/// <summary>
/// Computes the multiplicative inverse of this <see cref="BigNumber" />
/// modulo <paramref name="modulo"/> and returns the result.
///
/// Precisely, computes <c>z</c> such that <c>x * z % m = 1</c>, where
/// <c>x</c> is the value of this <see cref="BigNumber" /> instance
/// and <c>m</c> the value of <paramref name="modulo"/>.
/// </summary>
/// <param name="modulo">The modulo for computing the multiplicative inverse.</param>
/// <returns>
/// A <see cref="BigNumber" /> instance with value<c>z</c>.
/// </returns>
public BigNumber ModReciprocal(BigNumber modulo)
{
using (var ctx = BigNumberContextHandle.CreateSecure())
{
var result = new BigNumber();
BigNumberHandle.ModInverse(result.Handle, Handle, modulo.Handle, ctx);
return(result);
}
}
/// <inheritdoc />
public ECPoint MultiplyScalar(ECPoint e, SecureBigNumber k)
{
using (var ctx = BigNumberContextHandle.CreateSecure())
{
var res = new ECPoint(Handle);
ECPointHandle.Multiply(Handle, res.Handle, BigNumberHandle.Null, e.Handle, k.Handle, ctx);
return(res);
}
}
/// <summary>
/// Computes this <see cref="BigNumber" /> to the power
/// of <paramref name="exponent"/> modulo <paramref name="modulo"/>
/// and returns the result.
///
/// Precisely, the returned value is <c>z = x^y % m</c>, where
/// <c>x</c> is the value of this <see cref="BigNumber" /> instance,
/// <c>y</c> the value of <paramref name="exponent"/> and <c>m</c> the
/// value of <paramref name="modulo"/>.
///
/// The computation is not secure. For a secure variant see
/// <see cref="BigNumber.ModExp(SecureBigNumber, BigNumber)" />.
/// </summary>
/// <param name="exponent">The exponent which to raise this <see cref="BigNumber" /> to.</param>
/// <param name="modulo">The modulo for the exponentiation.</param>
/// <returns>
/// A <see cref="BigNumber" /> instance with value<c>z</c>.
/// </returns>
public BigNumber ModExp(BigNumber exponent, BigNumber modulo)
{
using (var ctx = BigNumberContextHandle.CreateSecure())
{
var result = new BigNumber();
BigNumberHandle.ModExp(result.Handle, Handle, exponent.Handle, modulo.Handle, ctx);
return(result);
}
}
/// <inheritdoc />
public ECPoint GenerateElement(SecureBigNumber index)
{
using (var ctx = BigNumberContextHandle.CreateSecure())
{
var res = new ECPoint(Handle);
ECPointHandle.Multiply(Handle, res.Handle, index.Handle, ECPointHandle.Null, BigNumberHandle.Null, ctx);
return(res);
}
}