Crate sntrup 

Pure Rust implementation of Streamlined NTRU Prime KEM for all parameter sizes.

Streamlined NTRU Prime is a lattice-based, quantum-resistant cryptographic algorithm designed for secure key exchange. This crate supports all six parameter sets: sntrup653, sntrup761, sntrup857, sntrup953, sntrup1013, and sntrup1277.

Usage

use sntrup::{Sntrup761, SntrupKem};

let mut rng = rand::rng();
let (ek, dk) = Sntrup761::generate_key(&mut rng);
let (ct, ss1) = ek.encapsulate(&mut rng);
let ss2 = dk.decapsulate(&ct);
assert_eq!(ss1, ss2);

Security Levels

• Sntrup653 / sntrup653: NIST Level 1 (128-bit security) — research/testing only, prefer Sntrup761 or higher for production
• Sntrup761 / sntrup761: NIST Level 2 (128-bit+ security, used by OpenSSH)
• Sntrup857 / sntrup857: NIST Level 3 (192-bit security)
• Sntrup953 / sntrup953: NIST Level 4 (192-bit+ security)
• Sntrup1013 / sntrup1013: NIST Level 5 (256-bit security)
• Sntrup1277 / sntrup1277: NIST Level 5 (256-bit security, with extra margin)

Sizes (bytes)

Parameter Set	NIST Level	Public Key	Secret Key	Ciphertext	Shared Secret
sntrup653	1	994	1518	897	32
sntrup761	2	1158	1763	1039	32
sntrup857	3	1322	1999	1184	32
sntrup953	4	1505	2254	1349	32
sntrup1013	5	1623	2417	1455	32
sntrup1277	5	2067	3059	1847	32

Features

• kgen: Key generation (default)
• ecap: Encapsulation (default)
• dcap: Decapsulation (default)
• serde: Serde serialization support via serdect

Modules

sntrup653

sntrup653: NIST Level 1 (128-bit security), p=653, q=4621, w=288.

sntrup761

sntrup761: NIST Level 2 (128-bit+ security), p=761, q=4591, w=286. Used by OpenSSH.

sntrup857

sntrup857: NIST Level 3 (192-bit security), p=857, q=5167, w=322.

sntrup953

sntrup953: NIST Level 4 (192-bit+ security), p=953, q=6343, w=396.

sntrup1013

sntrup1013: NIST Level 5 (256-bit security), p=1013, q=7177, w=448.

sntrup1277

sntrup1277: NIST Level 5 (256-bit security, extra margin), p=1277, q=7879, w=492.

Structs

Ciphertext

Streamlined NTRU Prime ciphertext.

DecapsulationKey

Streamlined NTRU Prime decapsulation key (secret key).

EncapsulationKey

Streamlined NTRU Prime encapsulation key (public key).

SharedSecret

Streamlined NTRU Prime shared secret.

Sntrup653Params

sntrup653 parameter marker (NIST Level 1, 128-bit security).

Sntrup761Params

sntrup761 parameter marker (NIST Level 2, 128-bit+ security).

Sntrup857Params

sntrup857 parameter marker (NIST Level 3, 192-bit security).

Sntrup953Params

sntrup953 parameter marker (NIST Level 4, 192-bit+ security).

Sntrup1013Params

sntrup1013 parameter marker (NIST Level 5, 256-bit security).

Sntrup1277Params

sntrup1277 parameter marker (NIST Level 5, 256-bit security).

SntrupKem

Streamlined NTRU Prime Key Encapsulation Mechanism parameterized by parameter set.

Enums

Error

Errors returned by sntrup operations.

Traits

SntrupParams

Trait defining a Streamlined NTRU Prime parameter set.

Type Aliases

Sntrup653

sntrup653 KEM (NIST Level 1, 128-bit security).

Sntrup761

sntrup761 KEM (NIST Level 2, 128-bit+ security, used by OpenSSH).

Sntrup857

sntrup857 KEM (NIST Level 3, 192-bit security).

Sntrup953

sntrup953 KEM (NIST Level 4, 192-bit+ security).

Sntrup1013

sntrup1013 KEM (NIST Level 5, 256-bit security).

Sntrup1277

sntrup1277 KEM (NIST Level 5, 256-bit security).