Native Delphi Protection Utility (NDPU) is a new kind of protection tool for Delphi applications.

The main advantages of NDPU are:
(1) protection of not code, but data needed to run the application;
(2) use of only native (but peculiar) to Delphi means;
(3) no external processing (such as packing or encryption) of Delphi-produced executable;
(4) source code is temporarily modified, then after re-compiling the application is protected;
(5) the protected executable is natively compiled by Delphi (no compatibility problems therefore);
(6) the key is not checked but is used to restore the protected functionality;
(7) without correct key events are empty (the application may be launched, but it will not work);
(8) use of proprietary (not based on RTTI) technique of events initialization;
(9) strong (AES 128 bits) encryption;
(10) each key contains personal data, therefore each one may be easily identified.

The main function of NDPU is to produce trial versions with limited functionality of Delphi applications, though other protection kinds are also supported.
NDPU uses its own approach to the problem of protection of Delphi applications. It protects not code, but data needed to run the application. NDPU does not use a call of some checking routine to control execution of the protected application. Instead NDPU modifies the source code in such a manner that after re-compiling events of various components of the main form are empty. To work properly the protected application needs to restore these events.
The restoration, in turn, requires the key (without correct key "NDPUed" application has empty events). The protected application does not check the key for validity, but uses it to assign proper event handlers to the corresponding events. Needed to the assignment information is stored in the encrypted form in the binary resource. During this assignment NDPU uses proprietary (not based on RTTI) method of events initialization.
Use of strong encryption ensures that without correct key the protected application is very hard to be cracked (if possible at all) because part of the information needed to run the application properly exists inside .EXE file only in the encrypted form.
Without correct key the protected application will not respond to various events - that is it will not perform any programmed in the corresponding event handlers actions. The application may be launched, but it will not work.
Personal data contained in each key allows to easily identify each produced key.

More information about NDPU may be found at http://www.posolsoft.com/NDPU