Crate concrete_boolean

Welcome the the concrete-boolean documentation!

Description

This library makes it possible to execute boolean gates over encrypted bits. It allows to execute a boolean circuit on an untrusted server because both circuit inputs and outputs are kept private. Data are indeed encrypted on the client side, before being sent to the server. On the server side every computation is performed on ciphertexts. The server however has to know the boolean circuit to be evaluated. At the end of the computation, the server returns the encryption of the result to the user.

Quick Example

The following piece of code shows how to generate keys and run a small Boolean circuit homomorphically.

//! use concrete_boolean::gen_keys;
use concrete_boolean::prelude::*;

// We generate a set of client/server keys, using the default parameters:
let (mut client_key, mut server_key) = gen_keys();

// We use the client secret key to encrypt two messages:
let ct_1 = client_key.encrypt(true);
let ct_2 = client_key.encrypt(false);

// We use the server public key to execute a boolean circuit:
// if ((NOT ct_2) NAND (ct_1 AND ct_2)) then (NOT ct_2) else (ct_1 AND ct_2)
let ct_3 = server_key.not(&ct_2);
let ct_4 = server_key.and(&ct_1, &ct_2);
let ct_5 = server_key.nand(&ct_3, &ct_4);
let ct_6 = server_key.mux(&ct_5, &ct_3, &ct_4);

// We use the client key to decrypt the output of the circuit:
let output_1 = client_key.decrypt(&ct_6);
assert_eq!(output_1, true);

// It is possible to compute gates with one input unencrypted
let ct_7 = server_key.and(&ct_6, true);
let output_2 = client_key.decrypt(&ct_7);
assert_eq!(output_2, true);

// It is possible to trivially encrypt on the server side
// i.e. to not encrypt but still generate a compatible Ciphertext
let ct_8 = server_key.trivial_encrypt(false);
let ct_9 = server_key.mux(&ct_7, &ct_3, &ct_8);
let output_3 = client_key.decrypt(&ct_9);
assert_eq!(output_3, true);

Modules

ciphertext

An encryption of a boolean message.

client_key

The secret key of the client.

engine

parameters

The cryptographic parameter set.

server_key

The public key for homomorphic computation.

Functions

gen_keys

Generate a couple of client and server keys with the default cryptographic parameters: DEFAULT_PARAMETERS. The client is the one generating both keys.