private_recommendations_data_packing/secure_comparison_client.cpp

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/*
SeComLib
Copyright 2012-2013 TU Delft, Information Security & Privacy Lab (http://isplab.tudelft.nl/)

Contributors:
Inald Lagendijk (R.L.Lagendijk@TUDelft.nl)
Mihai Todor (todormihai@gmail.com)
Thijs Veugen (P.J.M.Veugen@tudelft.nl)
Zekeriya Erkin (z.erkin@tudelft.nl)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include "secure_comparison_client.h"
//avoid circular includes
#include "secure_comparison_server.h"

namespace SeComLib {
namespace PrivateRecommendationsDataPacking {
    SecureComparisonClient::SecureComparisonClient (const Paillier &paillierCryptoProvider, const Dgk &dgkCryptoProvider) :
        paillierCryptoProvider(paillierCryptoProvider),
        dgkCryptoProvider(dgkCryptoProvider),
        dgkComparisonClient(std::make_shared<DgkComparisonClient>(paillierCryptoProvider, dgkCryptoProvider)) {
    }

    void SecureComparisonClient::UnpackZ (const Paillier::Ciphertext &z, const std::deque<BigInteger> &emptyBuckets, const size_t encryptedBucketsCount) {
        BigInteger plaintextZ = this->paillierCryptoProvider.DecryptInteger(z);

        this->zi.clear();

        if (encryptedBucketsCount == emptyBuckets.size()) {
            for (size_t i = 0; i < emptyBuckets.size() - 1; ++i) {
                this->zi.emplace_back((plaintextZ % emptyBuckets[i + 1]) / emptyBuckets[i]);
            }
            this->zi.emplace_back(plaintextZ / emptyBuckets[emptyBuckets.size() - 1]);//emptyBuckets[i + 1] > plaintextZ
        }
        else {
            for (size_t i = 0; i < encryptedBucketsCount; ++i) {
                this->zi.emplace_back((plaintextZ % emptyBuckets[i + 1]) / emptyBuckets[i]);
            }
        }
    }

    void SecureComparisonClient::SetZi (const size_t i) const {
        this->dgkComparisonClient->SetZModTwoPowL(this->zi[i]);
    }

    void SecureComparisonClient::SetServer (const std::shared_ptr<SecureComparisonServer> &secureComparisonServer) {
        this->secureComparisonServer = secureComparisonServer;
        this->dgkComparisonClient->SetServer(secureComparisonServer->GetDgkComparisonServer());
    }

    const std::shared_ptr<DgkComparisonClient> &SecureComparisonClient::GetDgkComparisonClient () const {
        return this->dgkComparisonClient;
    }

    void SecureComparisonClient::DebugPaillierEncryption (const Paillier::Ciphertext &input) const {
        std::cout << this->paillierCryptoProvider.DecryptInteger(input).ToString(2) << std::endl;
    }

}//namespace PrivateRecommendationsDataPacking
}//namespace SeComLib