General Protection Guidelines

The following guidelines should be followed, regardless of the software protection strategies being implemented.

Thales thoroughly and constantly investigates potential and actual threats to software security, and Sentinel LDK is continuously being updated to counter such threats—before they can compromise the security of your software.

Use the Most Up-To-Date Protection Software

Protection software updates generally include enhancements to counter the most recent threats. Always check for and use the most recent version of Sentinel LDK protection software that is available. The latest software can be downloaded from the Sentinel Web site.

Constantly Re-Evaluate Protection Strategies

Frequently consider what protection strategies you can upgrade or enhance to provide stronger security for your software.

Use Evolving Strategies to Prevent Predictability

Vary the strategies that you implement between your software releases. If a software cracker is able to detect a pattern to your protection strategies, the strategies can more easily be negated or evaded.

Vary Behavior When a Cracking Attempt Is Detected

When a cracking attempt is detected (for example, through using a checksum—described later in the section), delay the reactive behavior of your software, thus breaking the logical connection between “cause” and “effect.” Delayed reaction confuses a software cracker by obscuring the link between the cracking attempt and the negative reaction of the software to that attempt.

Behavior such as impairing program functionality when a cracking attempt is detected can be very effective. Additional behaviors could include causing the program to crash, overwriting data files, or deliberately causing the program to become inaccurate, causing the program to become undependable.