Enum EncapsulationPrivateKey

pub enum EncapsulationPrivateKey {
    X25519(X25519PrivateKey),
    MLKEM(MLKEMPrivateKey),
}

A private key used for key encapsulation mechanisms (KEM).

EncapsulationPrivateKey is an enum representing different types of private keys that can be used for key encapsulation, including:

• X25519: Curve25519-based key exchange
• ML-KEM: Module Lattice-based Key Encapsulation Mechanism at various security levels

These private keys are used to decrypt (decapsulate) shared secrets that have been encapsulated with the corresponding public keys.

Variants

X25519(X25519PrivateKey)

An X25519 private key

MLKEM(MLKEMPrivateKey)

An ML-KEM private key (post-quantum)

Implementations

impl EncapsulationPrivateKey

pub fn encapsulation_scheme(&self) -> EncapsulationScheme

Returns the encapsulation scheme associated with this private key.

Returns

The encapsulation scheme (X25519, MLKEM512, MLKEM768, or MLKEM1024) that corresponds to this private key.

Example

use bc_components::{
    EncapsulationPrivateKey, EncapsulationScheme, X25519PrivateKey,
};

let x25519_private_key = X25519PrivateKey::new();
let encapsulation_private_key =
    EncapsulationPrivateKey::X25519(x25519_private_key);
assert_eq!(
    encapsulation_private_key.encapsulation_scheme(),
    EncapsulationScheme::X25519
);

pub fn decapsulate_shared_secret( &self, ciphertext: &EncapsulationCiphertext, ) -> Result<SymmetricKey, Error>

Decapsulates a shared secret from a ciphertext using this private key.

This method performs the decapsulation operation for key exchange. It takes an EncapsulationCiphertext and extracts the shared secret that was encapsulated using the corresponding public key.

Parameters

• ciphertext - The encapsulation ciphertext containing the encapsulated shared secret

Returns

A Result containing the decapsulated SymmetricKey if successful, or an error if the decapsulation fails or if the ciphertext type doesn’t match the private key type.

Errors

Returns an error if:

• The ciphertext type doesn’t match the private key type
• The decapsulation operation fails

Example

use bc_components::EncapsulationScheme;

// Generate a key pair
let (private_key, public_key) = EncapsulationScheme::default().keypair();

// Encapsulate a new shared secret using the public key
let (secret1, ciphertext) = public_key.encapsulate_new_shared_secret();

// Decapsulate the shared secret using the private key
let secret2 = private_key.decapsulate_shared_secret(&ciphertext).unwrap();

// The original and decapsulated secrets should match
assert_eq!(secret1, secret2);

Trait Implementations

impl Clone for EncapsulationPrivateKey

fn clone(&self) -> EncapsulationPrivateKey

Returns a duplicate of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for EncapsulationPrivateKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Decrypter for EncapsulationPrivateKey

Implementation of the Decrypter trait for EncapsulationPrivateKey.

This allows EncapsulationPrivateKey to be used with the generic decryption interface defined by the Decrypter trait.

fn encapsulation_private_key(&self) -> EncapsulationPrivateKey

Returns the encapsulation private key for this decrypter.

fn decapsulate_shared_secret( &self, ciphertext: &EncapsulationCiphertext, ) -> Result<SymmetricKey, Error>

Decapsulates a shared secret from a ciphertext.

impl From<EncapsulationPrivateKey> for CBOR

Conversion from EncapsulationPrivateKey to CBOR for serialization.

fn from(private_key: EncapsulationPrivateKey) -> CBOR

Converts to this type from the input type.

impl Hash for EncapsulationPrivateKey

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for EncapsulationPrivateKey

fn eq(&self, other: &EncapsulationPrivateKey) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TryFrom<CBOR> for EncapsulationPrivateKey

Conversion from CBOR to EncapsulationPrivateKey for deserialization.

type Error = Error

The type returned in the event of a conversion error.

fn try_from(cbor: CBOR) -> Result<EncapsulationPrivateKey, Error>

Performs the conversion.

impl Eq for EncapsulationPrivateKey

impl StructuralPartialEq for EncapsulationPrivateKey