NIST CMVP Physical Security Conference Fault Induction & Environmental Failure Testing (EFT)

1. NIST CMVP Physical Security Conference Fault Induction & Environmental Failure Testing (EFT) September 27, 2005

2. Introduction Definition of Fault Induction Types & Uses Environmental Failure Testing (EFT) EFP vs EFT Attack & EFT Testing Methodology Limited Knowledge Full Knowledge Test Conditions & Equipment Safety Considerations Test Reporting Example Test Case Matrix Example EFT Testing Graph Reporting Testing Results Test Challenges Published Attacks FIPS 140-3 Conclusion Agenda

3. Fault Induction • Fault Induction: device (crypto module) is forced to miscalculate defined operations, skip over required operations, and exhibit other erroneous behaviors enabling an attacker (or tester) to gain access to sensitive data or unauthorized control of the device. • Originally used to test products during development to verify that functions could be performed over a wide range of operational parameters (e.g., temperature, voltage, shock, vibration, clock speed, electro-magnetic, etc.).

4. Environmental Failure Testing Combines several types of fault induction attacks (temp & voltage) Tests performed to ensure that fluctuations outside normal operating ranges for temperature and voltage will not compromise security of cryptographic module Point at which the cryptographic module will fail is unknown so more scrutiny is required. Environmental Failure Protections Cryptographic module contains active mechanisms to monitor and respond to fluctuations (accidental or induced) outside normal operating ranges for temperature and voltage Thresholds are known (e.g when tamper response mechanisms will activate) Easier to perform and collect testing data since ranges are known EFT vs.EFP

5. 200 150 EFP Zeroization Module shutdown and zeroization 100 circuit needs to function correctly EFP Shutdown 50 Crypto “Military” Module Commercial Component Storage Component Crypto Operating and Operating Module Range Transport Range Operating Range Range The zeroization Zero circuit needs to operate beyond what the temperature that the module is specified to either operate or -50 be stored EFP Zeroization -100 EFP Thresholds • EFP circuit needs to be active when power is applied and also when the module is in a dormant state (e.g. with no power applied, during storage, etc.). • Component and module storage & transportation temperature ranges usually extend beyond the normal operating ranges. • Products need to able to be shipped or stored where temperatures can be very cold or very hot (-50 oC to 125 oC). • A design and testing challenge to ensure that EFP protections are robust and functional at temperature extremes that push the operating range of the components.

6. Hire Experts Leverage Known Weaknesses Samples Obtain Information Attack Methodology Limited Knowledge • Attacker obtains as much design information through data sheets, white papers, marketing literature, employees, etc • Physical samples of the module will be obtained • Attacker will leverage any known weaknesses published in any prior analysis • Attacker creates a specialized attack based on modules characteristics • Depending on the degree of difficulty or reward, “hired experts” may be used

7. EFT Methodology Full Knowledge • Similar process as with attack model • FIPS 140-2 specifies: • Temperature range to be tested shall be from -100° to +200° Celsius (-150° to +400° Fahrenheit) • Voltage range to be tested shall be from the smallest negative voltage (with respect to ground) that causes the zeroization of the electronic devices or circuitry to the smallest positive voltage (with respect to ground) that causes the zeroization of the electronic devices or circuitry, including reversing the polarity of the voltages.

8. EFT Conditions • The tester will have access to the production grade version of the module • Additional test jigs are used to enable more convenient access to memory and internal signals for testing purposes • Tester must determine that the testing equipment works correctly. • Performs preliminary tests to exercise the testing equipment • Running a sequence of known commands and inputs • Review log files and other status outputs. • In addition, the tester reviews a log of the equipment calibration and may take additional measures to ensure proper setup. • Is specialized set-up necessary to achieve the desired results (e.g. retrofitting chamber, add’l ventilation, etc) ?

9. EFT – Safety Considerations • The very nature of EFT can be dangerous • High/low temperatures • High/low voltages • Exploding products • Fire • Toxic Exhausts • etc • Is the facility where the tests are being performed properly insured to perform EFT testing? • What do you do if the module explodes and someone gets injured? • Are liability issues addressed? • Safety measures for EFT tests: • Face masks (in some cases, a respirator) for smoke/exhaust • Thick gloves to protect hands against hot or freezing components • Smock for body protection against melted parts • Eye goggles • Eye wash station

10. EFT Testing Equipment Environmental chamber: used to modify the cryptographic module’s temperature; notice the monitoring equipment extending out of the chamber’s side Peripheral chamber equipment: liquid nitrogen may be required to bring the temperature down to cold extremes; notice frozen condensation on pipes

11. EFT Monitoring Equipment Power Supply Multi-meter Smart card Analyzer PCI Bus Analyzer Serial Bus Analyzer Monitoring equipment: a wide variety of monitoring equipment can be used to observe, monitor, and record the activity on each of the physical interfaces supported by the cryptographic module.

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20. Test Reporting

21. Overview of FIPS 140-2 Testing Process Product Profile Workshop Step 1 As required Step Optional Services Compliance Consulting Documentation Workshop Design Changes * Step 2 Design Assessment Algorithm Testing Step 3 Source Code Review Step 4 Operational Testing Step 5 Test Report Submittal NIST Report Queue Step 6 Validation Coordination * Changes done by Vendor

22. Additional EFT Challenges • Interpretation of the captured data and status outputs: • Low level equipment used to monitor and record module’s physical interfaces such as logic analyzers. • Equipment does not tend to present the captured information in a readily intelligible form • Be prepared to analyze the outputs at a very rudimentary level (e.g. looking at triggers, endless streams of ‘0’ and ‘1’, etc.). • Ensure information being gathered can be understood (e.g. via data conversion tables, scripts, etc). • Interpretation of test results: • Module was not designed to withstand the extreme ranges, so it is unknown up front how module will behave during testing. • Can be difficult in some cases to determine module has successfully met the EFT requirements; judgment call made by the accredited laboratory.

23. Sample Published Attacks

24. EFT Considerations for FIPS 140-3 • Incorporate EFT at lower security levels • Different EFT attacks based on level of security • Add additional fault induction attacks • Revisit absolute temperature/voltage thresholds • Incorporate EFT testing into FIPS 140-2 Area 11 • Emphasis on tester safety

25. References • FIPS PUB 140-2 • Optical Fault Induction Attacks: http://www.ftp.cl.cam.ac.uk/ftp/users/rja14/faultpap3.pdf • Spike Attacks, Glitch Attacks, ECMAAS, Conducting temperature attacks, TIVA, Single Event Effect Attacks: http://www.silicon-trust.com/pdf/secure_9/15_ifx_laackmann.pdf • Optical Attack photo: http://www.silicontrust.com/pdf/secure_9/15_ifx_laackmann.pdf • PCI Bus Analyzer photo: http://www.corelis.com/products/PCI_Analyzers.htm • Serial Bus Analyzer photo: http://www.yokogawa.com/tm/dl/serialbus/tm-serialbus_03.htm • Smart Card Analyzer photo: http://www.securetech-corp.com/class3150.html • Explosion Photo: • http://free.pages.at/mzwirn/matrix/lobby-explosion.jpg • Melted Components Photo: http://amol.org.au/recollections/img/photos/a2/h1- 1374.jpg