The subject matter discloses a computerized system, comprising a computerized device communicating with a third party server, that comprises a memory unit that stores a representation of a Boolean circuit and a processing unit for calculating a result of the Boolean circuit according to a string used as input for the Boolean circuit and calculating a first predefined function on the result of the Boolean circuit. The system also comprises a first auxiliary server communicating with the computerized device, the first auxiliary server comprises a processing unit for calculating a second predefined function on the result of the Boolean circuit received from the computerized device and a second auxiliary server communicating with the computerized device comprises a processing unit for comparing the result of the first predefined function and the result of the second predefined function.