SOFTWARE SECURITY AND RELIABLILITY IN AVIATION

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SOFTWARE SECURITY AND RELIABLILITY IN AVIATION

• Everett Hite

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What is Reliability?

• Fault tolerance
• Failure rate
• Minimizing Risk

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Why is Reliability Important in Aviation?

• Human Life
• Economic Cost
• Intangibles faith and perception

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Example
Ariane 5 Flight 501
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Overview

• Background
• Current Approaches
• Security
• Effectiveness
• Conclusions

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Background

• Since 1968Boeing 707 INS
• 1976Concorde SST Flight Controls
• Main Applications
• Avionics
• Control Systems

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Background (Contd)
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Background (Contd)
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Background (Contd)

• How much reliability?
• How is it measured?

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Current Approaches

• Strong Design and Review
• Probability
• Impact
• Rating A D
• Criteria
• Review

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Current Approaches (Contd)

• As a rule multi-versioning
• Redundancy
• Computer
• Physical
• Airbus A320
• Dual version voting system
• SEC
• 3, 1 per spoiler pair and elevator hydraulic
  control
• ELAC
• 2, one per aileron/elevator hydraulic pair

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Current Approaches (Contd)

• Limitations
• Usable mechanical backup controls
• Reliance on multi-versioning
• Do not fail independently (Knight Levenson)

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Security

• Little information available
• Primarily physical security
• System access outside cockpit?
• Maintenance/Diagnostic Interfaces
• Wiring
• Control overrides?

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Effectiveness

• Difficult to determine
• Statistics
• Fatalities to flights
• Fatal accidents to flights
• Does not include unreported incidents

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Effectiveness (Contd)
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Effectiveness (Contd)
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Conclusions

• Positive record thus far
• Aviation safer than ever before
• Must not stop improvement
• Future directions
• Development/validation of novel reliability
  measures
• Incorporate security into design process

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Summary

• Background
• Current Approaches
• Security
• Effectiveness
• Conclusions

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Thanks

• Vipul Gupta
• Thema Davis

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Life can only be understood backwards, but it
must be lived forwards. - Soren Kierkegaard