Abstract: A system for electronically transmitting data objects such as computer programs with a means for verifying that the computer program was actually received and the terms and conditions of its use accepted by the receiver is presented. In this system, the computer program itself controls the verification for its receipt and acceptance. The sender first modifies the program to be delivered, rendering it non-executable in the form in which it will be received by the user initially. The sender inserts into the program an enabling routine and a verification indicia. The enabling routine is capable of rendering the non-executable program into an executable state if certain prerequisite conditions, contained in the verification and enabling routine, are met.