Metadata-Version: 2.1
Name: umbral
Version: 0.1.2a1
Summary: NuCypher's Umbral Proxy Re-Encryption Implementation
Home-page: https://github.com/nucypher/pyUmbral
Author: NuCypher
Author-email: dev@nucypher.com
License: UNKNOWN
Description: .. role:: bash(code)
           :language: bash
        
        =========
        pyUmbral
        =========
        v0.1.2-alpha.1
        
        .. image:: https://circleci.com/gh/nucypher/pyUmbral/tree/master.svg?style=svg
            :target: https://circleci.com/gh/nucypher/pyUmbral/tree/master
        
        pyUmbral is a python implementation of David Nuñez's threshold proxy re-encryption scheme: Umbral_.
        Implemented with OpenSSL_ and Cryptography.io_, pyUmbral is a referential and open-source cryptography library
        extending the traditional cryptological narrative of "Alice and Bob" by introducing a new actor,
        *Ursula*, who has the ability to take secrets encrypted for Alice and *re-encrypt* them for Bob.
        
        .. _Umbral: https://github.com/nucypher/umbral-doc/blob/master/umbral-doc.pdf
        .. _Cryptography.io: https://cryptography.io/en/latest/
        .. _OpenSSL: https://www.openssl.org/
        
        Usage
        =====
        
        **Key Generation**
        
        .. code-block:: python
        
            from umbral import pre, keys, signing
        
            # Generate Umbral keys for Alice.
            alices_private_key = keys.UmbralPrivateKey.gen_key()
            alices_public_key = alices_private_key.get_pubkey()
        
            alices_signing_key = keys.UmbralPrivateKey.gen_key()
            alices_verifying_key = alices_signing_key.get_pubkey()
            alices_signer = signing.Signer(private_key=alices_signing_key)
        
            # Generate Umbral keys for Bob.
            bobs_private_key = keys.UmbralPrivateKey.gen_key()
            bobs_public_key = bobs_private_key.get_pubkey()
        
        
        **Encryption**
        
        .. code-block:: python
        
            # Encrypt data with Alice's public key.
            plaintext = b'Proxy Re-encryption is cool!'
            ciphertext, capsule = pre.encrypt(alices_public_key, plaintext)
        
            # Decrypt data with Alice's private key.
            cleartext = pre.decrypt(ciphertext=ciphertext, 
                                    capsule=capsule, 
                                    decrypting_key=alices_private_key)
        
        
        **Re-Encryption Key Fragments**
        
        .. code-block:: python
        
            # Alice generates "M of N" re-encryption key fragments (or "KFrags") for Bob.
            # In this example, 10 out of 20.
            kfrags = pre.generate_kfrags(delegating_privkey=alices_private_key,
                                         signer=alices_signer,
                                         receiving_pubkey=bobs_public_key,
                                         threshold=10,
                                         N=20)
        
        
        **Re-Encryption**
        
        .. code-block:: python
        
          # Several Ursulas perform re-encryption, and Bob collects the resulting `cfrags`.
          # He must gather at least `threshold` `cfrags` in order to activate the capsule.
        
          capsule.set_correctness_keys(delegating=alices_public_key,
                                       receiving=bobs_public_key,
                                       verifying=alices_verifying_key)
        
          cfrags = list()           # Bob's cfrag collection
          for kfrag in kfrags[:10]:
            cfrag = pre.reencrypt(kfrag=kfrag, capsule=capsule)
            cfrags.append(cfrag)    # Bob collects a cfrag
        
        
        **Decryption by Bob**
        
        .. code-block:: python
        
          # Bob activates and opens the capsule
          for cfrag in cfrags:
            capsule.attach_cfrag(cfrag)
        
          bob_cleartext = pre.decrypt(ciphertext=ciphertext, 
                                      capsule=capsule, 
                                      decrypting_key=bobs_private_key)
          assert bob_cleartext == plaintext
        
        See more detailed usage examples in the docs_ directory.
        
        .. _docs : https://github.com/nucypher/pyUmbral/tree/master/docs
        
        
        Quick Installation
        ==================
        
        To install pyUmbral, simply use `pip`:
        
        .. code-block:: bash
        
          $ pip3 install umbral
        
        
        Alternatively, you can checkout the repo and install it from there. 
        The NuCypher team uses pipenv for managing pyUmbral's dependencies.
        The recommended installation procedure is as follows:
        
        .. code-block:: bash
        
            $ sudo pip3 install pipenv
            $ pipenv install
        
        Post-installation, you can activate the project virtual environment
        in your current terminal session by running :bash:`pipenv shell`.
        
        For more information on pipenv, find the official documentation here: https://docs.pipenv.org/.
        
        
        Academic Whitepaper
        ====================
        
        The Umbral scheme academic whitepaper and cryptographic specifications
        are available on GitHub_.
        
          "Umbral: A Threshold Proxy Re-Encryption Scheme"
          *by David Nuñez*
          https://github.com/nucypher/umbral-doc/blob/master/umbral-doc.pdf
        
        .. _GitHub: https://github.com/nucypher/umbral-doc/
        
        
        Support & Contribute
        =====================
        
        - Issue Tracker: https://github.com/nucypher/pyUmbral/issues
        - Source Code: https://github.com/nucypher/pyUmbral
        
        OFAC Sanctions Disclaimer
        =========================
        
        By using this software, you hereby affirm you are not an individual or entity subject to economic sanctions administered by the U.S. Government or any other applicable authority, including but not limited to, sanctioned party lists administered by the U.S. Treasury Department’s Office of Foreign Assets Control (OFAC), the U.S. State Department, and the U.S. Commerce Department.  You further affirm you are not located in, or ordinarily resident in, any country, territory or region subject to comprehensive economic sanctions administered by OFAC, which are subject to change but currently include Cuba, Iran, North Korea, Syria and the Crimea region.
        
Platform: UNKNOWN
Classifier: Development Status :: 2 - Pre-Alpha
Classifier: Intended Audience :: Science/Research
Classifier: License :: OSI Approved :: GNU General Public License v3 (GPLv3)
Classifier: Natural Language :: English
Classifier: Programming Language :: Python :: Implementation
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Topic :: Scientific/Engineering
Requires-Python: >=3
Provides-Extra: benchmarks
Provides-Extra: docs
Provides-Extra: testing
