/// <summary>
/// Given an encrypted BallotContest, validates the encryption state against
/// a specific encryption seed and public key
/// by verifying the accumulated sum of selections match the proof.
/// Calling this function expects that the object is in a well-formed encrypted state
/// with the `ballot_selections` populated with valid encrypted ballot selections,
/// the ElementModQ `description_hash`, the ElementModQ `crypto_hash`,
/// and the ConstantChaumPedersenProof all populated.
/// Specifically, the seed hash in this context is the hash of the ContestDescription,
/// or whatever `ElementModQ` was used to populate the `description_hash` field.
/// </summary>
public unsafe bool IsValidEncryption(
ElementModQ encryptionSeed,
ElementModP elGamalPublicKey,
ElementModQ cryptoExtendedBaseHash)
{
return(NativeInterface.CiphertextBallotContest.IsValidEncryption(
Handle, encryptionSeed.Handle, elGamalPublicKey.Handle,
cryptoExtendedBaseHash.Handle));
}
public unsafe CiphertextElectionContext(ulong numberOfGuardians,
ulong quorum,
ElementModP publicKey,
ElementModQ commitmentHash,
ElementModQ manifestHash)
{
var status = NativeInterface.CiphertextElectionContext.Make(
numberOfGuardians, quorum, publicKey.Handle, commitmentHash.Handle, manifestHash.Handle, out Handle);
if (status != Status.ELECTIONGUARD_STATUS_SUCCESS)
{
Console.WriteLine($"CiphertextElectionContext Error Status: {status}");
}
}
/// <summary>
/// Encrypts a message with a given random nonce and an ElGamal public key.
///
/// <param name="plaintext"> Message to elgamal_encrypt; must be an integer in [0,Q). </param>
/// <param name="nonce"> Randomly chosen nonce in [1,Q). </param>
/// <param name="publicKey"> ElGamal public key. </param>
/// <returns>A ciphertext tuple.</returns>
/// </summary>
unsafe public static ElGamalCiphertext Encrypt(
ulong plaintext, ElementModQ nonce, ElementModP publicKey)
{
var status = NativeInterface.ElGamal.Encrypt(
plaintext, nonce.Handle, publicKey.Handle,
out NativeElGamalCiphertext ciphertext);
if (status != Status.ELECTIONGUARD_STATUS_SUCCESS)
{
Console.WriteLine($"Encrypt Error Status: {status}");
return(null);
}
return(new ElGamalCiphertext(ciphertext));
}
protected override bool Free()
{
if (IsClosed)
{
return(true);
}
var status = ElementModP.Free(this);
if (status != Status.ELECTIONGUARD_STATUS_SUCCESS)
{
Console.WriteLine($"ElementModP Error Free: {status}");
return(false);
}
return(true);
}
