Crate saber

This crate implements the Saber post-quantum key-encapsulation mechanism.

Saber is a post-quantum cryptographic key-encapsulation mechanism. It has been devised by:

• Jan-Pieter D'Anvers, KU Leuven, imec-COSIC
• Angshuman Karmakar, KU Leuven, imec-COSIC
• Sujoy Sinha Roy, KU Leuven, imec-COSIC
• Frederik Vercauteren, KU Leuven, imec-COSIC

Like many others, it is one of the round-2 candidates of the NIST Post-Quantum Cryptography "competition".

Getting started

Install this crate using Cargo by adding it to your dependencies:

[dependencies]
saber = { git = "https://github.com/dsprenkels/saber-rust" }

Then, choose one of the parameter sets by importing them into your code:

extern crate saber;

use saber::saber::{keygen, encapsulate, decapsulate};

Now you can use the functions keygen, encapsulate and decapsulate to agree on a shared secret key between two endpoints.

// Consider a server with a key pair
let server_secret_key = keygen();
let server_public_key = server_secret_key.public_key();

// Let a client encapsulate some shared secret for the server
let (client_secret, ciphertext) = encapsulate(&server_public_key);

// Have the server decrypt the ciphertext
let server_secret = decapsulate(&ciphertext, &server_secret_key);

assert_eq!(client_secret.as_slice(), server_secret.as_slice());

(De)serializing keys

Both PublicKey and SecretKey can be stored into arrays using PublicKey::to_bytes and SecretKey::to_bytes respectively. To load a key back from a &[u8] buffer, use PublicKey::from_bytes and SecretKey::from_bytes. For example:

let public_key = secret_key.public_key();

use saber::saber::{PublicKey, encapsulate};

// Store the public key
let public_key_bytes = public_key.to_bytes().into_bytes();
println!("Saber public key: {:02x?}", &public_key_bytes[..]);

// Lose the original public-key struct
drop(public_key);

// Reload the public key
let public_key = match PublicKey::from_bytes(&public_key_bytes) {
    Ok(pk) => pk,
    Err(err) => panic!("Error decoding public key: {}", err),
};

// Now you can use the key again for key encapsulation
let (client_secret, ciphertext) = encapsulate(&public_key);

Modules

firesaber	Saber key encapsulation using paranoid parameters.
lightsaber	Saber key encapsulation using lightweight parameters.
saber	Regular saber key encapsulation mechanism.

Enums

Error

Error type for the saber crate.