public ElGamalAbstractCipher(ElGamalKeyStruct p_key_struct)
{
o_key_struct = p_key_struct;
o_plaintext_blocksize = p_key_struct.getPlaintextBlocksize();
o_ciphertext_blocksize = p_key_struct.getCiphertextBlocksize();
o_block_size = o_plaintext_blocksize;
}
public ElGamalAbstractCipher(ElGamalKeyStruct p_key_struct)
{
// set the key details
o_key_struct = p_key_struct;
// calculate the blocksizes
o_plaintext_blocksize = p_key_struct.getPlaintextBlocksize();
o_ciphertext_blocksize = p_key_struct.getCiphertextBlocksize();
// set the default block for plaintext, which is suitable for encryption
o_block_size = o_plaintext_blocksize;
}
public override byte[] Multiply(byte[] p_first, byte[] p_second)
{
var blocksize = o_key_struct.getCiphertextBlocksize();
if (p_first.Length != blocksize)
{
throw new ArgumentException("p_first", "Ciphertext to multiply should be exactly one block long.");
}
if (p_second.Length != blocksize)
{
throw new ArgumentException("p_second", "Ciphertext to multiply should be exactly one block long.");
}
return(Homomorphism.ElGamalHomomorphism.Multiply(p_first, p_second, o_key_struct.P.getBytes()));
}
