Privacy Preservation for Friend-Recommendation Applications

Algorithm 1

Encryption.

Input:

: all the attributes groups( );

: the attributes group;

: personal information ( );

: personal information version;

: the key of attributes group;

: the key of attributes group;

: the key of attributes group;

: the number of attributes groups;

Output:

: all the encrypted attributes (

);

: all the encrypted personal information (

);

fordo

;

if then

;

;

end

end

return , ;