openfhe-python-fork/examples/pke/simple-integers-serial-bgvrns.py

# Initial Settings
from openfhe import *
# import openfhe.PKESchemeFeature as Feature

datafolder = 'demoData'
serType = BINARY # BINARY or JSON 
print("This program requres the subdirectory `" + datafolder + "' to exist, otherwise you will get an error writing serializations.")

# Sample Program: Step 1: Set CryptoContext
parameters = CCParamsBGVRNS()
parameters.SetPlaintextModulus(65537)
parameters.SetMultiplicativeDepth(2)

cryptoContext = GenCryptoContext(parameters)
# Enable features that you wish to use
cryptoContext.Enable(PKESchemeFeature.PKE)
cryptoContext.Enable(PKESchemeFeature.KEYSWITCH)
cryptoContext.Enable(PKESchemeFeature.LEVELEDSHE)

# Serialize cryptocontext
if not SerializeToFile(datafolder + "/cryptocontext.txt", cryptoContext, serType):
   raise Exception("Error writing serialization of the crypto context to cryptocontext.txt")
print("The cryptocontext has been serialized.")

# Sample Program: Step 2: Key Generation

# Generate a public/private key pair
keypair = cryptoContext.KeyGen()
print("The keypair has been generated.")

# Serialize the public key
if not SerializeToFile(datafolder + "/key-public.txt", keypair.publicKey, serType):
   raise Exception("Error writing serialization of the public key to key-public.txt")
print("The public key has been serialized.")

# Serialize the secret key
if not SerializeToFile(datafolder + "/key-private.txt", keypair.secretKey, serType):
   raise Exception("Error writing serialization of the secret key to key-private.txt")
print("The secret key has been serialized.")

# Generate the relinearization key
cryptoContext.EvalMultKeyGen(keypair.secretKey)
print("The relinearization key has been generated.")

# Serialize the relinearization key
if not cryptoContext.SerializeEvalMultKey(datafolder + "/key-eval-mult.txt",serType):
   raise Exception("Error writing serialization of the eval mult keys to \"key-eval-mult.txt\"")
print("The relinearization key has been serialized.")

# Generate the rotation evaluation keys
cryptoContext.EvalRotateKeyGen(keypair.secretKey, [1, 2, -1, -2])
print("The rotation evaluation keys have been generated.")

# Serialize the rotation evaluation keys
if not cryptoContext.SerializeEvalAutomorphismKey(datafolder + "/key-eval-rot.txt",serType):
   raise Exception("Error writing serialization of the eval rotate keys to \"key-eval-rot.txt\"")
print("The rotation evaluation keys have been serialized.")

# Sample Program: Step 3: Encryption

# First plaintext vector is encoded
vectorOfInts1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
plaintext1 = cryptoContext.MakePackedPlaintext(vectorOfInts1)

# Second plaintext vector is encoded
vectorOfInts2 = [3, 2, 1, 4, 5, 6, 7, 8, 9, 10, 11, 12]
plaintext2 = cryptoContext.MakePackedPlaintext(vectorOfInts2)

# Third plaintext vector is encoded
vectorOfInts3 = [1, 2, 5, 2, 5, 6, 7, 8, 9, 10, 11, 12]
plaintext3 = cryptoContext.MakePackedPlaintext(vectorOfInts3)


# The encoded vectors are encrypted
ciphertext1 = cryptoContext.Encrypt(keypair.publicKey, plaintext1)
ciphertext2 = cryptoContext.Encrypt(keypair.publicKey, plaintext2)
ciphertext3 = cryptoContext.Encrypt(keypair.publicKey, plaintext3)
print("The plaintexts have been encrypted.")

if not SerializeToFile(datafolder + "/ciphertext1.txt", ciphertext1, serType):
   raise Exception("Error writing serialization of ciphertext 1 to ciphertext1.txt")
print("The first ciphertext has been serialized.")

if not SerializeToFile(datafolder + "/ciphertext2.txt", ciphertext2, serType):
   raise Exception("Error writing serialization of ciphertext2 to ciphertext2.txt")
print("The second ciphertext has been serialized.")

if not SerializeToFile(datafolder + "/ciphertext3.txt", ciphertext3, serType):   
   raise Exception("Error writing serialization of ciphertext3 to ciphertext3.txt")
print("The third ciphertext has been serialized.")

# Sample Program: Step 4: Evaluation

# OpenFHE maintains an internal map of CryptoContext objects which are
# indexed by a tag and the tag is applied to both the CryptoContext and some
# of the keys. When deserializing a context, OpenFHE checks for the tag and
# if it finds it in the CryptoContext map, it will return the stored version.
# Hence, we need to clear the context and clear the keys.
cryptoContext.ClearEvalMultKeys()
cryptoContext.ClearEvalAutomorphismKeys()
ReleaseAllContexts()

# Deserialize the crypto context

cc, res = DeserializeCryptoContext(datafolder + "/cryptocontext.txt", serType)
if not res:
   raise Exception("Error reading serialization of the crypto context from cryptocontext.txt")
print("The cryptocontext has been deserialized.")

# Deserialize the public key
pk, res = DeserializePublicKey(datafolder + "/key-public.txt", serType)

if not res:
   raise Exception("Error reading serialization of the public key from key-public.txt")
print("The public key has been deserialized.")

if not cc.DeserializeEvalMultKey(datafolder + "/key-eval-mult.txt",serType):
   raise Exception("Could not deserialize the eval mult key file")

print("The relinearization key has been deserialized.")

if not cc.DeserializeEvalAutomorphismKey(datafolder + "/key-eval-rot.txt",serType):
   raise Exception("Could not deserialize the eval rotation key file")

print("Deserialized the eval rotation keys.")

# Deserialize the ciphertexts
ct1, res =  DeserializeCiphertext(datafolder + "/ciphertext1.txt", serType)

if not res:
    raise Exception("Could not read the ciphertext")
print("The first ciphertext has been deserialized.")

ct2, res = DeserializeCiphertext(datafolder + "/ciphertext2.txt", serType)

if not res:
    raise Exception("Could not read the ciphertext")
print("The second ciphertext has been deserialized.")

ct3, res = DeserializeCiphertext(datafolder + "/ciphertext3.txt", serType)
if not res:   
    raise Exception("Could not read the ciphertext")
print("The third ciphertext has been deserialized.")

# Homomorphic addition

ciphertextAdd12 = cc.EvalAdd(ct1, ct2)
ciphertextAddResult = cc.EvalAdd(ciphertextAdd12, ct3)

# Homomorphic multiplication
ciphertextMult12 = cc.EvalMult(ct1, ct2)
ciphertextMultResult = cc.EvalMult(ciphertextMult12, ct3)

# Homomorphic rotation
ciphertextRot1 = cc.EvalRotate(ct1, 1)
ciphertextRot2 = cc.EvalRotate(ct2, 2)
ciphertextRot3 = cc.EvalRotate(ct3, -1)
ciphertextRot4 = cc.EvalRotate(ct3, -2)

# Sample Program: Step 5: Decryption

sk, res = DeserializePrivateKey(datafolder + "/key-private.txt", serType)
if not res:
      raise Exception("Could not read secret key")
print("The secret key has been deserialized.")

# Decrypt the result of additions
plaintextAddResult = cc.Decrypt(sk, ciphertextAddResult)

# Decrypt the result of multiplications
plaintextMultResult = cc.Decrypt(sk, ciphertextMultResult)

# Decrypt the result of rotations
plaintextRot1 = cc.Decrypt(sk, ciphertextRot1)
plaintextRot2 = cc.Decrypt(sk, ciphertextRot2)
plaintextRot3 = cc.Decrypt(sk, ciphertextRot3)
plaintextRot4 = cc.Decrypt(sk, ciphertextRot4)

# Shows only the same number of elements as in the original plaintext vector
# By default it will show all coefficients in the BFV-encoded polynomial
plaintextRot1.SetLength(len(vectorOfInts1))
plaintextRot2.SetLength(len(vectorOfInts1))
plaintextRot3.SetLength(len(vectorOfInts1))
plaintextRot4.SetLength(len(vectorOfInts1))

# Output results
print("\nResults of homomorphic computations")
print("#1 + #2 + #3: " + str(plaintextAddResult))
print("#1 * #2 * #3: " + str(plaintextMultResult))
print("Left rotation of #1 by 1: " + str(plaintextRot1))
print("Left rotation of #1 by 2: " + str(plaintextRot2))
print("Right rotation of #1 by 1: " + str(plaintextRot3))
print("Right rotation of #1 by 2: " + str(plaintextRot4))