public void DivideTest()
{
ParameterSet parameters = ECParameterSets.ParamSet_EC_P256_V1;
for (int i = 0; i < 10; ++i)
{
FieldZqElement a = parameters.Group.FieldZq.GetRandomElement(false);
FieldZqElement b = parameters.Group.FieldZq.GetRandomElement(true);
FieldZqElement c = a.Divide(b);
Assert.AreEqual <FieldZqElement>(a * b.Invert(), c, "a.divide(b).");
FieldZqElement d = a / b;
Assert.AreEqual <FieldZqElement>(c, d, "a / b");
}
FieldZq Zq = FieldZq.CreateFieldZq(new byte[] { 0x05 });
Assert.AreEqual <FieldZqElement>(Zq.GetElement(4), Zq.GetElement(2) / Zq.GetElement(3), "2/3 = 4");
Assert.AreEqual <FieldZqElement>(Zq.GetElement(4), Zq.GetElement(1) / Zq.GetElement(4), "1/4 = 4");
Assert.AreEqual <FieldZqElement>(Zq.GetElement(1), Zq.GetElement(2) / Zq.GetElement(2), "2/3 = 1");
}
/// <summary>
/// Constructs a new <code>Prover</code> instance.
/// </summary>
/// <param name="ip">The Issuer parameters.</param>
/// <param name="numberOfTokens">Number of tokens to issue.</param>
/// <param name="gamma">The gamma value encoding the token attributes. If <c>beta0</c> is non-null, then this value is blinded with <c>beta0</c>.</param>
/// <param name="TI">The token information field value.</param>
/// <param name="PI">The Prover information field value.</param>
/// <param name="preGeneratedRandomData">Optional pregenerated ProverRandomData instance.</param>
/// <param name="isDeviceProtected">True if the token is to be device-protected, false otherwise.</param>
/// <param name="batchValidationSecurityLevel">The security level of the batch token signature validation. Given a security level <code>l</code>,
/// the probability for the Prover to accept an invalid token is <code>2^-l</code>. If set to 0, than
/// regular validation is used. A value of 20 is recommended.</param>
/// <param name="beta0">Non-null if the input <c>gamma</c> value is blinded (collaborative issuance, i.e., the input <c>gamma</c> is blinded with beta0).
/// This parameter defaults to null if ommitted. </param>
internal Prover(IssuerParameters ip, int numberOfTokens, GroupElement gamma, byte[] TI, byte[] PI, ProverRandomData preGeneratedRandomData,
bool isDeviceProtected, ushort batchValidationSecurityLevel, FieldZqElement beta0 = null)
{
if (ip == null)
{
throw new ArgumentNullException("ip");
}
this.ip = ip;
if (numberOfTokens <= 0)
{
throw new ArgumentException("numberOfTokens must be greater than 0");
}
this.numberOfTokens = numberOfTokens;
this.TI = TI;
this.PI = PI;
if (preGeneratedRandomData != null &&
(preGeneratedRandomData.Alpha.Length != numberOfTokens ||
preGeneratedRandomData.Beta1.Length != numberOfTokens ||
preGeneratedRandomData.Beta2.Length != numberOfTokens))
{
throw new ArgumentException("invalid preGeneratedRandomData");
}
this.isDeviceProtected = isDeviceProtected;
this.batchValidationSecurityLevel = batchValidationSecurityLevel;
this.gamma = gamma;
if (beta0 != null) // inputs are blinded; collab issuance
{
this.beta0Inverse = beta0.Invert();
}
else // no collab issuance
{
this.beta0Inverse = ip.Zq.One;
}
Precompute(gamma, preGeneratedRandomData);
}