https://github.com/tonyo/pyope

Implementation of Boldyreva's symmetric order-preserving encryption in Python
https://github.com/tonyo/pyope

cryptography encryption python

Last synced: 6 days ago
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Implementation of Boldyreva's symmetric order-preserving encryption in Python

• Host: GitHub
• URL: https://github.com/tonyo/pyope
• Owner: tonyo
• License: mit
• Created: 2014-12-30T10:26:01.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2022-12-07T22:19:37.000Z (almost 2 years ago)
• Last Synced: 2024-06-19T23:17:47.280Z (5 months ago)
• Topics: cryptography, encryption, python
• Language: Python
• Homepage:
• Size: 54.7 KB
• Stars: 95
• Watchers: 6
• Forks: 18
• Open Issues: 3
• Metadata Files:
  • Readme: README.rst
  • Changelog: HISTORY.rst
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
pyope

=====

|PyPi version| |Travis build|

This is an implementation of Boldyreva symmetric `order-preserving encryption`_ scheme (`Boldyreva's paper`_).

Supported Python versions: 2.7 and 3.5+

**Disclaimer 1** This is an experimental implementation, which should be thoroughly reviewed and evaluated before using in production and/or sensitive applications.

**Disclaimer 2** The Boldyreva scheme is not a standardized algorithm, so there are no test vectors and fixed plaintext-ciphertext

mapping for a given key. It means that, generally speaking, a plaintext encrypted with the same key by two different versions of the package might not be equal to each other.

Installation

------------

.. code:: shell

  pip install pyope

Examples

--------------

Quick start

.. code:: python

  from pyope.ope import OPE

  random_key = OPE.generate_key()

  cipher = OPE(random_key)

  assert cipher.encrypt(1000) < cipher.encrypt(2000) < cipher.encrypt(3000)

  assert cipher.decrypt(cipher.encrypt(1337)) == 1337

You can specify input and output ranges. Otherwise, default input (0..2^15-1) and output (0..2^31-1) ranges are used.

.. code:: python

  from pyope.ope import OPE, ValueRange

  cipher = OPE(b'long key' * 2, in_range=ValueRange(-100, 100),

                                out_range=ValueRange(0, 9999))

  assert 0 < cipher.encrypt(10) < cipher.encrypt(42) < 9999

About order-preserving encryption

---------------------------------

Order-preserving encryption (OPE) allows to compare ciphertext values in order to learn the corresponding relation

between the underlying plaintexts. By definition, order-preserving encryption methods are **less secure** than

conventional encryption algorithms for the same data sizes, because the former leak ordering information of the plaintext 

values.

How can OPE be useful? For example, some systems may need OPE to perform a certain set of queries (such as range SQL

queries) over encrypted data. These systems include `CryptDB`_ and `Monomi`_ to name a few.

Security

--------

As mentioned above, security guarantees for Boldyreva's schema are weaker than those of deterministic encryption schemes,

but security can still be improved if the encryption keys are long enough. It is advised to use randomly generated keys at

least 256 bits long.

Running tests

-------------

PyTest is used as a test framework. Run all tests:

::

$ py.test tests/

TODO

----

- More tests

- Optimize performance

- Security guarantees?

.. |PyPi version| image:: https://img.shields.io/pypi/v/pyope.svg

   :target: https://pypi.python.org/pypi/pyope/

.. |Travis build| image:: https://travis-ci.org/tonyo/pyope.svg?branch=master

   :target: https://travis-ci.org/tonyo/pyope/

.. _order-preserving encryption: https://crypto.stackexchange.com/questions/3813/how-does-order-preserving-encryption-work

.. _Boldyreva's paper: http://www.cc.gatech.edu/~aboldyre/papers/bclo.pdf

.. _CryptDB: http://css.csail.mit.edu/cryptdb/

.. _Monomi: http://people.csail.mit.edu/nickolai/papers/tu-monomi.pdf