/// <summary>
/// Compare this polynomial to another for equality
/// </summary>
///
/// <param name="Obj">Object to compare</param>
///
/// <returns>True if equal, otherwise false</returns>
public override bool Equals(Object Obj)
{
if (this == Obj)
{
return(true);
}
if (Obj == null)
{
return(false);
}
SparseTernaryPolynomial other = (SparseTernaryPolynomial)Obj;
if (_N != other._N)
{
return(false);
}
if (!Compare.AreEqual(_negOnes, other._negOnes))
{
return(false);
}
if (!Compare.AreEqual(_ones, other._ones))
{
return(false);
}
return(true);
}
/// <summary>
/// Generates a "sparse" or "dense" polynomial containing numOnes ints equal to 1,
/// numNegOnes int equal to -1, and the rest equal to 0.
/// </summary>
///
/// <param name="N">Number of coeffeients</param>
/// <param name="NumOnes">Number of ones</param>
/// <param name="NumNegOnes">Number of negative ones</param>
/// <param name="Sparse">Create a SparseTernaryPolynomial or DenseTernaryPolynomial</param>
/// <param name="Rng">Random number generator</param>
///
/// <returns>A ternary polynomial</returns>
public static ITernaryPolynomial GenerateRandomTernary(int N, int NumOnes, int NumNegOnes, bool Sparse, IRandom Rng)
{
if (Sparse)
{
return(SparseTernaryPolynomial.GenerateRandom(N, NumOnes, NumNegOnes, Rng));
}
else
{
return(DenseTernaryPolynomial.GenerateRandom(N, NumOnes, NumNegOnes, Rng));
}
}
/// <summary>
/// Generates a <c>ProductFormPolynomial</c> from three random ternary polynomials.
/// </summary>
///
/// <param name="N">Number of coefficients</param>
/// <param name="Df1">Number of ones in the first polynomial; also the number of negative ones</param>
/// <param name="Df2">Number of ones in the second polynomial; also the number of negative ones</param>
/// <param name="Df3Ones">Number of ones in the third polynomial</param>
/// <param name="Df3NegOnes">Number of negative ones in the third polynomial</param>
/// <param name="Rng">Random number generator</param>
///
/// <returns>A random <c>ProductFormPolynomial</c></returns>
public static ProductFormPolynomial GenerateRandom(int N, int Df1, int Df2, int Df3Ones, int Df3NegOnes, IRandom Rng)
{
SparseTernaryPolynomial f1 = null;
SparseTernaryPolynomial f2 = null;
SparseTernaryPolynomial f3 = null;
f1 = SparseTernaryPolynomial.GenerateRandom(N, Df1, Df1, Rng);
f2 = SparseTernaryPolynomial.GenerateRandom(N, Df2, Df2, Rng);
f3 = SparseTernaryPolynomial.GenerateRandom(N, Df3Ones, Df3NegOnes, Rng);
return(new ProductFormPolynomial(f1, f2, f3));
}
/// <summary>
/// Decodes a polynomial encoded with ToBinary()
/// </summary>
///
/// <param name="InputStrem">An input stream containing an encoded polynomial</param>
/// <param name="N">Number of coefficients in the polynomial</param>
///
/// <returns>The decoded polynomial</returns>
public static ProductFormPolynomial FromBinary(MemoryStream InputStrem, int N)
{
SparseTernaryPolynomial f1;
try
{
f1 = SparseTernaryPolynomial.FromBinary(InputStrem, N);
SparseTernaryPolynomial f2 = SparseTernaryPolynomial.FromBinary(InputStrem, N);
SparseTernaryPolynomial f3 = SparseTernaryPolynomial.FromBinary(InputStrem, N);
return(new ProductFormPolynomial(f1, f2, f3));
}
catch (IOException ex)
{
throw new NTRUException("ProductFormPolynomial:FromBinary", ex.Message, ex);
}
}
/// <summary>
/// Constructs a new polynomial from three sparsely populated ternary polynomials
/// </summary>
///
/// <param name="F1">F1 polynomial</param>
/// <param name="F2">F2 polynomial</param>
/// <param name="F3">F3 polynomial</param>
public ProductFormPolynomial(SparseTernaryPolynomial F1, SparseTernaryPolynomial F2, SparseTernaryPolynomial F3)
{
this._f1 = F1;
this._f2 = F2;
this._f3 = F3;
}
/// <summary>
/// Read a Private key from a stream
/// </summary>
///
/// <param name="KeyStream">The stream containing the key</param>
///
/// <returns>An initialized NTRUPrivateKey class</returns>
///
/// <exception cref="NTRUException">Thrown if the stream can not be read</exception>
public static NTRUPrivateKey From(MemoryStream KeyStream)
{
BinaryReader dataStream = new BinaryReader(KeyStream);
try
{
// ins.Position = 0; wrong here, ins pos is wrong
int n = IntUtils.ReadShort(KeyStream);
int q = IntUtils.ReadShort(KeyStream);
byte flags = dataStream.ReadByte();
bool sparse = (flags & 1) != 0;
bool fastFp = (flags & 2) != 0;
IPolynomial t;
TernaryPolynomialType polyType = (flags & 4) == 0 ?
TernaryPolynomialType.SIMPLE :
TernaryPolynomialType.PRODUCT;
if (polyType == TernaryPolynomialType.PRODUCT)
{
t = ProductFormPolynomial.FromBinary(KeyStream, n);
}
else
{
IntegerPolynomial fInt = IntegerPolynomial.FromBinary3Tight(KeyStream, n);
if (sparse)
t = new SparseTernaryPolynomial(fInt);
else
t = new DenseTernaryPolynomial(fInt);
}
// Initializes fp from t
IntegerPolynomial fp;
if (fastFp)
{
fp = new IntegerPolynomial(n);
fp.Coeffs[0] = 1;
}
else
{
fp = t.ToIntegerPolynomial().InvertF3();
}
return new NTRUPrivateKey(t, fp, n, q, sparse, fastFp, polyType);
}
catch (IOException ex)
{
throw new NTRUException("NTRUPrivateKey:From", ex.Message, ex);
}
}
/// <summary>
/// Constructs a new polynomial from three sparsely populated ternary polynomials
/// </summary>
///
/// <param name="F1">F1 polynomial</param>
/// <param name="F2">F2 polynomial</param>
/// <param name="F3">F3 polynomial</param>
public ProductFormPolynomial(SparseTernaryPolynomial F1, SparseTernaryPolynomial F2, SparseTernaryPolynomial F3)
{
this._f1 = F1;
this._f2 = F2;
this._f3 = F3;
}