Xiaocong Jin

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This paper presents TIGHT, a geographic routing protocol for cognitive radio mobile ad hoc networks. TIGHT offers three routing modes and allows secondary users to fully explore the transmission opportunities over a primary channel without affecting primary users (PUs). The greedy mode routes a packet via greedy geographic forwarding until a PU region is(More)
The plummeting cost of Bluetooth tags and the ubiquity of mobile devices are revolutionizing the traditional lost-and-found service. This paper presents SecureFind, a secure and privacy-preserving object-finding system via mobile crowdsourcing. In SecureFind, a unique Bluetooth tag is attached to every valuable object, and the owner of a lost object submits(More)
Crowdsourced spectrum sensing has great potential in improving current spectrum database services. Without strong incentives and location privacy protection in place, however, mobile users will be reluctant to act as mobile crowdsourcing workers for spectrum sensing tasks. In this paper, we present PriCSS, the first framework for a crowdsourced spectrum(More)
The deep penetration of tablets in daily life has made them attractive targets for keystroke inference attacks that aim to infer a tablet user’s typed inputs. This paper presents VISIBLE, a novel video-assisted keystroke inference framework to infer a tablet user’s typed inputs from surreptitious video recordings of tablet backside motion. VISIBLE is built(More)
Dynamic spectrum access is the key to solving worldwide spectrum shortage. The open wireless medium subjects DSA systems to unauthorized spectrum use by illegitimate users. This paper presents SpecGuard, the first crowdsourced spectrum misuse detection framework for DSA systems. In SpecGuard, a transmitter is required to embed a spectrum permit into its(More)
Dynamic spectrum access (DSA) is the key to solving worldwide wireless spectrum shortage. In a DSA system, unlicensed secondary users can opportunistically use a spectrum band when it is not used by the licensed primary user. The open nature of the wireless medium means that any secondary user can freely use any given spectrum band. Secondary-user(More)
The H.264/AVC video coding standard shows high coding efficiency compared to previous video coding standards by applying new coding features. However, due to the exhaustive Rate-distortion optimization (RDO) based mode decision process, the computational complexity of the encoder greatly increases. In this paper, a fast mode decision algorithm for spatial(More)
Mobile device losses and thefts are skyrocketing. The sensitive data hosted on a lost/stolen device are fully exposed to the adversary. Although password-based authentication mechanisms are available on mobile devices, many users reportedly do not use them, and a device may be lost/stolen while in the unlocked mode. This paper presents the design and(More)
Dynamic spectrum access (DSA) has great potential to address worldwide spectrum shortage by enhancing spectrum efficiency. It allows unlicensed secondary users to access the underutilized licensed spectrum when the licensed primary users are not transmitting. As a key enabler for DSA systems, crowdsourced spectrum sensing (CSS) allows a spectrum sensing(More)