Mohammad Iftekhar Husain

CD-PHY: Physical layer security in wireless networks through constellation diversity

A common approach for introducing security at the physical layer is to rely on the channel variations of the wireless environment. This type of approach is not always suitable for wireless networks where the channel remains static for most of the network lifetime. For these scenarios, a channel independent physical layer security technique is more appropriate which will rely on a secret known to the sender and the receiver but not to the eavesdropper. In this paper, we propose CD-PHY, a physical layer security technique that exploits the constellation diversity of wireless networks which is independent of the channel variations. The sender and the receiver use a custom bit sequence to constellation symbol mapping to secure the physical layer communication which is not known a priori to the eavesdropper. Through theoretical modeling and experimental simulation, we show that this information theoretic construct can achieve Shannon secrecy and any brute force attack from the eavesdropper incurs high overhead and minuscule probability of success. Our results also show that the high bit error rate also makes decoding practically infeasible for the eavesdropper, thus securing the communication between the sender and receiver.

A Simple Cost-Effective Framework for IPhone Forensic Analysis

Apple iPhone has made significant impact on the society both as a handheld computing device and as a cellular phone. Due to the unique hardware system as well as storage structure, iPhone has already attracted the forensic community in digital investigation of the device. Currently available commercial products and methodologies for iPhone forensics are somewhat expensive, complex and often require additional hardware for analysis. Some products are not robust and often fail to extract optimal evidence without modifying the iPhone firmware which makes the analysis questionable in legal platforms. In this paper, we present a simple and inexpensive framework (iFF) for iPhone forensic analysis. Through experimental results using real device, we have shown the effectiveness of this framework in extracting digital evidence from an iPhone.