service_provider.h

Go to the documentation of this file.

/*
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 SERVICE_PROVIDER_HEADER_GUARD
#define SERVICE_PROVIDER_HEADER_GUARD

//include our headers
#include "utils/config.h"
#include "utils/date_time.h"
#include "utils/cpu_timer.h"
#include "core/big_integer.h"
#include "core/random_provider.h"
#include "core/paillier.h"
#include "core/dgk.h"
#include "core/secure_multiplication_server.h"

#include "private_recommendations_utils/secure_comparison_server.h"


//include C++ libraries
#include <fstream>
#include <string>
#include <sstream>
#include <deque>
#include <stdexcept>

namespace SeComLib {

using namespace Core;
using namespace PrivateRecommendationsUtils;

//hackish way of computing everything for only a single user (see also client.h)
#define FIRST_USER_ONLY

namespace PrivateRecommendations {
    //forward-declare required classes
    class PrivacyServiceProvider;

    class ServiceProvider {
    public:
        typedef std::deque<Paillier::Ciphertext> EncryptedUserData;

        typedef std::deque<EncryptedUserData> EncryptedUserDataContainer;

        ServiceProvider (const PaillierPublicKey &paillierPublicKey, const DgkPublicKey &dgkPublicKey);

        ~ServiceProvider () {}

        void GenerateDummyDatabase ();

        void ComputeSimilarityValues ();

        void ComputeUserRecommendations ();

        const Paillier::Ciphertext &GetEncryptedL (size_t userId) const;

        const EncryptedUserData &GetEncryptedURSum (size_t userId) const;

        void SetPrivacyServiceProvider (const std::shared_ptr<const PrivacyServiceProvider> &privacyServiceProvider);

        const std::shared_ptr<SecureComparisonServer> &GetSecureComparisonServer () const;

        const std::shared_ptr<SecureMultiplicationServer<Paillier>> &GetSecureMultiplicationServer () const;

    private:
        std::weak_ptr<const PrivacyServiceProvider> privacyServiceProvider;

        Paillier paillierCryptoProvider;

        Dgk dgkCryptoProvider;

        size_t userCount;

        size_t itemCount;

        size_t denselyRatedItemCount;

        size_t ratingBitSize;

        unsigned int digitsToPreserve;

        BigInteger similarityTreshold;

        std::string ratingsFilePath;

        EncryptedUserDataContainer normalizedScaledRatings;

        EncryptedUserDataContainer sparseRatings;

        EncryptedUserData gammaValues;

        EncryptedUserData LValues;

        EncryptedUserDataContainer URSumContainer;

        const std::shared_ptr<SecureComparisonServer> secureComparisonServer;

        std::shared_ptr<SecureMultiplicationServer<Paillier>> secureMultiplicationServer;

        static const std::string configurationPath;

        ServiceProvider (ServiceProvider const &);

        ServiceProvider operator= (ServiceProvider const &);
    };
}//namespace PrivateRecommendations
}//namespace SeComLib

#endif//SERVICE_PROVIDER_HEADER_GUARD