Struct FrodoKem 

pub struct FrodoKem { /* private fields */ }

FrodoKEM-1344-AES (security level 5).

FrodoKEM is a lattice-based KEM whose security relies on the plain Learning With Errors (LWE) problem — a far more conservative variant than the structured (module/ring) lattice assumptions used by ML-KEM. The 1344 variant targets NIST security level 5; the AES flavour uses AES in counter mode as its pseudo-random generator, which benefits from hardware AES-NI acceleration on most modern CPUs.

Sizes

Object	Bytes
Public key	21,520
Secret key	43,088
Ciphertext	21,632
Shared secret	32

Pros

• Based on plain (unstructured) LWE rather than module/ring variants — a more conservative assumption with a longer analysis history.
• No known algebraic attacks that exploit ring structure.
• AES variant is fast on hardware with AES-NI.
• Standardized by the French and Germans as their preferred PQC KEM because it is so conservative.

Cons

• Large public key and ciphertext (~21 KB each) — significantly larger than ML-KEM; unsuitable for protocols that must transmit both in every handshake without compression or caching.

Reuse

Construct once with FrodoKem::new and reuse across operations — each instance owns the underlying liboqs algorithm object, so reusing it avoids re-allocating that object on every encapsulation/decapsulation.

Implementations

impl FrodoKem

pub const PUBLIC_KEY_LEN: usize = 21_520

Length in bytes of a serialized public key.

pub const SECRET_KEY_LEN: usize = 43_088

Length in bytes of a serialized secret key.

pub const CIPHERTEXT_LEN: usize = 21_632

Length in bytes of a ciphertext.

pub const SHARED_SECRET_LEN: usize = 32

Length in bytes of the encapsulated shared secret.

pub fn new() -> Self

Construct a reusable FrodoKEM-1344-AES instance.

Infallible: FrodoKEM-1344-AES is always compiled in via the crate’s oqs feature set, so the underlying algorithm object can always be created.

pub fn keypair(&self) -> Result<(PublicKey, SecretKey)>

pub fn encapsulate( &self, public_key: &PublicKey, ) -> Result<(Ciphertext, SharedSecret)>

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

pub fn ciphertext_from_bytes(&self, bytes: &[u8]) -> Result<Ciphertext>

Reconstruct a ciphertext from its serialized bytes.

Returns Error::InvalidLength if bytes is not exactly CIPHERTEXT_LEN bytes long.

pub fn public_key_from_bytes(&self, bytes: &[u8]) -> Result<PublicKey>

Reconstruct a public key from its serialized bytes.

Returns Error::InvalidLength if bytes is not exactly PUBLIC_KEY_LEN bytes long.

pub fn secret_key_from_bytes(&self, bytes: &[u8]) -> Result<SecretKey>

Reconstruct a secret key from its serialized bytes.

Returns Error::InvalidLength if bytes is not exactly SECRET_KEY_LEN bytes long.

Trait Implementations

impl Default for FrodoKem

fn default() -> Self

Returns the “default value” for a type.