Trait LweCiphertextEncryptionEngine 

pub trait LweCiphertextEncryptionEngine<SecretKey, Plaintext, Ciphertext>: AbstractEngine
where
    SecretKey: LweSecretKeyEntity,
    Plaintext: PlaintextEntity,
    Ciphertext: LweCiphertextEntity,
{
    // Required methods
    fn encrypt_lwe_ciphertext(
        &mut self,
        key: &SecretKey,
        input: &Plaintext,
        noise: Variance,
    ) -> Result<Ciphertext, LweCiphertextEncryptionError<Self::EngineError>>;
    unsafe fn encrypt_lwe_ciphertext_unchecked(
        &mut self,
        key: &SecretKey,
        input: &Plaintext,
        noise: Variance,
    ) -> Ciphertext;
}

A trait for engines encrypting LWE ciphertexts.

Semantics

This pure operation generates an LWE ciphertext containing the encryption of the input plaintext under the key secret key.

Formal Definition

LWE Encryption

inputs:

• $\mathsf{pt}\in\mathbb{Z}_q$: a plaintext
• $\vec{s}\in\mathbb{Z}_q^n$: a secret key
• $\mathcal{D_{\sigma^2,\mu}}$: a normal distribution of variance $\sigma^2$ and a mean $\mu$

outputs:

• $\mathsf{ct} = \left( \vec{a} , b\right) \in \mathsf{LWE}^n_{\vec{s}}( \mathsf{pt} )\subseteq \mathbb{Z}_q^{(n+1)}$: an LWE ciphertext

algorithm:

1. uniformly sample a vector $\vec{a}\in\mathbb{Z}_q^n$
2. sample an integer error term $e \hookleftarrow \mathcal{D_{\sigma^2,\mu}}$
3. compute $b = \left\langle \vec{a} , \vec{s} \right\rangle + \mathsf{pt} + e \in\mathbb{Z}_q$
4. output $\left( \vec{a} , b\right)$

Required Methods

fn encrypt_lwe_ciphertext( &mut self, key: &SecretKey, input: &Plaintext, noise: Variance, ) -> Result<Ciphertext, LweCiphertextEncryptionError<Self::EngineError>>

Encrypts an LWE ciphertext.

unsafe fn encrypt_lwe_ciphertext_unchecked( &mut self, key: &SecretKey, input: &Plaintext, noise: Variance, ) -> Ciphertext

Unsafely encrypts an LWE ciphertext.

Safety

For the general safety concerns regarding this operation, refer to the different variants of LweCiphertextEncryptionError. For safety concerns specific to an engine, refer to the implementer safety section.

Implementors

impl LweCiphertextEncryptionEngine<LweSecretKey32, Plaintext32, LweCiphertext32> for DefaultEngine

Description:

Implementation of LweCiphertextEncryptionEngine for DefaultEngine that operates on 32 bits integers.

impl LweCiphertextEncryptionEngine<LweSecretKey64, Plaintext64, LweCiphertext64> for DefaultEngine

Description:

Implementation of LweCiphertextEncryptionEngine for DefaultEngine that operates on 64 bits integers.