Abstract Mobile device manufacturers and operating system developers increasingly deploy MAC address randomization to protect user privacy and prevent adversaries from tracking persistent hardware identifiers. Early MAC address randomization implementations suffered from logic bugs and information leakages that defeated the privacy benefits realized by using temporary, random addresses, allowing devices and users to be tracked in the wild. Recent work either assumes these implementation flaws continue to exist in modern MAC address randomization implementations, or considers only dated software or small numbers of devices. In this work, we revisit MAC address randomization by performing a cross-sectional study of 160 models of mobile phones, including modern devices released subsequent to previous studies. We tested each of these phones in a lab setting to determine whether it uses randomization, under what conditions it randomizes its MAC address, and whether it mitigates known tracking vulnerabilities. Our results show that, although very new phones with updated operating systems generally provide a high degree of privacy to their users, there are still many phones in wide use today that do not effectively prevent tracking.

Many applications make use of the edge devices in wireless sensor networks (WSNs), including video surveillance, traffic monitoring and enforcement, personal and health care, gaming, habitat monitoring, and industrial process control. However, these edge devices are resource-limited embedded systems that require a low-cost, low-power, and high-performance encryption/decryption solution to prevent attacks such as eavesdropping, message modification, and impersonation. This paper proposes a field-programmable gate array (FPGA) based design and implementation of the Advanced Encryption Standard (AES) algorithm for encryption and decryption using a parallel-pipeline architecture with a data forwarding mechanism that efficiently utilizes on-chip memory modules and massive parallel processing units to support a high throughput rate. Hardware designs that optimize the implementation of the AES algorithm are proposed to minimize resource allocation and maximize throughput. These designs are shown to outperform existing solutions in the literature. Additionally, a rapid prototype of a complete system-on-chip (SoC) solution that employs the proposed design on a configurable platform has been developed and proven to be suitable for real-time applications.

Security and privacy are frequently linked for good reason; the more specific information an attacker can gather regarding a person or organization, the more devastating or surgical a targeted attack can be. Armed with this knowledge, many individuals and organizations focus too heavily on protecting privacy while under-emphasizing or entirely neglecting actions which will actually make their systems more secure, a practice known as Security through Obscurity. Such is the case with the Institute of Electrical and Electronics Engineers (IEEE) practice of selling private Organizationally Unique Identifier (OUI) registrations to companies. This feature hides the name and personal information of the company that owns an address block in the IEEE public registry. In this paper, we track the adoption of private address allocation over time and attempt to unmask some of the companies behind this veil. We perform a cursory assessment of collected unencrypted frames transmitted by the devices implementing this practice. We identify that ~86% of observed devices reveal their associated provenance through the content of their unencrypted transmissions, thereby rendering the privacy protection moot. Furthermore, we posit that the practice itself is flawed, inherently drawing unnecessary attention by the public nature of IEEE allocations. Our research reveals the ownership details of private addresses used by critical law enforcement, emergency services, and a variety of physical security systems. The results of our findings have been disclosed with the goal of raising awareness of companies and consumers using products with unsubstantiated security guarantees.

Abstract Media Access Control (MAC) address randomization is a privacy technique whereby mobile devices rotate through random hardware addresses in order to prevent observers from singling out their traffic or physical location from other nearby devices. Adoption of this technology, however, has been sporadic and varied across device manufacturers. In this paper, we present the first wide-scale study of MAC address randomization in the wild, including a detailed breakdown of different randomization techniques by operating system, manufacturer, and model of device. We then identify multiple flaws in these implementations which can be exploited to defeat randomization as performed by existing devices. First, we show that devices commonly make improper use of randomization by sending wireless frames with the true, global address when they should be using a randomized address. We move on to extend the passive identification techniques of Vanhoef et al. to effectively defeat randomization in ~96% of Android phones. Finally, we identify a previously unknown flaw in the way wireless chipsets handle low-level control frames which applies to 100% of devices we tested. This flaw permits an active attack that can be used under certain circumstances to track any existing wireless device.