Multi-Tuple Leakage Detection and the Dependent Signal Issue - - PowerPoint PPT Presentation

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Multi-Tuple Leakage Detection and the Dependent Signal Issue - - PowerPoint PPT Presentation

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion Multi-Tuple Leakage Detection and the Dependent Signal Issue Olivier Bronchain Tobias Schneider Fran cois-Xavier Standaert CHES 2019, Atlanta, USA Olivier Bronchain


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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection and the Dependent Signal Issue

Olivier Bronchain Tobias Schneider Fran¸ cois-Xavier Standaert CHES 2019, Atlanta, USA

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 1 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Table of Contents

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 2 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Content

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 3 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Side-Channel Issue

Crypto P’s C’s

Encryption on physical devices:

◮ Standard utilization Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 4 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Side-Channel Issue

Crypto P’s C’s l’s

Physical Trace

Encryption on physical devices:

◮ Standard utilization ◮ But with any physical signals Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 4 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Side-Channel Issue

Crypto P’s C’s l’s

Physical Trace

Encryption on physical devices:

◮ Standard utilization ◮ But with any physical signals ◮ Possibly containing secret information Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 4 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Side-Channel Issue

Crypto P’s C’s l’s

Physical Trace

Encryption on physical devices:

◮ Standard utilization ◮ But with any physical signals ◮ Possibly containing secret information

Side-channel Attacks:

◮ Known to be hard to prevent ◮ Hard to evaluate as well Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 4 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Side-Channel Issue

Crypto P’s C’s l’s

Physical Trace

Encryption on physical devices:

◮ Standard utilization ◮ But with any physical signals ◮ Possibly containing secret information

Side-channel Attacks:

◮ Known to be hard to prevent ◮ Hard to evaluate as well

Two evaluation approaches:

◮ Attack based ◮ Leakage detection Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 4 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Attack Based Evaluation

Can directly mount attacks:

  • 1. Collect measurements

Crypto P’s C’s

= ?

l’s

Physical Trace

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 5 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Attack Based Evaluation

Can directly mount attacks:

  • 1. Collect measurements
  • 2. Perform an attack

Crypto P’s C’s

= ?

l’s

Physical Trace

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 5 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Attack Based Evaluation

Can directly mount attacks:

  • 1. Collect measurements
  • 2. Perform an attack
  • 3. Retrieve the correct sub-key

Crypto P’s C’s

= ?

l’s

Physical Trace

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 5 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Attack Based Evaluation

Can directly mount attacks:

  • 1. Collect measurements
  • 2. Perform an attack
  • 3. Retrieve the correct sub-key

Crypto P’s C’s

= ?

l’s

Physical Trace This requires:

  • 1. Long measurement period
  • 2. Skilled/expert knowledge
  • 3. Distinguish 1 sub-key within 256

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 5 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto P1 or P2 C1 or C2

1 or 2 ◮ Feed the core with two different

sets of inputs

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto P1 or P2 C1 or C2

1 or 2 ◮ Feed the core with two different

sets of inputs

◮ Record the corresponding traces Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto P1 or P2 C1 or C2

1 or 2 ◮ Feed the core with two different

sets of inputs

◮ Record the corresponding traces ◮ Observe differences between the

two sets

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto P1 or P2 C1 or C2

1 or 2

How does it compare with attack based evaluations:

◮ Shortened measurement period

(Possibly)

◮ No skilled/expert knowledge Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection Based Evaluation

Leakage detection searches for dependency between manipulated data and physical traces.

Crypto P1 or P2 C1 or C2

1 or 2

How does it compare with attack based evaluations:

◮ Shortened measurement period

(Possibly)

◮ No skilled/expert knowledge

A good first check but:

◮ Risk of false positives and false

negatives

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 6 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Content

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 7 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets: .

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time

.

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution

Distributions

.

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test

Distributions Statistical Test

.

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test
  • 4. Observe its binary output

Distributions Statistical Test

No difference found .

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test
  • 4. Observe its binary output

Repeat with more measurements if needed

Distributions Statistical Test

No difference found .

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test
  • 4. Observe its binary output

Repeat with more measurements if needed

Distributions Statistical Test

Difference found .

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test
  • 4. Observe its binary output

Repeat with more measurements if needed

Distributions Statistical Test

Difference found The statistical test can search for difference in:

◮ Means with the Welch’s t-test ◮ Distributions with χ2-test ◮ . . .

.

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection

Find a difference between the two sets:

  • 1. Select a point in time
  • 2. Record traces to observe a distribution
  • 3. Perform a statistical test
  • 4. Observe its binary output

Repeat with more measurements if needed

Distributions Statistical Test

Difference found The statistical test can search for difference in:

◮ Means with the Welch’s t-test =

⇒ Most popular

◮ Distributions with χ2-test ◮ . . .

.

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 8 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test

t-testt-testt-testt-testt-testt-testt-testt-test Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test
  • 4. Observe their binary outputs

t-testt-testt-testt-testt-testt-testt-testt-test No No No No No No No No Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test
  • 4. Observe their binary outputs

t-testt-testt-testt-testt-testt-testt-testt-test No No Yes No No No Yes No Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test
  • 4. Observe their binary outputs

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test
  • 4. Observe their binary outputs

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

Difference found if:

◮ At least one of the tests goes above a threshold Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Leakage Detection: TVLA

The traces contain multiple points in time:

  • 1. Select all the points in time
  • 2. Record traces to observe a distribution
  • 3. Perform independent statistical test
  • 4. Observe their binary outputs

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

Difference found if:

◮ At least one of the tests goes above a threshold ◮ Selected thanks to:

◮ Desired confidence ◮ Number of considered time samples ◮ Assuming independence between them

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 9 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

◮ Impossible to take advantage of multivariate

leakage

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

◮ Impossible to take advantage of multivariate

leakage

◮ Could lead to reduced measurement period

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

◮ Impossible to take advantage of multivariate

leakage

◮ Could lead to reduced measurement period

Independence in the signal is usually not met:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

◮ Impossible to take advantage of multivariate

leakage

◮ Could lead to reduced measurement period

Independence in the signal is usually not met:

◮ Wrong assumption while setting the threshold Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Limitations to TVLA

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

TVLA performs independent t-test:

◮ Impossible to take advantage of multivariate

leakage

◮ Could lead to reduced measurement period

Independence in the signal is usually not met:

◮ Wrong assumption while setting the threshold

◮ Hard to interpret results (especially negative ones)

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 10 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Content

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 11 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: General Idea

t-testt-testt-testt-testt-testt-testt-testt-test Yes No Yes No No Yes Yes No

Approach:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 12 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: General Idea

Multivariate statistical test

Approach:

◮ Replace the independent tests by a single one Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 12 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: General Idea

Multivariate statistical test

Single binary output

Approach:

◮ Replace the independent tests by a single one Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 12 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: General Idea

Multivariate statistical test

Single binary output

Approach:

◮ Replace the independent tests by a single one

Natural canditate: Hotelling’s T 2-test

◮ Do not assume independence ◮ Need to invert a covariance matrix

◮ Not always applicable

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 12 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: General Idea

Multivariate statistical test

Single binary output

Approach:

◮ Replace the independent tests by a single one

Natural canditate: Hotelling’s T 2-test

◮ Do not assume independence ◮ Need to invert a covariance matrix

◮ Not always applicable

Heuristic alternative: D-test

◮ Assume independence

◮ Hard to interpret results

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 12 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

t-test Density = 0.1

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 13 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

t-test Density = 0.2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 13 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

t-test Density = 0.5

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 13 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

t-test Density = 0.9

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 13 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Traces Parameter: Density

Density of informative points:

◮ The proportion of leaking points ◮ t-test showing difference with ∞ of measurements

t-test Density = 0.9

Typical settings:

◮ Protected software: low density, long

traces

◮ Hardware unprotected: high density,

short traces

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 13 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density )

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density ) log( # of measurements)

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density ) log( # of measurements)

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

◮ Both methods suffer from a low density

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density ) log( # of measurements) x4 x4

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

◮ Both methods suffer from a low density ◮ Multi-Tuple more than the TVLA

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density ) log( # of measurements) x4 x4

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Features

From simulations with fixed trace length:

◮ Both methods suffer from a low density ◮ Multi-Tuple more than the TVLA

10 2 10 1 100 103 104

TVLA Multi-Tuple

log( Density ) log( # of measurements) x4 x4

Reduced data complexity with higher density

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 14 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length )

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length ) # of measurements

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length ) # of measurements

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

◮ Both methods take advantage of longer traces

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length ) # of measurements

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

◮ Both methods take advantage of longer traces ◮ Multi-Tuple gains more than the TVLA

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length ) # of measurements x4

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 15 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Multi-Tuple Leakage Detection: Parameters

From simulations with fixed density:

◮ Both methods take advantage of longer traces ◮ Multi-Tuple gains more than the TVLA

100 101 102 103 104 105 106 500 1000 1500 2000 2500 3000 3500

TVLA Multi-Tuple

log( Trace length ) # of measurements x4

◮ Reduced data complexity with the number of time samples ◮ The jointly processed trace size is limited for Hotelling’s test because of

covariance matrix inversion (∼2000):

◮ Possibility to run multiple Hotelling’s tests in parallel

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 15 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios

Crypto P1 or P2 C1 or C2

1 or 2

Two extreme settings:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 16 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios

Crypto P1 or P2 C1 or C2

1 or 2

Two extreme settings:

◮ White Box: everything is

known about the design

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 16 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios

Crypto P1 or P2 C1 or C2

1 or 2

Two extreme settings:

◮ White Box: everything is

known about the design

◮ Black Box: nothing is known

about the design

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 16 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios

Crypto P1 or P2 C1 or C2

1 or 2

Two extreme settings:

◮ White Box: everything is

known about the design

◮ Black Box: nothing is known

about the design

How to perform Leakage Detection in these settings ?

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 16 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: White Box

In White Box:

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 17 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: White Box

In White Box:

◮ Prior information about leaking points

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 17 / 20

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Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: White Box

In White Box:

◮ Prior information about leaking points

◮ Can reduce traces

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 17 / 20

slide-74
SLIDE 74

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: White Box

In White Box:

◮ Prior information about leaking points

◮ Can reduce traces

◮ Can invert the covariance matrix (Hotelling’s T 2-test) ◮ High density

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 17 / 20

slide-75
SLIDE 75

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: White Box

In White Box:

◮ Prior information about leaking points

◮ Can reduce traces

◮ Can invert the covariance matrix (Hotelling’s T 2-test) ◮ High density

P1 or P2 C1 or C2

1 or 2

As a result:

◮ Smaller measurement period ◮ Easy interpretation of the confidence (no ⊥

⊥ assumption)

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 17 / 20

slide-76
SLIDE 76

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-77
SLIDE 77

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-78
SLIDE 78

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-79
SLIDE 79

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

◮ Can’t always invert the covariance matrix

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-80
SLIDE 80

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

◮ Can’t always invert the covariance matrix ◮ Fixed density

P1 or P2 C1 or C2

1 or 2

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-81
SLIDE 81

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

◮ Can’t always invert the covariance matrix ◮ Fixed density

P1 or P2 C1 or C2

1 or 2

As a result:

◮ Possibly larger measurement period Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-82
SLIDE 82

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

◮ Can’t always invert the covariance matrix ◮ Fixed density

P1 or P2 C1 or C2

1 or 2

As a result:

◮ Possibly larger measurement period ◮ Independent assumption needed Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-83
SLIDE 83

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Practical Evaluation Scenarios: Black Box

In Black Box:

◮ No prior information about leaking points

◮ Can’t reduce traces

◮ Can’t always invert the covariance matrix ◮ Fixed density

P1 or P2 C1 or C2

1 or 2

As a result:

◮ Possibly larger measurement period ◮ Independent assumption needed

◮ Heuristic required for confidence level interpretation:

◮ TVLA: too conservative ◮ D-test: too optimistic

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 18 / 20

slide-84
SLIDE 84

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Content

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 19 / 20

slide-85
SLIDE 85

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-86
SLIDE 86

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-87
SLIDE 87

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

◮ Straight forward interpretation of the confidence level ◮ And sometimes reduction the measurement period ◮ Loose intuition about the POIs

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-88
SLIDE 88

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

◮ Straight forward interpretation of the confidence level ◮ And sometimes reduction the measurement period ◮ Loose intuition about the POIs

  • 2. If not, must rely on heuristics:

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-89
SLIDE 89

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

◮ Straight forward interpretation of the confidence level ◮ And sometimes reduction the measurement period ◮ Loose intuition about the POIs

  • 2. If not, must rely on heuristics:

◮ TVLA: too conservative ◮ D-test: too optimistic

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-90
SLIDE 90

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

◮ Straight forward interpretation of the confidence level ◮ And sometimes reduction the measurement period ◮ Loose intuition about the POIs

  • 2. If not, must rely on heuristics:

◮ TVLA: too conservative ◮ D-test: too optimistic

Evaluation Hardness

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20

slide-91
SLIDE 91

Introduction Leakage Detection Multi-Tuple Leakage Detection Conclusion

Conclusion

Physical signals are not likely to be independent across time

  • 1. If applicable, Hotelling’s T 2-test provides:

◮ Straight forward interpretation of the confidence level ◮ And sometimes reduction the measurement period ◮ Loose intuition about the POIs

  • 2. If not, must rely on heuristics:

◮ TVLA: too conservative ◮ D-test: too optimistic

Evaluation Hardness

Thanks !

github.com/obronchain/multituple_leakage_detection

Olivier Bronchain Multi-Tuple Leakage Detection and the Dependent Signal Issue 20 / 20