-
Notifications
You must be signed in to change notification settings - Fork 36
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Starting better documentation (#135)
- Loading branch information
Showing
3 changed files
with
91 additions
and
54 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,81 @@ | ||
| # fhe [](https://crates.io/crates/fhe) | ||
|
|
||
| **A pure-Rust implementation of fully homomorphic encryption schemes based on Ring-LWE.** | ||
|
|
||
| This library implements [Fully Homomorphic Encryption](https://en.wikipedia.org/wiki/Homomorphic_encryption#Fully_homomorphic_encryption) schemes, i.e., encryption schemes which perform implicit additions and multiplications on plaintext values while exclusively manipulating encrypted data. | ||
|
|
||
| This library provides implementations of: | ||
|
|
||
| * BFV, the Brakerski-Fan-Vercauteren (BFV) homomorphic encryption scheme. | ||
| More precisely, this library implements a leveled variant of the [HPS](https://eprint.iacr.org/2018/117) (Halevi--Polyakov--Shoup) RNS-variant of the scheme. | ||
|
|
||
| ## Example | ||
|
|
||
| Below is a simple example using BFV of an homomorphic multiplication. | ||
| One ciphertext encrypts the value `20` using the secret key, and one ciphertext encrypts the value `-7` using the public key. The ciphertexts are then multiplied, and after decryption, the program checks that the decrypted value has `20 * (-7) = -140` in the first coefficient. | ||
|
|
||
| ```rust | ||
| use fhe::bfv::{BfvParametersBuilder, Ciphertext, Encoding, Plaintext, PublicKey, SecretKey}; | ||
| use fhe_traits::*; | ||
| use rand::{rngs::OsRng, thread_rng}; | ||
| use std::sync::Arc; | ||
|
|
||
| fn main() { | ||
| let parameters = Arc::new( | ||
| BfvParametersBuilder::new() | ||
| .set_degree(2048) | ||
| .set_moduli(&[0x3fffffff000001]) | ||
| .set_plaintext_modulus(1 << 10) | ||
| .build() | ||
| .unwrap(), | ||
| ); | ||
| let mut rng = thread_rng(); | ||
|
|
||
| let secret_key = SecretKey::random(¶meters, &mut OsRng); | ||
| let public_key = PublicKey::new(&secret_key, &mut rng); | ||
|
|
||
| let plaintext_1 = Plaintext::try_encode(&[20_u64], Encoding::poly(), ¶meters).unwrap(); | ||
| let plaintext_2 = Plaintext::try_encode(&[-7_i64], Encoding::poly(), ¶meters).unwrap(); | ||
|
|
||
| let ciphertext_1: Ciphertext = secret_key.try_encrypt(&plaintext_1, &mut rng).unwrap(); | ||
| let ciphertext_2: Ciphertext = public_key.try_encrypt(&plaintext_2, &mut rng).unwrap(); | ||
|
|
||
| let result = &ciphertext_1 * &ciphertext_2; | ||
|
|
||
| let decrypted_plaintext = secret_key.try_decrypt(&result).unwrap(); | ||
| let decrypted_vector = Vec::<i64>::try_decode(&decrypted_plaintext, Encoding::poly()).unwrap(); | ||
|
|
||
| assert_eq!(decrypted_vector[0], -140); | ||
| } | ||
| ``` | ||
|
|
||
| Note that operations actually happen modulo the `plaintext_modulus`, here set to `1024 (= 1 << 10)`; for example, we would have had that the homomorphic multiplication of `805` and `-7` is `509 = (805 * (-7)) mod 1024`. Additionally, the `poly()` encoding means that the vector being encoded corresponds to the coefficients of a polynomial in `(ZZ / (1024))[x] / (x^2048+1)` (and homomorphic multiplication happens in that ring); here since only one coefficient is provided, the value is placed in the constant coefficient. The library also contains a `simd()` encoding, which enables component-wise operation on the values of the vector, provided the technical limitation that the plaintext modulus is congruent to `1` modulo twice the polynomial degree. | ||
|
|
||
| ## Examples | ||
|
|
||
| More examples exercizing multiple functions from the API are provided in the repository [`examples/`](./examples/). For example, this library implements [SealPIR](https://eprint.iacr.org/2017/1142) and [MulPIR](https://eprint.iacr.org/2019/1483), which can be run as follows: | ||
|
|
||
| ```bash | ||
| cargo run --release --example sealpir | ||
| ``` | ||
|
|
||
| and | ||
|
|
||
| ```bash | ||
| cargo run --release --example mulpir | ||
| ``` | ||
|
|
||
| ## Performance | ||
|
|
||
| Micro benchmarks can be obtained by running `cargo bench`. This crate uses [criterion.rs](https://criterion.rs) for benchmarks. | ||
|
|
||
| ## Unit tests | ||
|
|
||
| Run tests with `cargo test`. | ||
|
|
||
| ## ⚠️ Security / Stability | ||
|
|
||
| The implementations in this crate have never been independently audited for security. | ||
| Additionally, no promise on the API and ABI stability will be made until version `1.0.0` of the crate. | ||
|
|
||
| Use at your own risk. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters