public void DecodeTest()
{
EncryptionParameters parms = new EncryptionParameters(SchemeType.BFV)
{
PlainModulus = new SmallModulus(1024)
};
SEALContext context = SEALContext.Create(parms);
IntegerEncoder encoder = new IntegerEncoder(context);
Plaintext plain = new Plaintext("0x^5 + 1x^4 + 1x^3 + 1x^1 + 0");
Assert.AreEqual(6ul, plain.CoeffCount);
ulong resultU64 = encoder.DecodeUInt64(plain);
Assert.AreEqual(26UL, resultU64);
long resultI64 = encoder.DecodeInt64(plain);
Assert.AreEqual(26L, resultI64);
uint resultU32 = encoder.DecodeUInt32(plain);
Assert.AreEqual(26U, resultU32);
int resultI32 = encoder.DecodeInt32(plain);
Assert.AreEqual(26, resultI32);
BigUInt bui = encoder.DecodeBigUInt(plain);
Assert.IsNotNull(bui);
Assert.AreEqual(0, bui.CompareTo(26ul));
}
static public List <List <long> > decryptValues(List <List <Ciphertext> > weihtedSums, SecretKey sk, SEALContext context)
{
List <List <long> > results = new List <List <long> >();
Decryptor decryptor = new Decryptor(context, sk);
IntegerEncoder encoder = new IntegerEncoder(context);
int sample_ind = 0;
foreach (List <Ciphertext> sample in weihtedSums)
{
List <long> resultsRow = new List <long>();
foreach (Ciphertext encryptedClassScore in sample)
{
Plaintext plainClassScore = new Plaintext();
if (decryptor.InvariantNoiseBudget(encryptedClassScore) == 0)
{
throw new Exception("Noise budget depleated in sample " + sample_ind + ". Aborting...");
}
decryptor.Decrypt(encryptedClassScore, plainClassScore);
long ClassScore = encoder.DecodeInt64(plainClassScore) / (1000 * 1000);
resultsRow.Add(ClassScore);
}
results.Add(resultsRow);
sample_ind++;
}
return(results);
}
public void DecodeTest()
{
IntegerEncoder encoder = new IntegerEncoder(GlobalContext.BFVContext);
Plaintext plain = new Plaintext("0x^5 + 1x^4 + 1x^3 + 1x^1 + 0");
Assert.AreEqual(6ul, plain.CoeffCount);
ulong resultU64 = encoder.DecodeUInt64(plain);
Assert.AreEqual(26UL, resultU64);
long resultI64 = encoder.DecodeInt64(plain);
Assert.AreEqual(26L, resultI64);
uint resultU32 = encoder.DecodeUInt32(plain);
Assert.AreEqual(26U, resultU32);
int resultI32 = encoder.DecodeInt32(plain);
Assert.AreEqual(26, resultI32);
BigUInt bui = encoder.DecodeBigUInt(plain);
Assert.IsNotNull(bui);
Assert.AreEqual(0, bui.CompareTo(26ul));
}
public static void ExampleParameterSelection()
{
PrintExampleBanner("Example: Automatic Parameter Selection");
/*
* Here we demonstrate the automatic parameter selection tool. Suppose we want to find parameters
* that are optimized in a way that allows us to evaluate the polynomial 42x^3-27x+1. We need to know
* the size of the input data, so let's assume that x is an integer with base-3 representation of length
* at most 10.
*/
Console.Write("Finding optimized parameters for computing 42x^3-27x+1 ... ");
var chooserEncoder = new ChooserEncoder();
var chooserEvaluator = new ChooserEvaluator();
/*
* First create a ChooserPoly representing the input data. You can think of this modeling a freshly
* encrypted cipheretext of a plaintext polynomial with length at most 10 coefficients, where the
* coefficients have absolute value at most 1.
*/
var cinput = new ChooserPoly(10, 1);
// Compute the first term
var ccubedInput = chooserEvaluator.Exponentiate(cinput, 3);
var cterm1 = chooserEvaluator.MultiplyPlain(ccubedInput, chooserEncoder.Encode(42));
// Compute the second term
var cterm2 = chooserEvaluator.MultiplyPlain(cinput, chooserEncoder.Encode(27));
// Subtract the first two terms
var csum12 = chooserEvaluator.Sub(cterm1, cterm2);
// Add the constant term 1
var cresult = chooserEvaluator.AddPlain(csum12, chooserEncoder.Encode(1));
// To find an optimized set of parameters, we use ChooserEvaluator.SelectParameters(...).
var optimalParms = new EncryptionParameters();
chooserEvaluator.SelectParameters(new List <ChooserPoly> {
cresult
}, 0, optimalParms);
// We still need to validate the returned parameters
optimalParms.Validate();
Console.WriteLine("done.");
// Let's print these to see what was recommended
Console.WriteLine("Selected parameters:");
Console.WriteLine("{{ poly_modulus: {0}", optimalParms.PolyModulus);
Console.WriteLine("{{ coeff_modulus: {0}", optimalParms.CoeffModulus);
Console.WriteLine("{{ plain_modulus: {0}", optimalParms.PlainModulus.ToDecimalString());
Console.WriteLine("{{ decomposition_bit_count: {0}", optimalParms.DecompositionBitCount);
Console.WriteLine("{{ noise_standard_deviation: {0}", optimalParms.NoiseStandardDeviation);
Console.WriteLine("{{ noise_max_deviation: {0}", optimalParms.NoiseMaxDeviation);
// Let's try to actually perform the homomorphic computation using the recommended parameters.
// Generate keys.
Console.WriteLine("Generating keys ...");
var generator = new KeyGenerator(optimalParms);
/*
* Need to generate one evaluation key because below we will use Evaluator.Exponentiate(...),
* which relinearizes after every multiplication it performs (see ExampleRelinearization()
* for more details.
*/
generator.Generate(1);
Console.WriteLine("... key generation completed");
var publicKey = generator.PublicKey;
var secretKey = generator.SecretKey;
var evaluationKeys = generator.EvaluationKeys;
// Create the encoding/encryption tools
var encoder = new IntegerEncoder(optimalParms.PlainModulus, 3);
var encryptor = new Encryptor(optimalParms, publicKey);
var evaluator = new Evaluator(optimalParms, evaluationKeys);
var decryptor = new Decryptor(optimalParms, secretKey);
// Now perform the computations on real encrypted data.
const int inputValue = 12345;
var plainInput = encoder.Encode(inputValue);
Console.WriteLine("Encoded {0} as polynomial {1}", inputValue, plainInput);
Console.Write("Encrypting ... ");
var input = encryptor.Encrypt(plainInput);
Console.WriteLine("done.");
// Compute the first term
Console.Write("Computing first term ... ");
var cubedInput = evaluator.Exponentiate(input, 3);
var term1 = evaluator.MultiplyPlain(cubedInput, encoder.Encode(42));
Console.WriteLine("done.");
// Compute the second term
Console.Write("Computing second term ... ");
var term2 = evaluator.MultiplyPlain(input, encoder.Encode(27));
Console.WriteLine("done.");
// Subtract the first two terms
Console.Write("Subtracting first two terms ... ");
var sum12 = evaluator.Sub(term1, term2);
Console.WriteLine("done.");
// Add the constant term 1
Console.Write("Adding one ... ");
var result = evaluator.AddPlain(sum12, encoder.Encode(1));
Console.WriteLine("done.");
// Decrypt and decode
Console.Write("Decrypting ... ");
var plainResult = decryptor.Decrypt(result);
Console.WriteLine("done.");
// Finally print the result
Console.WriteLine("Polynomial 42x^3-27x+1 evaluated at x=12345: {0}", encoder.DecodeInt64(plainResult));
// How much noise budget are we left with?
Console.WriteLine("Noise budget in result: {0} bits", decryptor.InvariantNoiseBudget(result));
}