#include <server.h>

Public Member Functions
	Server (const PaillierPublicKey &paillierPublicKey, const DgkPublicKey &dgkPublicKey)
	Constructor. More...

	~Server ()
	Destructor - void implementation.

Paillier::Ciphertext	SecureComparison (const Paillier::Ciphertext &a, const Paillier::Ciphertext &b) const
	Computes the relation between the inputs. More...

void	SetClient (const std::shared_ptr< const Client > &client)
	Sets a reference to the Privacy Service Provider. More...

const std::shared_ptr < SecureComparisonServer > &	GetSecureComparisonServer () const
	Getter for this->secureComparisonServer. More...

Private Member Functions
	Server (Server const &)
	Copy constructor - not implemented.

Server	operator= (Server const &)
	Copy assignment operator - not implemented.

Private Attributes
std::weak_ptr< const Client >	client
	A reference to the Client.

Paillier	paillierCryptoProvider
	Paillier crypto provider.

Dgk	dgkCryptoProvider
	DGK crypto provider.

const std::shared_ptr < SecureComparisonServer >	secureComparisonServer
	A reference to the SecureComparisonServer.

Static Private Attributes
static const std::string	configurationPath
	Service Provider configuration path. More...

Detailed Description

Server.

Definition at line 51 of file secure_face_recognition/server.h.

Constructor & Destructor Documentation

SeComLib::SecureFaceRecognition::Server::Server	(	const PaillierPublicKey &	paillierPublicKey,
		const DgkPublicKey &	dgkPublicKey
	)

Constructor.

Parameters

paillierPublicKey	The Paillier public key
dgkPublicKey	The DGK public key

Definition at line 45 of file secure_face_recognition/server.cpp.

Member Function Documentation

const std::shared_ptr< SecureComparisonServer > & SeComLib::SecureFaceRecognition::Server::GetSecureComparisonServer ( ) const

Getter for this->secureComparisonServer.

Returns: The SecureComparisonServer instance.

Definition at line 80 of file secure_face_recognition/server.cpp.

Paillier::Ciphertext SeComLib::SecureFaceRecognition::Server::SecureComparison	(	const Paillier::Ciphertext &	a,
		const Paillier::Ciphertext &	b
	)		const

Computes the relation between the inputs.

Parameters

a	Paillier encryption
b	Paillier encryption

Returns: \( a < b ? [0] : [1] \)

To determine the minimum value, the server can compute \( [min] = [a + z_l (b - a)] = [a] ([y] \times ([b] [a]^{-1})) \) using an interactive protocol for the secure multiplication. Since this operation is rather expensive and the client already has the value \( d = 2^l + a - b + r \), the server can blind \( [y] \) with \( \eta \in_R \{0, 1\} \): if \( \eta = 1 \Rightarrow [\tilde{y}] = [1] [y]^{-1} \) else \( [\tilde{y}] = [y] \) and send it to the client. The client can decrypt \( [\tilde{y}] \) and compute \( [y d] \), which gets sent back to the server. The server now computes \( [\tilde{min}] = [b + y d - (r + 2^l) y] = [b] [yd] [y]^{-(r + 2^l)} \). If \( \eta = 1 \Rightarrow [min] = [\tilde{min}] \) else \( [min] = [a + b - \tilde{min}] = [a] [b] [\tilde{min}]^{-1} \)

Definition at line 56 of file secure_face_recognition/server.cpp.

void SeComLib::SecureFaceRecognition::Server::SetClient ( const std::shared_ptr< const Client > & client )

Sets a reference to the Privacy Service Provider.

Parameters

client a Client instance

Definition at line 72 of file secure_face_recognition/server.cpp.