1. Software Watermarking Deterring Software Piracy
Beaux Sharifi
CS591
Fall 2005

2. CS591 Software Watermarking - Beaux Sharifi
Problem of Piracy
35% of all PC software pirated in 2004
$33 Billion dollars in losses in 2004
Software piracy is expected to rise due to increase in Internet usage
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

3. What is Software Watermarking?
Software Watermarking is the technique of embedding a secret message (digital rights) into a cover message (program).
A form of Steganography
Does not prevent piracy. Rather, deters it.
(P+W) W
Key P
(P+W)
(P+W)
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
(P+W)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

4. Software Watermarking Types
Static Software Watermarks:
Embedded within the static structure of the program.
Static Data Watermarks
Static Code Watermarks
Dynamic Software Watermarks
Embedded within the execution state of the program.
Easter Eggs
Execution Trace
Dynamic Data Structure
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

5. Example Static Watermark
Static Data Watermark:
char copyright[] = “Property of XYZ Corporation, 2004”;
Can Extract using GNU Strings:
$> strings program.exe | grep XYZ
$> Property of XYZ Corporation, 2004
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

6. Example Dynamic Watermark
Dynamic Easter Egg
Watermark:
Start Microsoft FreeCell
Press Ctrl+Shift+F10
Click Abort
Double-click Cards
You Win!
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

7. De-watermarking Attacks
Several types:
Distortive: Destroy the watermark
Subtractive: Remove the watermark
Additive: Add additional watermarks
Collusive: Compare the watermark
Statistical: Analyze the watermark
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

8. CS591 Software Watermarking - Beaux Sharifi
Example Attack
Distortive Attack:
char copyright[] = “Property of XYZ Corporation, 2004”;
char a[] = “Prop”;
char b[] = “erty”;
char c[] = “ of “;
char d[] = “XY”;
char e[] = “Z”; …
char m[] = “04”;
char copyright[MAX];
copyright = a + b + … + m;
Can no longer extract using GNU Strings:
$> strings program.exe | grep XYZ
$>
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

9. CS591 Software Watermarking - Beaux Sharifi
Desirable Properties
Desirable Properties of Watermarks:
Resilient to Attacks
Stealthy
Efficient
Have a High Data Rate
Easy to Embed & Retrieve
Mathematically Deliberate
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

10. Limitations of Software Watermarks
Problem: All traditional software watermarking techniques except easter eggs are susceptible to distortive attacks.
WSN’s have a variety of applications
Golden Gate has motes used to study the effect of wind, traffic, and earthquakes on the structure of the bridge (use accelerometers on a small section)
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

11. Dynamic Graph Watermarking
A new type of Dynamic Data Structure Watermark.
Embeds watermark in the topology of a dynamically build graph structure.
Result: Watermark embedded within pointer semantics of program. Therefore, it is resilient to distortive semantic-preserving attacks!
P + W
if (input == I) {
P = new Node();
Q = new Node();
addEdge(P, Q); … } P
P = new Node();
Q = new Node();
addEdge(P, Q); …
Prime
Number Q
I also chose to study positioning algorithms based on sheer curiosity.
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

12. CS591 Software Watermarking - Beaux Sharifi
Attacks on DGW
Dynamic Graph Watermarking (DGW) is still vulnerable to advanced types of distortive attacks.
Can make DGW stronger by:
Adding tamperproofing:
Integrity Checking
Check the integrity of DGW structure periodically.
Constant Encoding
Substitute program constants with DGW sub-tree.
Opaque Predicates
Create false dependencies on DGW structure
Adding obfuscation:
Obfuscate each copy of DGW program to protect against collusive attacks.
Combining multiple approaches achieves the best results!
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

13. CS591 Software Watermarking - Beaux Sharifi
Future Work
No software watermarking technique is immune to all types of attacks.
There are no known defenses against Additive Attacks.
11/24/2018
CS591 Software Watermarking - Beaux Sharifi

14. CS591 Software Watermarking - Beaux Sharifi
References
Business Software Alliance, “Sixth Annual BSA global software piracy study”, undated, (Accessed: 7 Dec, 2005)
C. Collberg and C. Thomborson, “Software Watermarking: Models and Dynamic Embeddings”, presented at POPL ’99. 26th ACM SIGPLAN-SIGACT. Symposium on Principles of Programming Languages. ACM, New York, NY, USA, 1999.
Y. He, “Tamperproofing a Software Watermark by Encoding Constants”, Masters Thesis, University of Auckland, 2002.
J. Palsberg, S. Krishnaswamy, K. Minseok, D. Ma, S. Qiuyun, and Y. Zhang, “Experience with Software Watermarking”, presented at 16th Annual Computer Security Applications Conference (ACSAC’00). IEEE Comput. Soc., Los Alamitos, CA, USA, 2000
11/24/2018
CS591 Software Watermarking - Beaux Sharifi