Measuring of the time consumption of the WLANs security functions

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Measuring of the time consumption of the WLANs
security functions

• Jaroslav Kadlec, Radek Kuchta, Radimír Vrba
• kadlecja_at_feec.vutbr.cz 
• Dept. of Microelectronics
• Brno University of Technology, Faculty of
  Electrical Engineering and Communication
  Technologies, Brno, Czech Republic

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Content

• Introduction
• Measuring scenario
• Results
• WEP 64
• WEP 128
• WPA
• WPA2
• Conclusion

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Introduction

• Wireless digital communication starts to increase
  its prominence for the industrial automation
  domain.
• Still more and more producers of automation
  systems try to offer complete wireless solution.
• Problems with
• harsh noise environment,
• undefined network parameters,
• real-time applications.
• To design remote mechanisms (telemonitoring,
  teleservice etc.) using wireless communication,
  an increasing number of communication
  technologies is available,
• limited by strict quality of service and
  performance requirements.

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Introduction

• Automation application
• Hard real-time
• Soft real-time
• Non real-time
• Standard wireless communication protocols (WiFi,
  ZigBee etc.)
• Communication speed X Security level
• Manufacturers dont provide information about
  time parameters

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Measuring scenario

• Measurement scenario is mixture of
• software based packet sniffers,
• special network development boards.
• For controlling these boards a special software
  was written.
• Lowest network function handling allows us to
  have precise control of all packets in the
  network.
• This packet size 146 bytes (100 bytes payload and
  46 bytes packet header) was determined as an
  optimal value by several tests.

ASUS WL-566gM
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Measuring scenario
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Results

• WEP 64-bit

• Stream cipher RC4
• 64-bit key
• IV 24-bit
• Key 40-bit
• CRC-32 checksum
• Average latency 142 ms.
• Time 12,8 ms

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Results

• WEP 128-bit

• Stream cipher RC4
• 128-bit key
• IV 24-bit
• Key 104-bit
• CRC-32 checksum
• Average latency 146 ms.
• Time 16,8 ms

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Results

• WPA

• RC4
• 128-bit key
• IV 48-bit
• Key 80-bit
• TKIP Wired Equivalent Privacy
• Michael checksum algorithm
• Using sender and receiver MAC addresses
• Average latency 152 ms
• Time 22,3 ms

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Results

• WPA2

• AES block cipher
• 128-bit key
• CCMP (Counter mode with Cipher Block Chining
  Message Authentication Protocol)
• Average latency 177 ms
• Time 47,9 ms

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Results
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Results
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Conclusions

• A sophisticated tool with high precision
  resolution and absolute control of network
  traffic was created.
• Our measured results are unique due to their
  precision.
• Manufacturers of wireless network devices do not
  provide this kind of measurements which are very
  important for real time automation applications.
• We can simply decide for which level of real time
  application measured device can be applied.
• Based on those findings it is possible to develop
  wireless automation system with well defined
  parameters of wireless communication link.

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Thank you for your attention