This document details the bitwise operations supported by TFHE-rs.
Homomorphic integer types support the following bitwise operations:
name
symbol
type
!
Unary
&
Binary
|
Binary
^
Binary
>>
Binary
<<
Binary
rotate_right
Binary
rotate_left
Binary
The following example shows how to perform bitwise operations:
use tfhe::prelude::*;
use tfhe::{generate_keys, set_server_key, ConfigBuilder, FheUint8};
fn main() -> Result<(), Box<dyn std::error::Error>> {
let config = ConfigBuilder::default().build();
let (keys, server_keys) = generate_keys(config);
set_server_key(server_keys);
let clear_a = 164;
let clear_b = 212;
let mut a = FheUint8::try_encrypt(clear_a, &keys)?;
let mut b = FheUint8::try_encrypt(clear_b, &keys)?;
a ^= &b;
b ^= &a;
a ^= &b;
let dec_a: u8 = a.decrypt(&keys);
let dec_b: u8 = b.decrypt(&keys);
// We homomorphically swapped values using bitwise operations
assert_eq!(dec_a, clear_b);
assert_eq!(dec_b, clear_a);
Ok(())
}