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use crate::{CrtCiphertext, ServerKey};
impl ServerKey {
/// Computes homomorphically a subtraction between two ciphertexts encrypting integer values.
///
/// This function computes the subtraction without checking if it exceeds the capacity of the
/// ciphertext.
///
/// The result is returned as a new ciphertext.
/// # Example
///
///```rust
/// use concrete_integer::gen_keys;
/// use concrete_shortint::parameters::PARAM_MESSAGE_2_CARRY_2;
///
/// // Generate the client key and the server key:
/// let (cks, sks) = gen_keys(&PARAM_MESSAGE_2_CARRY_2);
///
/// let clear_1 = 14;
/// let clear_2 = 5;
/// let basis = vec![2, 3, 5];
/// // Encrypt two messages
/// let mut ctxt_1 = cks.encrypt_crt(clear_1, basis.clone());
/// let mut ctxt_2 = cks.encrypt_crt(clear_2, basis.clone());
///
/// let ctxt = sks.unchecked_crt_sub_parallelized(&mut ctxt_1, &mut ctxt_2);
///
/// // Decrypt
/// let res = cks.decrypt_crt(&ctxt);
/// assert_eq!((clear_1 - clear_2) % 30, res);
/// ```
pub fn unchecked_crt_sub_parallelized(
&self,
ctxt_left: &CrtCiphertext,
ctxt_right: &CrtCiphertext,
) -> CrtCiphertext {
let mut result = ctxt_left.clone();
self.unchecked_crt_sub_assign_parallelized(&mut result, ctxt_right);
result
}
/// Computes homomorphically a subtraction between two ciphertexts encrypting integer values.
///
/// This function computes the subtraction without checking if it exceeds the capacity of the
/// ciphertext.
///
/// The result is assigned to the `ct_left` ciphertext.
/// # Example
///
///```rust
/// use concrete_integer::gen_keys;
/// use concrete_shortint::parameters::PARAM_MESSAGE_2_CARRY_2;
///
/// // Generate the client key and the server key:
/// let (cks, sks) = gen_keys(&PARAM_MESSAGE_2_CARRY_2);
///
/// let clear_1 = 14;
/// let clear_2 = 5;
/// let basis = vec![2, 3, 5];
/// // Encrypt two messages
/// let mut ctxt_1 = cks.encrypt_crt(clear_1, basis.clone());
/// let mut ctxt_2 = cks.encrypt_crt(clear_2, basis.clone());
///
/// let ctxt = sks.unchecked_crt_sub_parallelized(&mut ctxt_1, &mut ctxt_2);
///
/// // Decrypt
/// let res = cks.decrypt_crt(&ctxt);
/// assert_eq!((clear_1 - clear_2) % 30, res);
/// ```
pub fn unchecked_crt_sub_assign_parallelized(
&self,
ctxt_left: &mut CrtCiphertext,
ctxt_right: &CrtCiphertext,
) {
let neg = self.unchecked_crt_neg_parallelized(ctxt_right);
self.unchecked_crt_add_assign_parallelized(ctxt_left, &neg);
}
/// Computes homomorphically the subtraction between ct_left and ct_right.
///
/// # Example
///
///```rust
/// use concrete_integer::gen_keys;
/// use concrete_shortint::parameters::PARAM_MESSAGE_2_CARRY_2;
///
/// // Generate the client key and the server key:
/// let (cks, sks) = gen_keys(&PARAM_MESSAGE_2_CARRY_2);
///
/// let clear_1 = 14;
/// let clear_2 = 5;
/// let basis = vec![2, 3, 5];
/// // Encrypt two messages
/// let mut ctxt_1 = cks.encrypt_crt(clear_1, basis.clone());
/// let mut ctxt_2 = cks.encrypt_crt(clear_2, basis.clone());
///
/// let ctxt = sks.smart_crt_sub_parallelized(&mut ctxt_1, &mut ctxt_2);
///
/// // Decrypt
/// let res = cks.decrypt_crt(&ctxt);
/// assert_eq!((clear_1 - clear_2) % 30, res);
/// ```
pub fn smart_crt_sub_parallelized(
&self,
ctxt_left: &mut CrtCiphertext,
ctxt_right: &mut CrtCiphertext,
) -> CrtCiphertext {
// If the ciphertext cannot be added together without exceeding the capacity of a ciphertext
if !self.is_crt_sub_possible(ctxt_left, ctxt_right) {
rayon::join(
|| self.full_extract_parallelized(ctxt_left),
|| self.full_extract_parallelized(ctxt_right),
);
}
self.unchecked_crt_sub_parallelized(ctxt_left, ctxt_right)
}
/// Computes homomorphically the subtraction between ct_left and ct_right.
///
/// # Example
///
///```rust
/// use concrete_integer::gen_keys;
/// use concrete_shortint::parameters::PARAM_MESSAGE_2_CARRY_2;
///
/// // Generate the client key and the server key:
/// let (cks, sks) = gen_keys(&PARAM_MESSAGE_2_CARRY_2);
///
/// let clear_1 = 14;
/// let clear_2 = 5;
/// let basis = vec![2, 3, 5];
/// // Encrypt two messages
/// let mut ctxt_1 = cks.encrypt_crt(clear_1, basis.clone());
/// let mut ctxt_2 = cks.encrypt_crt(clear_2, basis.clone());
///
/// sks.smart_crt_sub_assign_parallelized(&mut ctxt_1, &mut ctxt_2);
///
/// // Decrypt
/// let res = cks.decrypt_crt(&ctxt_1);
/// assert_eq!((clear_1 - clear_2) % 30, res);
/// ```
pub fn smart_crt_sub_assign_parallelized(
&self,
ctxt_left: &mut CrtCiphertext,
ctxt_right: &mut CrtCiphertext,
) {
// If the ciphertext cannot be added together without exceeding the capacity of a ciphertext
if !self.is_crt_sub_possible(ctxt_left, ctxt_right) {
rayon::join(
|| self.full_extract_parallelized(ctxt_left),
|| self.full_extract_parallelized(ctxt_right),
);
}
self.unchecked_crt_sub_assign_parallelized(ctxt_left, ctxt_right);
}
}