1. ECE4112 Smart Card Security Nicholas Dorsey Steven Hurst April 28 2005

2. Smart Cards and Networks What do smart cards have to do with networks? Does small = Secure? The focus of our presentation is on the TI TMS370 smart card that was previously used in pay TV system.

3. History Of Hacking Smart Cards Since inception all US pay TV smart cards have been hacked Early 1990s smart cards made their way into pay TV systems, only to be hacked months later. Each generation of smart card has had increased security features. With each enhancement to security, more robust hacks have been developed. Early hacks made use of write-holes. More modern hacks make use of buffer overflow style attacks.

4. Methods of Attacking Smart Cards Microprobing -Physically attack the microprocessor to facilitate a dump of its contents -Expensive -Requires skill and expensive equipment -Destructive Glitching -Use a device to manipulate the clock speed and voltage to dump the contents of the card. -Devices are cheap (around $50) -May be destructive, and very time consuming Buy trade secrets from developers of the technology

5. Glitching Attacks Clock Bursts -Momentary, rapid increase in clock frequency -Causes instructions to be skipped, because execution routine does not have enough time to finish when the new clock cycle occurs. Voltage Glitch -Momentary drop in voltage from about 4.5V to.5V -Causes instructions to be decoded incorrectly These attacks can occur at the same time

6. Devices used to Attack Smart Cards Called by several names (unloopers, glitchers, card readers) Originally developed to repair corrupted EPROMs In the early 1990s Directv® sent an update to all the smart cards. This caused most hacked cards to enter into an infinite loop on startup. The intention was to end smart card hacking for good by destroying the cards used by hackers. The result was a hacking revolution Two foreign groups emerged with devices to repair the cards called unloopers. Fast Eddie (Dean Love) and VoN (Chris Tarnovsky)

7. Devices Contd The loop was similar to the following Code: 8000: jump $8005 …. 8005: jump $8000 ….. more code The unloopers applied a glitch at address 8005 causing the jump instruction to be skipped, or interpreted as a NOP.

8. Devices The sale of these devices would fund satellite hacking for the next decade As time went on the devices became more precise, and eventually became stand alone devices. Today most glitchers use an Atmel AT90s2313 AVR to control the clock and voltage glitches. Newest generation of smart cards are not susceptible to clock and voltage glitches (directly).

9. How to go from Access to A Hack Dump the card Disassemble ROM and EPROM routines Find code in EPROM that can be modified to give access to what you want If pay TV hack, prevent hashing

10. Pay TV Hacks Two types Activation -cloning your neighbors card to watch TV for free 3Ms -one for all and all for one -modify code in the EPROM to enable all channels

11. What is Hashing Some smart cards have routines that execute programs (hashes) from the data stream. Hashes calculate a checksum of the EPROM and use this checksum as part of video decryption New video packets are sent about every 8 sec If the correct signature is not calculated, then the video cannot be decrypted Anyone have any idea how to defeat a Hash?

12. What you will do in lab Use a smart card programmer to passively get data from a smart card Use glitching features to forcefully gain access to EPROM data Use glitching features to repair corrupted Eprom data Explore different utilities that do the above tasks. (XtremeHU and WinExplorer)

13. News Flash Has the latest security card in use by Directv® been hacked?

14. References www.interesting-devices.com Excellent source for History and ongoing advances in smart card technology.