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Kem

dcrypt_api::traits::kem

Trait Kem 

Source 
pub trait Kem {
    type PublicKey: Clone + Serialize;
    type SecretKey: Zeroize + Clone + SerializeSecret;
    type SharedSecret: Zeroize + Clone + SerializeSecret;
    type Ciphertext: Clone + Serialize;
    type KeyPair: Clone;

    // Required methods
    fn name() -> &'static str;
    fn keypair<R: CryptoRng + RngCore>(rng: &mut R) -> Result<Self::KeyPair>;
    fn public_key(keypair: &Self::KeyPair) -> Self::PublicKey;
    fn secret_key(keypair: &Self::KeyPair) -> Self::SecretKey;
    fn encapsulate<R: CryptoRng + RngCore>(
        rng: &mut R,
        public_key: &Self::PublicKey,
    ) -> Result<(Self::Ciphertext, Self::SharedSecret)>;
    fn decapsulate(
        secret_key: &Self::SecretKey,
        ciphertext: &Self::Ciphertext,
    ) -> Result<Self::SharedSecret>;
}
Expand description

Trait for Key Encapsulation Mechanism (KEM) with domain-specific types.

§Security Design

This trait defines distinct types and explicit serialization contracts for KEM inputs and outputs. Implementations remain responsible for validating encodings and meeting their algorithm-specific security requirements.

Required Associated Types§

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type PublicKey: Clone + Serialize

Public key type with appropriate constraints.

§Security Note

Implements Serialize for the public encoding boundary.

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type SecretKey: Zeroize + Clone + SerializeSecret

Secret key type with an explicit clearing and serialization contract.

§Security Note
  • Implements Zeroize for best-effort clearing of owned initialized storage.
  • Implements SerializeSecret for exact-size protected exports.
Source

type SharedSecret: Zeroize + Clone + SerializeSecret

Shared-secret type with an explicit clearing and serialization contract.

§Security Note
  • Implements Zeroize for best-effort clearing of owned initialized storage.
  • Implements SerializeSecret for exact-size protected exports.
  • Should be converted to application keys immediately after generation.
Source

type Ciphertext: Clone + Serialize

Ciphertext type for the encapsulated key.

§Security Note

Implements Serialize for the public encoding boundary.

Source

type KeyPair: Clone

Keypair type for efficient storage of related keys. It is an intermediate type and does not require a serialization contract itself.

Required Methods§

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fn name() -> &'static str

Returns the KEM algorithm name.

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fn keypair<R: CryptoRng + RngCore>(rng: &mut R) -> Result<Self::KeyPair>

Generate a new keypair.

§Security Requirements
  • Must use the provided CSPRNG for all randomness.
  • Keys must be generated according to the algorithm specification.
Source

fn public_key(keypair: &Self::KeyPair) -> Self::PublicKey

Extract public key from keypair.

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fn secret_key(keypair: &Self::KeyPair) -> Self::SecretKey

Extract secret key from keypair.

§Security Note

The returned secret key should be protected and explicitly cleared after use.

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fn encapsulate<R: CryptoRng + RngCore>( rng: &mut R, public_key: &Self::PublicKey, ) -> Result<(Self::Ciphertext, Self::SharedSecret)>

Encapsulate a shared secret using the recipient’s public key.

§Security Requirements
  • Must validate the public key internally.
  • Must use fresh randomness from the provided RNG.
  • Must not intentionally branch or index memory on secret material. Concrete compiler/target behavior requires separate validation.
Source

fn decapsulate( secret_key: &Self::SecretKey, ciphertext: &Self::Ciphertext, ) -> Result<Self::SharedSecret>

Decapsulate a shared secret using the private key.

§Security Requirements
  • Must not intentionally branch or index memory on secret material. Concrete compiler/target behavior requires separate validation.
  • Should use implicit rejection for IND-CCA2 security where applicable.
  • Must not leak information about the secret key.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§