1. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 1 Semantic Data Integrity DARPA Program Review Cornell Business & Technology Park 33 Thornwood Drive, Suite 500 Ithaca, NY 14850-1250 (607) 257-1975 David Rosenthal February 22, 2000

2. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 2 Team Members ORA WetStone Jiri Fridrich (consultant to WetStone)

3. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 3 Technical Objectives Support intrusion tolerance by developing improved data integrity methods to recover attacked data –Many factor influence effectiveness: Many different types of threats Different types and characteristics of data Variety of integrity mechanisms Different size and performance constraints –Want policy-based selection of mechanisms to effectively protect, recover, and reconstruct data that may be accidentally or maliciously damaged

4. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 4 Existing practice Current Methods – Protection of entire object One-way hash, Message authentication codes (MAC), Digital signatures –Replication –Access control and process control –Watermarking and self-embedding techniques Need better methods to facilitate partial recovery and to focus limited resources where they are needed most

5. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 5 Technical Approach Our research is directed in the following areas –Techniques for identifying and protecting data subsets –Developing new watermarking/self-embedding techniques –Exploring how to recover data subsets using secondary data (DSI Marks) and how to partially reconstruct the whole data object –How to select data protection and recovery mechanisms to meet integrity policy objectives Developing software to test the effectiveness of approach

6. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 6 Technical Approach Software

7. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 7 Added CarsDetected Forgery Forged ImageDetected Forgery SDI Workshop Examples

8. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 8 SDI Workshop Examples Original ImageSegmented Image

9. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 9 SDI Workshop Examples Forged ImageDetected Forgery Added Helicopters Detected Forgery

10. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 10 Forged ImageDetected Forgery Removed Helicopter Detected Forgery SDI Workshop Examples

11. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 11 Technical Approach Subsets Develop methods for forming subsets of an object, taking into account data characteristics and intended usage –Simple example Save signatures of a subset of a picture consisting of just the higher order bits of pixels If some lower order bits are changed, the signature on the subset will still check, and the picture can be partially reconstructed –Apply extra protection for key parts of an object

12. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 12 Technical Approach Subsets (cont.) We believe that a good selection of data subset formation methods can lead to improved –performance characteristics –likelihood that partially reconstructed objects will contain correct information about “interesting parts”

13. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 13 Technical Approach Hierarchical Subsets We have been experimenting with algorithms for automatically subsetting images based on uniformity criteria (combination of color, intensity, texture similarity) Split image into quadrants, test quadrants for uniformity; if a quadrant is uniform, do not subdivide it further. Otherwise, continue subdividing Then, merge all “adjacent” segments that share the same uniformity characteristics (or possibly some other desirable characteristics such as a common edge)

14. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 14 Technical Approach Hierarchical Subsets (cont.) Impose different integrity mechanisms at different layers of the decomposition, to achieve policy goals more efficiently

15. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 15 Technical Approach Secure Fragile Authentication Watermark Investigated some attacks that affect several proposed fragile watermark schemes Developed a secure fragile watermark that is resistant to these attacks –Uses secret key and the watermark is difficult to forge –Resistant to collage attack

16. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 16 Technical Approach Hybrid Watermark Have implemented a hybrid watermark –Distinguishes between image processing operations (filtering, lossy compression) and feature alteration/removal/replacement –Embed a semi-local (64 x 64) robust watermark that degrades gradually with alteration –Embed a local (8x8) fragile watermark on top that breaks with any alterations

17. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 17 Technical Approach Policy Policy will define the methods to apply to specific objects based on factors, such as: –Importance of the data or sub-data –Threats that need to be countered –Recovery time constraints –Resource limitations –Detectability of integrity measure –Integrity functionality that is available –Current situation (INFOCON, THREATCON)

18. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 18 Technical Approach Demonstration Environment We are developing an environment for demonstrating and testing our technology Current features include: –Split-and-merge with parameters –Policy-based integrity mechanism selection –Malicious alteration –Damage detection –Partial reconstruction with self-embedded data

19. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 19 Major Risks and Planned Mitigation Risk –Partial recovery of subsets may not be very practical (too resource-intensive or error-prone) Mitigation –Focus research on more efficient or economical damage detection and less on partial recovery –Devise policies that control the allowable expenditure of resources

20. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 20 Accomplishments to Date Prototype Tool –Demonstrates hierarchical subset methods Watermarking methods Some initial results on policy tradeoff analysis

21. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 21 Quantitative Metrics Metrics that may be used are –Size of DSI mark –Time to apply integrity protection –Time for partial reconstruction techniques –Robustness of method

22. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 22 Expected Major Achievements If successful, these methods will provide –A more effective method for data integrity detection and data reconstruction –A better foundation about how to relate integrity policy objectives with integrity mechanisms

23. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 23 Task schedule First version of prototype tool: Feb 2000 Next version: July 2000 Final version: December 2000

24. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 24 Key outstanding issues and recommended resolution None

25. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 25 Transition of Technology Military transition –Integrity enhancement for expensive transmissions, e.g., air-to-ground targeting data –Use of integrity technologies such as self-embedding for steganography (information hiding) –Using embedded info to trace unauthorized disclosure Possible commercial transitions –Injection of key technologies into WetStone’s SMARTWatch integrity checker

26. Copyright 2000, Odyssey Research Associates, Inc. SL00-0003 26 What do you need from the DARPA PM? No pending requirements