Software Protection Techniques
- 1. Presented by Seminar Guide Chaitanya Anpat Prof. Pritesh Patil TE – IT Monday, October 24, 20161 Copy Protection
- 2. Agenda • Introduction • Brief idea about protection methods • Code confusion • Debuggers • Code confusion techniques • conclusion
- 3. Introduction • Copy protection is effort to prevent cracking • Cracking-modification to binary files to remove protection reverse engineering • Discovering technical principles of device,object,system,software. • It often involves disassembling exe code to get machine code and bypass software security.
- 4. Piracy Game Music S/w • This increases piracy. • Loss due to piracy is about $60 billion
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- 6. Method of protection • hardware based • Hardware device is integrated with software and used to protect and license an application. • It uses device called USB hardware • Software executes only if devise is actually present on machine • E.g.-ANSYS(related to ME)
- 7. • Serial key generation • enter serial key • Serial key compare • If match installation complete
- 8. Encryptions • Encoding applications in such a way that only authorized users can use it • It doesn’t prevent hacking • Used to prevent data at rest like files and data at transits like data transfer via networks
- 9. Debug-Blocker • In Armadillo, we find another feature called Debug- Blocker. • Armadillo creates 2 processes, referred to them as father ( or parent ) and child. The father process acts as a debugger, trying to protect the child from other debuggers.
- 10. Code confusion/obfuscation • Process of confusing • Transforms source code such that it is difficult for human to grasp and debugger to disassemble accurately • confused code should be functionally equivalent to users perspective. • introduce code confusing techniques so as make code difficult to debug and which prevent s/w to be reversed.
- 11. Debugger • Linear sweep - win debugger • Control flow not followed • Recursive traversal –Ollydebuger • control flow followed
- 12. Inline assembly `c` code for Hello with data byte inserted _asm { jmp L1 ; logic to “skip” data byte _emit 0x00 ; inserted data byte } L1:printf("Hello, World!!!n"); }
- 14. Code confusion technique Layout Data Control Preventive Technique
- 15. Layout technique • Layout obfuscations modify the layout structure of the program by two basic methods: renaming identifiers and removing debugging information • They make the program code less informative to a reverse engineer.
- 16. Before void my_output() { int count; for (count = 0; count<=4; ++count) printf("Hello %d!n", count); }
- 17. • Tools used this technique are SD Obfuscator CXX obfuscator. • They will automatically output confused code whose functionality remains same after obfuscation.
- 18. After #define a int #define b printf #define c for a l47() { a l118; c(l118=0;l118<0x664+196-0x71e;++l118) b("x48x65x6cx6cx6fx20x25x64x21n",l118); }
- 19. Data code confusion technique • It changes the program’s use of data or data structures. • The storage of data can be obfuscated by replacing current data definitions with those which do not make sense for their intended use. For example, a loop iteration variable can be replaced with another variable type besides an integer.
- 21. Control flow code confusion • It changes the flow of the program executing code in parallel • insert new functions • mislead the disassembler while executing concurrently
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