_server_key(server_keys);
    // Clear equivalent computations: 1344 * 5 = 6720
    let encrypted_res_mul = &encrypted_a * &encrypted_b;
    // Clear equivalent computations: 6720 >> 5 = 210
    encrypted_a = &encrypted_res_mul >> &encrypted_b;
    // Clear equivalent computations: let casted_a = a as u8;
    let casted_a: FheUint8 = encrypted_a.cast_into();
    // Clear equivalent computations: min(210, 7) = 7
    let encrypted_res_min = &casted_a.min(&encrypted_c);
    // Operation between clear and encrypted data:
    // Clear equivalent computations: 7 & 1 = 1
    let encrypted_res = encrypted_res_min & 1_u8;
    // Decrypting on the client side:
    let clear_res: u8 = encrypted_res.decrypt(&client_key);
    assert_eq!(clear_res, 1_u8);
    Ok(())
}

Note

Note that when running code that uses TFHE-rs, it is highly recommended to run in release mode with cargo's --release flag to have the best performance possible.

Tip

On Linux, enabling transparent huge pages gives a noticeable additional speedup when using many threads. See System tuning for details.