Transcript Slides from Talk (MS Powerpoint)

Concede Nothing Protect Everything
Secure Processors:
Design, Pitfalls & A Few Hacks
Steve Weingart
[email protected]
561-394-5086
Concede Nothing Protect Everything
Our Business

Crypto Accelerators

Security Protocol Software

Secure Processors

Combinations of The Above
Concede Nothing Protect Everything
What is A Secure Processor?

A Programmable, Secure, Cryptographic Coprocessor
 Standard Programming Environment inside, Bus and/or Network
Attachment to the Outside
 Secure
 Tamper Resistant
 Tamper Detecting
 Tamper Responding
 Crypto Support
 Algorithms (DES, 3DES, RSA, EC, AES, RC4, etc)
 Protocols (CryptLib, SSL, CCA, etc)
 HW Random Number Generator, RTC, etc.

Commercial Work Started with IBM in the 80’s
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Secure Processors


Create a ‘Trusted Agent’ in the Hostile Field
 The ‘Real Thing’ Doing the ‘Right Thing’
Platform to Build High Security Applications.
 Programmable, to Support Arbitrary Applications
that Need Crypto, Privacy and/or Integrity
Concede Nothing Protect Everything
Secure Processor Block Diagram
Ethernet
D
R
A
M
Serial
uProc
F
L
A
S
H
B
B
R
A
M
C
T
R
L
R
T
C
Local Bus
Crypto
& Interface
Module
Bus
Interface
R
N
G
Physical Security
Circuitry
Battery
PCI, Cardbus, USB, etc.
Physical Security
Boundary
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What Can A Secure Processor Do?
 Intellectual property protection
 Personal Firewall / Remotely Managed
 Credit card personalization
 Kerberos master key protection
 Certification authorities
 e-postage meters
 Electronic currency dispensers
 Secret algorithms
 Electronic payments
 Secure timestamps
 Electronic benefits transfer
 Software usage metering
 Electronic securities trading
 VPN
 Banking transactions
 Hotel room gaming
 Server-based smart card
substitutes
 Advanced Navy destroyer systems control
 Home banking
 Secure Database Access Control
 Pay TV
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Security Requirements, High Level

Most Common Requirements From NIST FIPS PUB 140-1 & -2
 Many Items are Really Assurance Issues

Tamper Detection
 50 uM Maximum Undetected Hole Size (Goal)

Tamper Response
 Must Clear All Sensitive Data

Environmental Failure Protection/Testing
 Voltage
 All Supplies (High & Low)
 Battery too
 Temperature (High & Low)
 Radiation

Must do All of the Above on Power Supply or Battery (& During Transition)
 Protection circuitry is Activated at Factory
 Stays Active for the Life of the Product
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Interactive Considerations

Everything Has to Run on the Battery
 Must Have Reasonable Battery Life
 Must Have Sufficient Power to Respond to Tamper

Defenses have to ‘Cover Each Other’
 I.E. Unusual Considerations for Tamper Response
 Temperature
 Back Powering

Transients During Power Up/Down are Part of Normal Conditions

No False Positives or False Negatives

It has to be Manufacturable too
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Tamper Detection
 Must Detect Very Small Holes!
 Detector is a Grid of Printed Conductors on a Flexible Substrate
 2 Layers
 One pattern on Each Side of Each Layer
 The Detector is Wrapped Around and Glued to the Package
 It is Activated in the Factory and Stays Active for the Product
Life
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Tamper Detection
Metal Shield
Tamper Detecting Membrane
Circuit Card
Inner Cover
Potting
Shielded Base Card
Flexible Data/Power Cable
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Tamper Detection
Test
Outside Layer
Lines on Top
Lines on Bottom
V+
V+
Inside Layer
Test
Same Pattern
GND
Interleaved on
Top and Bottom
GND
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Basic Detection Circuit
Vcc
+
_
Input
+
_
GND
Output
1 = OK
0 = !OK
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The Power Transient Problem
Big Problem!
Vth upper
Input
Vth lower
0V
Time
T power switch
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Environment Failure Protection
 Uses Basic Detection Circuit to Measure Parameters
 Non-damaging Conditions: Cause Reset
 Low Voltage
 High Temperature (Above Operating, Below Storage
Limit)
 Damaging and/or Security Risk Conditions: Cause Erasure
 High Voltage (Above Storage)
 High Temperature
 Low Temperature
 Battery Voltage
 Ionizing Radiation
 These are Really Assurance Issues
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Tamper Response

Need to Erase Secret Data When a Tamper Is Detected
 Not Allowed any Permanent or Violent Actions
 But it Still Has to be Fast

Removing Power and Shorting the Power Pin Works Well
 Reasonably Fast
 Reasonably Sure
 Not Permanent or Violent

Provided…..
 There are No Imprinting Conditions
 The Temperature has to be High Enough
 The Unit has Not Been Irradiated
 The Power Supply has Been Smooth
 The Memory has Not Been Constant for Too Long
 No Back Powering !!!!!
Concede Nothing Protect Everything
Now for the Hacks

Most Physical Attacks are Just Too Hard, so the Hacks are Smarter
 FIB Might Just Change That
 Repair of Blown Debug/Run Fuse is Still Common, But Less So With New IC
Technology

Clocking
 Clock Glitching can Cause Unexpected Actions
 DES Short Loop

Reset
 Reset Glitching can Cause Unexpected Actions
 Incomplete Reset

Power Glitching


Power Glitching can Cause Unexpected Actions
 It can Also Cause Imprinting of RAM Contents
Power Analysis
 Determine Data/Secret Parameters by Analysis of Icc
Concede Nothing Protect Everything
Lock Picking
 Popular Hobby in Security (as are other puzzles :-)
 Gets a Vacationing Office Mate’s Desk Open Quickly
 I Have Softcopy of “The MIT Guide to Lock
Picking” for those who would like to see it.
 Street Sweeper Bristles Make the Best Lock Pick
Material and are Available Everywhere
 Have Fun
Concede Nothing Protect Everything
Questions?
Concede Nothing Protect Everything
Thanks!
Steve Weingart
[email protected]
(561) 394 5086
http://www.cryptoapps.com
Recent Papers:
Physical Security for Computing Systems: A survey of Attacks and Defenses.
Cryptographic and Embedded Systems Workshop, 2000 (Weingart)
Building the IBM 4758 Secure Coprocessor. IEEE Computer, 10/2001, pp 57 – 66 (Dyer, et
al.)
Slides, MIT Guide to Lock Picking and Papers Available at: http://www.gulf-stream.net/security.html