newhope-cffi 0.0.2

Tested, cross-platform Python 3 bindings for the NewHope key exchange mechanism supporting both NewHope1024-CPA-KEM and NewHope1024-CCA-KEM.

NewHope CFFI

NewHope is a key exchange protocol based on the Ring-Learning-with-Errors (Ring-LWE) problem and a round 2 candidate submission in the Post-Quantum Cryptography Standardization project organised by NIST.

This package provides tested, performant Python 3 CFFI bindings to the NewHope reference implementation with minor, cautious adjustments for cross-platform compatibility.

Installation

You can install this package using pip or the included setup.py script:

# Using pip
pip install newhope-cffi

# Using setup.py
python setup.py install

Usage

from newhope import generate_keypair, encrypt, decrypt
from secrets import compare_digest

# Alice generates a public key
public_key, secret_key = generate_keypair()

# Bob derives a secret (the plaintext) and encrypts it with Alice's public key to produce a ciphertext
ciphertext, plaintext_original = encrypt(public_key)

# Alice decrypts Bob's ciphertext to derive the now shared secret
plaintext_recovered = decrypt(secret_key, ciphertext)

# Compare the original and recovered secrets in constant time
assert compare_digest(plaintext_original, plaintext_recovered)

License

BSD 3-Clause License

Copyright (c) 2018, Phil Demetriou
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

* Neither the name of the copyright holder nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.