DoS-Resilient Secure Aggregation Queries in Sensor Networks

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DoS-Resilient Secure Aggregation Queries in
Sensor Networks

• Haifeng Yu
• National University of Singapore
• http//www.comp.nus.edu.sg/yuhf

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Background Secure Aggregation Queries

• Sensor networks often queries for aggregate
  information
• Predicate count, sum, avg, etc
• Usually obtained via in-network aggregation
• Need for security
• Malicious sensors may report arbitrary readings
  not much we can do
• Malicious sensors may manipulate other sensors
  readings want to prevent this

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Previous Work and Our Goal

• Chan06,Chan07,Yang06
• Enables the detection of an incorrect result
  user will then reject the result
• But, attacker can keep corrupting the result and
  cause result to be rejected ? DoS attack!
• Analogy Safety without liveness
• Our goal Secure and highly-available aggregation
  queries
• Tolerate the attacker instead of just detect it
• This talk will use predicate count as an example

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Protocol One Set Sampling (Broadcast Sampling)

• Sampling More robust that aggregation
• Challenge If count is b, then samples needed
  to obtain an approximation is
• Solution Set sampling (Broadcast sampling)
• Sample a set of sensors in a single sample
• Leverages special properties of sensor networks

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Protocol Two Verifiable Aggregate Synopsis

• Light-weight detection-only protocols
• But maintain audit trails
• Adopt ideas from duplicate-insensitive counting
• Failure-free message complexity
• FM synopsis Flajolet85
• Exp synopsis Mosk-Aoyama06
• Generate audit trails when under attack
• Pinpointing protocol can later revoke malicious
  sensors