10 likes | 123 Views
#. f. K. ¡. ¢. o. e. y. s. #. f. d. ¸. o. n. o. e. s. k. Sensors A, B, C, D have different combination of overlapping keys: A: 1, 4 B: 1, 2 C: 2, 3 D: 3, 4. 1. Stadium with Sensors Deployed. Automatic Camera Feed. Track me every 3s!. I want to know who issued command.
E N D
# f K ¡ ¢ o e y s # f d ¸ o n o e s k Sensors A, B, C, D have different combination of overlapping keys: A: 1, 4 B: 1, 2 C: 2, 3 D: 3, 4 1 Stadium with Sensors Deployed Automatic Camera Feed Track me every 3s! I want to know who issued command. (Malicious mote) I fabricate tracking commands. Let’s do one measurement! Guard moves with an XSM Mote, tracked by RIPS technology 4 2 Google Earth Illustration of Localization System B I am C 3 C A B You are not C, since you don’t have key 3 You are not C, since you don’t have key 2 A B D C ~12 Static XSM Motes (positions known ) I know you are not me. D C C D C I can’t hold many keys. Nor do I like complex computations. (Malicious mote) See what happens with false data. (Malicious mote) I send results in other’s name. Group-based Peer Authentication for Wireless Sensor Networks Taojun Wu, Nathan Skirvin, Jan Werner, Brano Kusy, Akos Ledeczi, Yuan Xue (Vanderbilt University) Motivation Simple Example Analysis • Each key represents a group, a node is in k groups if it contains k keys. When k is equal for all nodes, it needs to satisfy at least: • Unlike existing research, we focus at providing authentication. Hence our scheme does not require equal sized key rings, nor equal sized overlapping groups. Scenario: Dirty Bomb Detection and Localization 1. Critical mission 2. Real-time 3. Constrained resources Key Pre-distribution Sensor A pretends to be C, appends message authentication code (generated with key 1 & 4) to outgoing messages • Sensors have pre-distributed subset of keys, out of key pool; • Node-to-key mapping is publicly available to all sensors; • For the localization scenario, each mote has 4 keys, reducing from ~12, if pair-wise secret keys are used. Measurement Results • App. 2800 B in ROM, 200 B in RAM, including program & assigned keys; • Computation time: 5.3 ms; • Verification time: < 0.1 ms, 1.3~1.4 ms or 2.5 ms, if receiver has 0, 1 or 2 keys in common with sender. Objectives • Meet flexible authentication demands: • Care only overall decision; • Allow uncertainty between few pairs • Enable differentiated influence according to role • Level security assurance among sensors • Provide efficient and effective authentication • Low computation requirement • Less memory space usage System Implementation • We implement a component (MultiMAC) under TinyOS (based on SkipJack in TinySec) • MultiMAC is part of the Dirty Bomb Detection and Localization demonstration (Vanderbilt and ORNL) of IPSN 2006. http://www.isis.vanderbilt.edu/projects/rips/ Acknowledgement This is a collaborative work between Institute for Software Integrated Systems and OAK Ridge National Laboratory.