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use crate::integer::ciphertext::CrtCiphertext;
use crate::integer::ServerKey;
#[cfg(test)]
mod tests;
#[cfg(test)]
pub(crate) fn make_basis(message_modulus: u64) -> Vec<u64> {
match message_modulus {
2 => vec![2],
3 => vec![2],
n if n < 8 => vec![2, 3],
n if n < 16 => vec![2, 5, 7],
_ => vec![3, 7, 13],
}
}
mod add_crt;
mod mul_crt;
mod neg_crt;
mod scalar_add_crt;
mod scalar_mul_crt;
mod scalar_sub_crt;
mod sub_crt;
impl ServerKey {
/// Extract all the messages.
///
/// # Example
///
///```rust
/// use tfhe::integer::gen_keys_crt;
/// use tfhe::shortint::parameters::PARAM_MESSAGE_3_CARRY_3_KS_PBS_GAUSSIAN_2M128;
///
/// // Generate the client key and the server key:
/// let basis = vec![2, 3, 5];
/// let modulus: u64 = basis.iter().product();
/// let (cks, sks) = gen_keys_crt(PARAM_MESSAGE_3_CARRY_3_KS_PBS_GAUSSIAN_2M128, basis);
///
/// let clear_1 = 14;
/// let clear_2 = 14;
/// // Encrypt two messages
/// let mut ctxt_1 = cks.encrypt(clear_1);
/// let ctxt_2 = cks.encrypt(clear_2);
///
/// // Compute homomorphically a multiplication
/// sks.unchecked_crt_add_assign(&mut ctxt_1, &ctxt_2);
///
/// sks.full_extract_message_assign(&mut ctxt_1);
///
/// // Decrypt
/// let res = cks.decrypt(&ctxt_1);
/// assert_eq!((clear_1 + clear_2) % modulus, res);
/// ```
pub fn full_extract_message_assign(&self, ctxt: &mut CrtCiphertext) {
for ct_i in ctxt.blocks.iter_mut() {
self.key.message_extract_assign(ct_i);
}
}
/// Computes a PBS for CRT-compliant functions.
///
/// # Warning
/// This allows to compute programmable bootstrapping over integers under the condition that
/// the function is said to be CRT-compliant. This means that the function should be correct
/// when evaluated on each modular block independently (e.g. arithmetic functions).
///
/// # Example
///
/// ```rust
/// use tfhe::integer::gen_keys_crt;
/// use tfhe::shortint::parameters::PARAM_MESSAGE_3_CARRY_3_KS_PBS_GAUSSIAN_2M128;
///
/// // Generate the client key and the server key:
/// let basis = vec![2, 3, 5];
/// let modulus: u64 = basis.iter().product();
/// let (cks, sks) = gen_keys_crt(PARAM_MESSAGE_3_CARRY_3_KS_PBS_GAUSSIAN_2M128, basis);
///
/// let clear_1 = 28;
///
/// let mut ctxt_1 = cks.encrypt(clear_1);
///
/// // Compute homomorphically the crt-compliant PBS
/// sks.pbs_crt_compliant_function_assign(&mut ctxt_1, |x| x * x * x);
///
/// // Decrypt
/// let res = cks.decrypt(&ctxt_1);
/// assert_eq!((clear_1 * clear_1 * clear_1) % modulus, res);
/// ```
pub fn pbs_crt_compliant_function_assign<F>(&self, ct1: &mut CrtCiphertext, f: F)
where
F: Fn(u64) -> u64,
{
let basis = &ct1.moduli;
let lookup_tables = basis
.iter()
.copied()
.map(|b| self.key.generate_lookup_table(|x| f(x) % b));
for (block, acc) in ct1.blocks.iter_mut().zip(lookup_tables) {
self.key.apply_lookup_table_assign(block, &acc);
}
}
pub fn pbs_crt_compliant_function<F>(&self, ct1: &CrtCiphertext, f: F) -> CrtCiphertext
where
F: Fn(u64) -> u64,
{
let mut ct_res = ct1.clone();
self.pbs_crt_compliant_function_assign(&mut ct_res, f);
ct_res
}
}