Systems and methods for transmitting critical data to a server are provided. The data structure intended for transmission to the server is divided up on the client side into a substructure containing critical data (CD) and a substructure not containing CD. The substructure containing CD is further divided up at the client side into at least two substructures and the resulting substructures are sent consecutively to the server via a node with a transformation module. The substructure not containing CD is sent directly to the server, bypassing the node with the transformation module. After receiving the substructures, they are combined at the server side into a single data structure. The critical data are data with respect to which the law of the state in whose jurisdiction the client or an authorized entity is located imposes restrictions on the gathering, storage, accessing, dissemination and processing thereof.