A data encryption/decryption system is provided which maintains in encrypted form one or more critical data elements required by a software program. A user must obtain a license key in order to decrypt the critical data elements before the software program can use them. The data elements can be chosen such that their contents provide a control mechanism for the correct operation of the executable software program. The system allows for the inclusion of different data elements with or within a single version of the software program. The different data elements are encrypted for different license keys to allow for different license options and corresponding levels of control and flexibility in the delivery of the software program.