private_recommendations_utils/secure_comparison_server.h

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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.
*/
#ifndef SECURE_COMPARISON_SERVER_HEADER_GUARD
#define SECURE_COMPARISON_SERVER_HEADER_GUARD

//include our headers
#include "utils/config.h"
#include "core/big_integer.h"
#include "core/random_provider.h"
#include "core/paillier.h"
#include "core/dgk.h"
#include "core/randomizer_cache.h"

#include "comparison_blinding_factor_cache_parameters.h"
#include "comparison_blinding_factor_container.h"
#include "dgk_comparison_server.h"

namespace SeComLib {
using namespace Core;

namespace PrivateRecommendationsUtils {
    //forward-declare required classes
    class SecureComparisonClient;

    class SecureComparisonServer {
    public:
        SecureComparisonServer (const Paillier &paillierCryptoProvider, const Dgk &dgkCryptoProvider, const std::string &configurationPath);

        SecureComparisonServer (const Paillier &paillierCryptoProvider, const Dgk &dgkCryptoProvider, const BigInteger &similarityTreshold, const std::string &configurationPath);

        ~SecureComparisonServer () {}

        Paillier::Ciphertext Compare (const Paillier::Ciphertext &a, const Paillier::Ciphertext &b);

        Paillier::Ciphertext Compare (const Paillier::Ciphertext &similarityValue);

        void SetClient (const std::shared_ptr<SecureComparisonClient> & secureComparisonClient);

        const std::shared_ptr<DgkComparisonServer> &GetDgkComparisonServer () const;

    private:
        typedef ComparisonBlindingFactorContainer<Paillier, ComparisonBlindingFactorCacheParameters> BlindingFactorContainer;

        const Paillier &paillierCryptoProvider;

        const Dgk &dgkCryptoProvider;

        size_t l;

        Paillier::Ciphertext minusThreshold;

        BigInteger twoPowL;

        Paillier::Ciphertext encryptedTwoPowL;

        RandomizerCache<BlindingFactorContainer> blindingFactorCache;

        const std::shared_ptr<DgkComparisonServer> dgkComparisonServer;

        std::weak_ptr<const SecureComparisonClient> secureComparisonClient;

        Paillier::Ciphertext compare (const Paillier::Ciphertext &a, const Paillier::Ciphertext &minusB);

        SecureComparisonServer (SecureComparisonServer const &);

        SecureComparisonServer operator= (SecureComparisonServer const &);
    };
}//namespace PrivateRecommendationsUtils
}//namespace SeComLib

#endif//SERVICE_PROVIDER_HEADER_GUARD