static SEALContext createContext(ulong keysize)
{
EncryptionParameters parms = new EncryptionParameters(SchemeType.BFV);
parms.PolyModulusDegree = keysize;
parms.CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: keysize);
parms.PlainModulus = new SmallModulus(1 << 8);
return(SEALContext.Create(parms));
}
public HomomorphicKeyManager()
{
EncryptionParameters parms = new EncryptionParameters(SchemeType.BFV);
parms.PolyModulusDegree = 2048;
parms.CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 2048);
parms.PlainModulus = new SmallModulus(1 << 8);
Context = SEALContext.Create(parms);
}
static GlobalContext()
{
EncryptionParameters encParams = new EncryptionParameters(SchemeType.BFV)
{
PolyModulusDegree = 4096,
CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 4096)
};
encParams.SetPlainModulus(0x133Ful);
Context = SEALContext.Create(encParams);
}
private SEALContext GetContext()
{
var parms = new EncryptionParameters();
parms.PolyModulus = "1x^2048 + 1";
parms.CoeffModulus = DefaultParams.CoeffModulus128(2048);
parms.PlainModulus = 1 << 8;
var context = new SEALContext(parms);
return(context);
}
public static SEALContext GetContext()
{
var encryptionParameters = new EncryptionParameters(SchemeType.BFV)
{
PolyModulusDegree = 32768,
CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 32768)
};
encryptionParameters.SetPlainModulus(0x133Ful);
Debug.WriteLine("[COMMON]: Successfully created context");
return(SEALContext.Create(encryptionParameters));
}
public void CoeffModulusTest()
{
EncryptionParameters encParams = new EncryptionParameters(SchemeType.BFV);
Assert.IsNotNull(encParams);
Assert.AreEqual(4, encParams.ParmsId.Block.Length);
List <SmallModulus> coeffs = new List <SmallModulus>(encParams.CoeffModulus);
Assert.IsNotNull(coeffs);
Assert.AreEqual(0, coeffs.Count);
coeffs = new List <SmallModulus>(DefaultParams.CoeffModulus128(4096));
encParams.CoeffModulus = coeffs;
List <SmallModulus> newCoeffs = new List <SmallModulus>(encParams.CoeffModulus);
Assert.IsNotNull(newCoeffs);
Assert.AreEqual(2, newCoeffs.Count);
Assert.AreEqual(0x007fffffff380001ul, newCoeffs[0].Value);
Assert.AreEqual(0x003fffffff000001ul, newCoeffs[1].Value);
}
public void Coeffs128Test()
{
List <SmallModulus> coeffs = new List <SmallModulus>(DefaultParams.CoeffModulus128(4096));
Assert.IsNotNull(coeffs);
Assert.AreEqual(2, coeffs.Count);
Assert.AreEqual(0x007fffffff380001ul, coeffs[0].Value);
Assert.AreEqual(0x003fffffff000001ul, coeffs[1].Value);
coeffs = new List <SmallModulus>(DefaultParams.CoeffModulus128(16384));
Assert.IsNotNull(coeffs);
Assert.AreEqual(8, coeffs.Count);
Assert.AreEqual(0x007fffffff380001ul, coeffs[0].Value);
Assert.AreEqual(0x007ffffffef00001ul, coeffs[1].Value);
Assert.AreEqual(0x007ffffffeac0001ul, coeffs[2].Value);
Assert.AreEqual(0x007ffffffe700001ul, coeffs[3].Value);
Assert.AreEqual(0x007ffffffe600001ul, coeffs[4].Value);
Assert.AreEqual(0x007ffffffe4c0001ul, coeffs[5].Value);
Assert.AreEqual(0x003fffffff000001ul, coeffs[6].Value);
Assert.AreEqual(0x003ffffffef40001ul, coeffs[7].Value);
}
public void ExpandModChainTest()
{
EncryptionParameters parms = new EncryptionParameters(SchemeType.BFV)
{
PolyModulusDegree = 4096,
CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 4096),
PlainModulus = new SmallModulus(1 << 20)
};
SEALContext context1 = SEALContext.Create(parms);
// By default there is a chain
SEALContext.ContextData contextData = context1.FirstContextData;
Assert.IsNotNull(contextData);
Assert.IsNotNull(contextData.NextContextData);
// This should not create a chain
SEALContext context2 = SEALContext.Create(parms, expandModChain: false);
contextData = context2.FirstContextData;
Assert.IsNotNull(contextData);
Assert.IsNull(contextData.NextContextData);
}
public void PropertiesTest()
{
SEALContext context = GlobalContext.Context;
Assert.IsTrue(context.FirstContextData.Qualifiers.ParametersSet);
Assert.IsFalse(context.FirstContextData.Qualifiers.UsingBatching);
Assert.IsTrue(context.FirstContextData.Qualifiers.UsingFastPlainLift);
Assert.IsTrue(context.FirstContextData.Qualifiers.UsingFFT);
Assert.IsTrue(context.FirstContextData.Qualifiers.UsingHEStdSecurity);
Assert.IsTrue(context.FirstContextData.Qualifiers.UsingNTT);
EncryptionParameters parms = new EncryptionParameters(SchemeType.CKKS)
{
PolyModulusDegree = 4096,
CoeffModulus = DefaultParams.CoeffModulus128(4096)
};
SEALContext context2 = SEALContext.Create(parms);
Assert.IsTrue(context2.FirstContextData.Qualifiers.ParametersSet);
Assert.IsTrue(context2.FirstContextData.Qualifiers.UsingBatching);
Assert.IsFalse(context2.FirstContextData.Qualifiers.UsingFastPlainLift);
Assert.IsTrue(context2.FirstContextData.Qualifiers.UsingFFT);
Assert.IsTrue(context2.FirstContextData.Qualifiers.UsingHEStdSecurity);
Assert.IsTrue(context2.FirstContextData.Qualifiers.UsingNTT);
EncryptionParameterQualifiers qualifiers = new EncryptionParameterQualifiers(context2.FirstContextData.Qualifiers);
Assert.IsNotNull(qualifiers);
Assert.IsTrue(qualifiers.ParametersSet);
Assert.IsTrue(qualifiers.UsingBatching);
Assert.IsFalse(qualifiers.UsingFastPlainLift);
Assert.IsTrue(qualifiers.UsingFFT);
Assert.IsTrue(qualifiers.UsingHEStdSecurity);
Assert.IsTrue(qualifiers.UsingNTT);
}
private static void HomoExample()
{
EncryptionParameters parms = new EncryptionParameters(SchemeType.BFV);
parms.PolyModulusDegree = 2048;
parms.CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 2048);
parms.PlainModulus = new SmallModulus(1 << 8);
SEALContext context = SEALContext.Create(parms);
IntegerEncoder encoder = new IntegerEncoder(context);
KeyGenerator keygen = new KeyGenerator(context);
Microsoft.Research.SEAL.PublicKey publicKey = keygen.PublicKey;
SecretKey secretKey = keygen.SecretKey;
Encryptor encryptor = new Encryptor(context, publicKey);
Evaluator evaluator = new Evaluator(context);
Decryptor decryptor = new Decryptor(context, secretKey);
int value1 = 5;
Plaintext plain1 = encoder.Encode(value1);
Console.WriteLine($"Encoded {value1} as polynomial {plain1.ToString()} (plain1)");
int value2 = -7;
Plaintext plain2 = encoder.Encode(value2);
Console.WriteLine($"Encoded {value2} as polynomial {plain2.ToString()} (plain2)");
Ciphertext encrypted1 = new Ciphertext();
Ciphertext encrypted2 = new Ciphertext();
Console.Write("Encrypting plain1: ");
encryptor.Encrypt(plain1, encrypted1);
Console.WriteLine("Done (encrypted1)");
Plaintext plainResult = new Plaintext();
decryptor.Decrypt(encrypted1, plainResult);
Console.WriteLine(encoder.DecodeInt32(plainResult));
Console.Write("Encrypting plain2: ");
encryptor.Encrypt(plain2, encrypted2);
Console.WriteLine("Done (encrypted2)");
Console.WriteLine($"Noise budget in encrypted1: {decryptor.InvariantNoiseBudget(encrypted1)} bits");
Console.WriteLine($"Noise budget in encrypted2: {decryptor.InvariantNoiseBudget(encrypted2)} bits");
evaluator.NegateInplace(encrypted1);
Console.WriteLine($"Noise budget in -encrypted1: {decryptor.InvariantNoiseBudget(encrypted1)} bits");
evaluator.AddInplace(encrypted1, encrypted2);
Console.WriteLine($"Noise budget in -encrypted1 + encrypted2: {decryptor.InvariantNoiseBudget(encrypted1)} bits");
evaluator.MultiplyInplace(encrypted1, encrypted2);
Console.WriteLine($"Noise budget in (-encrypted1 + encrypted2) * encrypted2: {decryptor.InvariantNoiseBudget(encrypted1)} bits");
plainResult = new Plaintext();
Console.Write("Decrypting result: ");
decryptor.Decrypt(encrypted1, plainResult);
Console.WriteLine("Done");
Console.WriteLine($"Plaintext polynomial: {plainResult.ToString()}");
Console.WriteLine($"Decoded integer: {encoder.DecodeInt32(plainResult)}");
}
public void TestLinearRegression_Encryption()
{
// these are the feature sets we will be encrypting and getting
// the ML model results on. The plaintext versions of these values
// should (in the encryped scheme) not be known by the evaluator
double[][] testX = new double[6][];
testX[0] = new double[] { 43.45089541, 53.15091973, 53.07708932, 93.65456934, 65.23330105, 69.34856259, 62.91649012, 35.28814156, 108.1002775, 100.1735266 };
testX[1] = new double[] { 51.59952075, 99.48561775, 95.75948428, 126.6533636, 142.5235433, 90.97955769, 43.66586306, 85.31957886, 62.57644682, 66.12458533 };
testX[2] = new double[] { 94.77026243, 71.51229208, 85.33271407, 69.58347566, 107.8693045, 101.6701889, 89.88200921, 54.93440139, 105.5448532, 72.07947083 };
testX[3] = new double[] { 89.53820766, 100.199631, 86.19911875, 85.88717675, 33.92249944, 80.47113937, 65.34411148, 89.70004394, 75.00778202, 122.3514331 };
testX[4] = new double[] { 96.86101454, 97.54597612, 122.9960987, 86.1281547, 115.5539807, 107.888993, 65.51660154, 74.17007885, 48.04727402, 93.56952259 };
testX[5] = new double[] { 91.75121904, 121.2115065, 62.92763365, 99.4343452, 70.420912, 88.0580948, 71.82993308, 80.49171244, 87.11321454, 100.1459868 };
// setup the encryptor and other various components
EncryptionParameters parms = new EncryptionParameters(SchemeType.CKKS);
parms.PolyModulusDegree = 8192;
parms.CoeffModulus = DefaultParams.CoeffModulus128(polyModulusDegree: 8192);
SEALContext context = SEALContext.Create(parms);
CKKSEncoder encoder = new CKKSEncoder(context);
KeyGenerator keygen = new KeyGenerator(context);
PublicKey publicKey = keygen.PublicKey;
SecretKey secretKey = keygen.SecretKey;
RelinKeys relinKeys = keygen.RelinKeys(decompositionBitCount: DefaultParams.DBCmax);
Encryptor encryptor = new Encryptor(context, publicKey);
Evaluator evaluator = new Evaluator(context);
Decryptor decryptor = new Decryptor(context, secretKey);
double scale = Math.Pow(2.0, 30);
List <List <Ciphertext> > featureCiphers = new List <List <Ciphertext> >();
for (int i = 0; i < testX.Length; i++)
{
List <Ciphertext> curFeatureCiphers = new List <Ciphertext>();
foreach (var featureVal in testX[i])
{
List <double> featureVector = new double[] { featureVal }.ToList();
Plaintext plain = new Plaintext();
encoder.Encode(featureVal, scale, plain);
Ciphertext encrypted = new Ciphertext();
encryptor.Encrypt(plain, encrypted);
curFeatureCiphers.Add(encrypted);
}
featureCiphers.Add(curFeatureCiphers);
}
// This is the 'evaluator' section
// this is not a part of the client and would, in a cloud based solution, be run on the server
// the server should not know the values of the input features, but it will do math on them
// likewise, the client would not know the various weights and parameters, but will receive a result
double[] weights_model =
{ 0.0921533,
0.14545279,
0.11066622,
0.06119513,
0.10041948,
0.19091597,
0.07359407,
0.04503237,
0.10848583,
0.10092494 };
double intercept_model = -2.484390163425502;
double[] weights_groundTruth =
{ 0.1, 0.15, 0.1, 0.05, 0.1, 0.2, 0.05, 0.05, 0.1, 0.1 };
// we need to encode the weights/parameters/intercepts/etc. used by the model using the same public key as the client
List <Ciphertext> weightsCTs = new List <Ciphertext>();
List <Ciphertext> scoreCTs = new List <Ciphertext>();
foreach (var weight in weights_model)
{
List <double> weightVector = new double[] { weight }.ToList();
List <double> scoreVector = new double[] { 0.0 }.ToList();
Plaintext weightPT = new Plaintext();
encoder.Encode(weight, scale, weightPT);
Ciphertext weightCT = new Ciphertext();
encryptor.Encrypt(weightPT, weightCT);
weightsCTs.Add(weightCT);
}
// next, we run the actual model's computation
// linear regression is a basic dot product
for (int i = 0; i < featureCiphers.Count(); i++)
{
List <Ciphertext> multResultCTs = new List <Ciphertext>();
for (var j = 0; j < weightsCTs.Count; j++)
{
Ciphertext multResultCT = new Ciphertext();
evaluator.Multiply(weightsCTs[j], featureCiphers[i][j], multResultCT);
multResultCTs.Add(multResultCT);
}
Ciphertext dotProductResult = new Ciphertext();
evaluator.AddMany(multResultCTs, dotProductResult);
Plaintext scorePT = new Plaintext();
encoder.Encode(intercept_model, dotProductResult.Scale, scorePT);
Ciphertext scoreCT = new Ciphertext();
encryptor.Encrypt(scorePT, scoreCT);
evaluator.AddInplace(scoreCT, dotProductResult);
scoreCTs.Add(scoreCT);
//evaluator.AddInplace(scoreCTs[i], interceptCT);
}
// we now have the encrypted version of the ML model. The below section is the client's again
// in it, we decrypt the results given by the server using the private key generated previously
List <List <double> > predictions = new List <List <double> >();
for (int i = 0; i < scoreCTs.Count; i++)
{
Plaintext plainResult = new Plaintext();
var encryptedResult = scoreCTs[i];
decryptor.Decrypt(encryptedResult, plainResult);
List <double> result = new List <double>();
encoder.Decode(plainResult, result);
predictions.Add(result);
}
// this is the output section. In practice, we would not have access to these values (as they represent the ground truth)
// We are using them here merely to demonstrate that we can properly recover the proper ML model output
double[] yGroundTruth = { 68.43881952, 87.75905253, 88.34053641, 83.87264322, 95.20322583, 89.61704108 };
double[] yTest = { 68.702934, 87.28860458, 88.40827187, 83.24001674, 94.53137951, 89.00229455 };
const double EPSILON = 1e-4;
for (int i = 0; i < predictions.Count; i++)
{
var avgDecryption = predictions[i].Average();
var absDelta = Math.Abs(avgDecryption - yTest[i]);
Assert.IsTrue(absDelta < EPSILON);
}
}
public void Coeffs128FailTest()
{
IEnumerable <SmallModulus> coeffs = DefaultParams.CoeffModulus128(1030);
}