private async Task <BitArray> UnmaskOutputs(OutputPartyMapping outputMapping, BitArray localSharesOfOutput)
{
List <int>[] outputIds = new List <int> [MultiPartySession.NumberOfParties];
for (int partyId = 0; partyId < outputIds.Length; ++partyId)
{
outputIds[partyId] = new List <int>();
}
for (int outputId = 0; outputId < outputMapping.NumberOfOutputs; ++outputId)
{
for (int partyId = 0; partyId < MultiPartySession.NumberOfParties; ++partyId)
{
if (outputMapping.GetAssignedParties(outputId).Contains(partyId))
{
outputIds[partyId].Add(outputId);
}
}
}
foreach (ITwoPartyNetworkSession session in MultiPartySession.RemotePartySessions)
{
List <int> remoteOutputIds = outputIds[session.RemoteParty.Id];
if (remoteOutputIds.Count > 0)
{
BitArray localSharesOfRemoteOutput = new BitArray(remoteOutputIds.Count);
for (int i = 0; i < remoteOutputIds.Count; ++i)
{
localSharesOfRemoteOutput[i] = localSharesOfOutput[remoteOutputIds[i]];
}
await session.Channel.WriteMessageAsync(localSharesOfRemoteOutput.ToBytes());
}
}
List <int> localOutputIds = outputIds[MultiPartySession.LocalParty.Id];
BitArray localOutputValues = new BitArray(localOutputIds.Count);
for (int i = 0; i < localOutputIds.Count; ++i)
{
localOutputValues[i] = localSharesOfOutput[localOutputIds[i]];
}
if (localOutputIds.Count > 0)
{
foreach (ITwoPartyNetworkSession session in MultiPartySession.RemotePartySessions)
{
BitArray remoteSharesOfLocalOutput = BitArray.FromBytes(await session.Channel.ReadMessageAsync(), localOutputIds.Count);
localOutputValues.Xor(remoteSharesOfLocalOutput);
}
}
return(localOutputValues);
}
public async Task <BitArray> EvaluateAsync(IBatchEvaluableCircuit evaluable, InputPartyMapping inputMapping, OutputPartyMapping outputMapping, BitArray localInputValues)
{
if (inputMapping.NumberOfInputs != evaluable.Context.NumberOfInputGates)
{
throw new ArgumentException(
"The number of inputs in input mapping does not match the number of declared inputs in the circuit.",
nameof(inputMapping)
);
}
if (outputMapping.NumberOfOutputs != evaluable.Context.NumberOfOutputGates)
{
throw new ArgumentException(
"The number of outputs in output mapping does not match the number of declared outputs in the circuit.",
nameof(outputMapping)
);
}
SecretSharingBooleanCircuitEvaluator evaluator = new SecretSharingBooleanCircuitEvaluator(MultiPartySession, _multiplicativeSharing);
BitArray maskedInputs = await MaskInputs(inputMapping, localInputValues);
Task <Bit>[] inputTasks = maskedInputs.Select(Task.FromResult).ToArray();
Task <Bit>[] outputTasks = evaluable.Evaluate(evaluator, inputTasks);
BitArray maskedOutputs = new BitArray(await Task.WhenAll(outputTasks));
return(await UnmaskOutputs(outputMapping, maskedOutputs));
}
