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Opportunistic Encryption: A Trade-Off between Security and Throughput in Wireless Networks
October-December 2007 (vol. 4 no. 4)
pp. 313-324
Wireless network security based on encryption is widely prevalent at this time. However, encryption techniques do not take into account wireless network characteristics such as random bit errors and fading. For example, we note that properties such as the avalanche effect that make a block cipher secure also cause them to be sensitive to bit errors. Therefore, there is a fundamental trade-off between security and throughput in encryption based wireless security. Further, if there is an adversary with a certain attack strength present in the wireless network, we see an additional twist to the security-throughput trade-off issue. In this paper, we proposed a framework called opportunistic encryption that uses channel opportunities (acceptable signal to noise ratio) to maximize the throughput subject to desired security constraints. To illustrate this framework and compare it with some current approaches this paper presents the following: (a) mathematical models to capture the secuity-throughput trade-off; (b) adversary models and their effects; (c) joint encryption and modulation (single and multi-rate) optimization; (d) the use of forward error correcting (FEC) codes to protect encrypted packets from bit errors; and (e) simulation results for Rijndael cipher. We observe that opportunistic encryption produces signficant improvement in the performance compared to traditional approaches.

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Index Terms:
Security, integrity, and protection, Data encryption, Data Encryption, Wireless communication, Security and Privacy Protection, Optimization, Emerging technologies, Simulation, Algorithms, Cost/performance, Wireless systems, Dynamic programming
Mohamed A. Haleem, Chetan N. Mathur, R. Chandramouli, K.P. Subbalakshmi, "Opportunistic Encryption: A Trade-Off between Security and Throughput in Wireless Networks," IEEE Transactions on Dependable and Secure Computing, vol. 4, no. 4, pp. 313-324, Oct.-Dec. 2007, doi:10.1109/TDSC.2007.70214
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