mirror of https://github.com/nucypher/pyUmbral.git
59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
#1
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# Sets a default curve (secp256k1)
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import random
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from umbral import umbral, keys, config
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config.set_default_curve()
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#2
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# Generate keys for Alice and Bob
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alice_priv_key = keys.UmbralPrivateKey.gen_key()
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alice_pub_key = alice_priv_key.get_pubkey()
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bob_priv_key = keys.UmbralPrivateKey.gen_key()
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bob_pub_key = bob_priv_key.get_pubkey()
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#3
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# Encrypt some data for Alice
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plaintext = b'Proxy Re-encryption is cool!!'
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alice_ciphertext, umbral_capsule = umbral.encrypt(alice_pub_key, plaintext)
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print(alice_ciphertext)
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#4
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# Decrypt data for Alice
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alice_decrypted_data = umbral.decrypt(umbral_capsule, alice_priv_key, alice_ciphertext, alice_pub_key)
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print(alice_decrypted_data)
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#5
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# Bob receives a capsule through a side channel (s3, ipfs, Google cloud, etc)
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bob_capsule = umbral_capsule
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#6
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# Attempt Bob's decryption (fail)
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try:
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fail_decrypted_data = umbral.decrypt(bob_capsule, bob_priv_key, alice_ciphertext, alice_pubkey)
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except:
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print("Decryption failed!")
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#7
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# Generate threshold split re-encryption keys via Shamir's Secret Sharing
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# verification not ready yet, don't store vKeys
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# Use Alice's private key, and Bob's public key.
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# Use a minimum threshold of 10, and create 20 total shares
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kfrags, _ = umbral.split_rekey(alice_priv_key, bob_pub_key, 10, 20)
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#8
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# Have Ursula perform re-encrypton.
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# Pick 10 random shares:
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rand_min_shares = random.sample(kfrags, 10)
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# Have Ursula re-encrypt the shares and attach them to the capsule:
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for kfrag in kfrags:
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cfrag = umbral.reencrypt(kfrag, umbral_capsule)
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bob_capsule.attach_cfrag(cfrag)
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#9
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# Bob reconstructs the capsule and decrypts the ciphertext:
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bob_plaintext = umbral.decrypt(bob_capsule, bob_priv_key, alice_ciphertext, alice_pub_key)
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print(bob_plaintext)
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