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SeComLib
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SeComLib
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Service Provider. More...
#include <service_provider.h>
Public Types | |
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typedef std::deque < Paillier::Ciphertext > | EncryptedUserData |
| Encrypted user data. | |
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typedef std::deque < EncryptedUserData > | EncryptedUserDataContainer |
| Container for encrypted user data. | |
Public Member Functions | |
| ServiceProvider (const PaillierPublicKey &paillierPublicKey, const DgkPublicKey &dgkPublicKey) | |
| Constructor. More... | |
| ~ServiceProvider () | |
| Destructor - void implementation. | |
| void | GenerateDummyDatabase () |
| Generates a dummy database for the users. More... | |
| void | ComputeSimilarityValues () |
| Computes the similarity values between each pair of users for the first \( R \) items. More... | |
| void | ComputeUserRecommendations () |
| Computes \( [\Gamma] \), \( [L] \) and \( [UR_{sum}] \) for each user. More... | |
| const Paillier::Ciphertext & | GetEncryptedL (size_t userId) const |
| Returns the \( [L] \) value for the specified user. More... | |
| const EncryptedUserData & | GetEncryptedURSum (size_t userId) const |
| Returns the \( [UR_{sum}] \) vector for the specified user. More... | |
| void | SetPrivacyServiceProvider (const std::shared_ptr< const PrivacyServiceProvider > &privacyServiceProvider) |
| Sets a reference to the Privacy Service Provider. More... | |
| const std::shared_ptr < SecureComparisonServer > & | GetSecureComparisonServer () const |
| Getter for this->secureComparisonServer. More... | |
| const std::shared_ptr < SecureMultiplicationServer < Paillier > > & | GetSecureMultiplicationServer () const |
| Getter for this->secureMultiplicationServer. More... | |
Private Member Functions | |
| ServiceProvider (ServiceProvider const &) | |
| Copy constructor - not implemented. | |
| ServiceProvider | operator= (ServiceProvider const &) |
| Copy assignment operator - not implemented. | |
Private Attributes | |
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std::weak_ptr< const PrivacyServiceProvider > | privacyServiceProvider |
| A reference to the PrivacyServiceProvider. | |
| Paillier | paillierCryptoProvider |
| Paillier crypto provider. | |
| Dgk | dgkCryptoProvider |
| DGK crypto provider. | |
| size_t | userCount |
| Number of users who need recommendations. | |
| size_t | itemCount |
| Number of ratings per user. | |
| size_t | denselyRatedItemCount |
| Number of densely rated items. | |
| size_t | ratingBitSize |
| The size of the user ratings (in bits) | |
| unsigned int | digitsToPreserve |
| Number of digits preserved from the normalized user ratings. | |
| BigInteger | similarityTreshold |
| \( s^2 \delta \) - Scaled public threshold value for the similarity values | |
| std::string | ratingsFilePath |
| The path to the file containing precomputed ratings. | |
| EncryptedUserDataContainer | normalizedScaledRatings |
| \( [\tilde{V}_i^d] \) | |
| EncryptedUserDataContainer | sparseRatings |
| \( [V_i^p] \) | |
| EncryptedUserData | gammaValues |
| \( [\Gamma] \) | |
| EncryptedUserData | LValues |
| Vector of \( [L] \) values, where L is the number of users similar to a given user. | |
| EncryptedUserDataContainer | URSumContainer |
| Contains the \( [UR_{sum}] \) vectors for each user. | |
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const std::shared_ptr < SecureComparisonServer > | secureComparisonServer |
| A reference to the SecureComparisonServer. | |
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std::shared_ptr < SecureMultiplicationServer < Paillier > > | secureMultiplicationServer |
| A reference to the SecureMultiplicationServer. | |
Static Private Attributes | |
| static const std::string | configurationPath |
| Service Provider configuration path. More... | |
Service Provider.
Definition at line 67 of file service_provider.h.
| SeComLib::PrivateRecommendations::ServiceProvider::ServiceProvider | ( | const PaillierPublicKey & | paillierPublicKey, |
| const DgkPublicKey & | dgkPublicKey | ||
| ) |
Constructor.
\( \delta \) needs to be scaled with \( s^2 \), because \( sim_{(A, B)} \) is the dot product of two scaled vectors
| paillierPublicKey | The Paillier public key |
| dgkPublicKey | The DGK public key |
Definition at line 47 of file service_provider.cpp.
| void SeComLib::PrivateRecommendations::ServiceProvider::ComputeSimilarityValues | ( | ) |
Computes the similarity values between each pair of users for the first \( R \) items.
Computes \( [sim_{(A, B)}] = \prod_{r = 0}^{R-1}{[\tilde{v}_{(A, r)}^d \tilde{v}_{(B, r)}^d]} = \prod_{r = 0}^{R-1}{([\tilde{v}_{(A, r)}^d] \otimes [\tilde{v}_{(B, r)}^d])} \), where \( A < B \), because \( [sim_{(A, B)}] = [sim_{(B, A)}] \)
Computes the \( [\Gamma] \) vector for each user, where \( [\Gamma_A] = ([\gamma_{(A, 0)}], [\gamma_{(A, 1)}], ..., [\gamma_{(A, N - 2)}])^T \), where \( [\gamma_{(A, i)}] = sim_{(A, i)} >= \delta ? [1] : [0] \)
Definition at line 154 of file service_provider.cpp.
| void SeComLib::PrivateRecommendations::ServiceProvider::ComputeUserRecommendations | ( | ) |
Computes \( [\Gamma] \), \( [L] \) and \( [UR_{sum}] \) for each user.
Computes \( [L] \) and \( [UR_{sum}] \) for each user
\( [L] = \left[ \displaystyle\sum_{i = 0}^{N - 2}{\gamma_{(A, i)}} \right] = \displaystyle\prod_{i=0}^{N - 2}{[\gamma_{(A, i)}]} \)
\( [UR_i] := ([\gamma_{(A, i)}] \otimes [v_{(i, 0)}^p], ..., [\gamma_{(A, i)}] \otimes [v_{(i, M - R - 1)}^p])^T = ([\gamma_{(A, i)} v_{(i, 0)}^p], ..., [\gamma_{(A, i)} v_{(i, M - R - 1)}^p])^T = ([UR_{(i, 0)}], ..., [UR_{(i, M - R - 1)}])^T \)
where \( [UR_i] = \left\{ \begin{array}{lc} [V_{(i, j)}^p], & if \; \gamma_{(A, i)} \; is \; 1 \\ ([0], ..., [0])^T, & if \; \gamma_{(A, i)} \; is \; 0 \end{array} \right. \)
\( [UR_{user}^{sum}] = \left( \displaystyle\prod_{i = 0}^{N - 2}{[UR_{(i, 0)}]}, ..., \displaystyle\prod_{i = 0}^{N - 2}{[UR_{(i, M - R - 1)}]} \right)^T = \left( \left[ \displaystyle\sum_{i = 0}^{N - 2}{UR_{(i, 0)}} \right], ..., \left[\displaystyle\sum_{i = 0}^{N - 2}{UR_{(i, M - R - 1)}}\right] \right)^T \)
Initialize L with the first gamma value (note that \( \gamma_{(A, B)} = \gamma_{(B, A)} \))
Compute \( \left( [UR_{(0, 0)}], ..., [UR_{(0, M - R - 1)}] \right) \)
Compute the rest: \( \left( \displaystyle\prod_{i = 1}^{N - 2}{[UR_{(i, 0)}]}, ..., \displaystyle\prod_{i = 1}^{N - 2}{[UR_{(i, M - R - 1)}]} \right) \)
Compute the gammaValues vector index from the matrix indices
Compute \( \displaystyle\prod_{i = 0}^{N - 2}{[UR_{(i, j)}]} \)
Definition at line 210 of file service_provider.cpp.
| void SeComLib::PrivateRecommendations::ServiceProvider::GenerateDummyDatabase | ( | ) |
Generates a dummy database for the users.
Generates \( M \) item ratings for each of the \( N \) users and scales them.
Encrypts the scaled normalized densely related ratings: \( [\tilde{V}_i^d] = ([\tilde{v}_{(i, 0)}^d], ..., [\tilde{v}_{(i, R - 1)}^d])^T \) and the sparse ratings for the rest of the items: \( [V_i^p] = ([v_{(i, 0)}^p], ..., [v_{(i, M - R - 1)}^p])^T \).
| std::runtime_error | the ratings file can't be opened |
Load ratings from file
Definition at line 70 of file service_provider.cpp.
| const Paillier::Ciphertext & SeComLib::PrivateRecommendations::ServiceProvider::GetEncryptedL | ( | size_t | userId | ) | const |
Returns the \( [L] \) value for the specified user.
| userId | The index of the user |
Definition at line 270 of file service_provider.cpp.
| const ServiceProvider::EncryptedUserData & SeComLib::PrivateRecommendations::ServiceProvider::GetEncryptedURSum | ( | size_t | userId | ) | const |
Returns the \( [UR_{sum}] \) vector for the specified user.
| userId | The index of the user |
Definition at line 278 of file service_provider.cpp.
| const std::shared_ptr< SecureComparisonServer > & SeComLib::PrivateRecommendations::ServiceProvider::GetSecureComparisonServer | ( | ) | const |
Getter for this->secureComparisonServer.
Definition at line 294 of file service_provider.cpp.
| const std::shared_ptr< SecureMultiplicationServer< Paillier > > & SeComLib::PrivateRecommendations::ServiceProvider::GetSecureMultiplicationServer | ( | ) | const |
Getter for this->secureMultiplicationServer.
Definition at line 301 of file service_provider.cpp.
| void SeComLib::PrivateRecommendations::ServiceProvider::SetPrivacyServiceProvider | ( | const std::shared_ptr< const PrivacyServiceProvider > & | privacyServiceProvider | ) |
Sets a reference to the Privacy Service Provider.
| privacyServiceProvider | a PrivacyServiceProvider instance |
Definition at line 285 of file service_provider.cpp.
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staticprivate |
Service Provider configuration path.
Set the configuration path.
Definition at line 158 of file service_provider.h.
1.8.6
