Personal computer

About: Personal computer is a research topic. Over the lifetime, 58809 publications have been published within this topic receiving 800814 citations. The topic is also known as: PC.

Interconnectable personal computer architectures that provide secure, portable and persistent computing environments

Abstract: Disclosed are interconnectable personal computer architectures comprising secure, portable and persistent computing environments that provide secure computing sessions with persistence. The computing environments are implemented using a secure non-computing client device, such as a USB device, that interfaces with a host computer and, optionally, a trusted server. The secure non-computing client device is used to instantiate a secure BIOS and a secure cold or warm boot of the host computer, from the client device, in a host protected area of the host computer, or from the trusted server. The client device comprises a security device, such a trusted platform module, that encrypts and decrypts data transferred between the client apparatus and the host computer to provide a sealed computing environment on the host computer. The client device may implement keyboard logger attack prevention. The client device may also implement a high assurance guard to protect applications. The client device may also comprise security wrapper software that encapsulates malware processed by the host computer. Computing methods and software are also disclosed.

Techniques for pairing remote controllers with host devices

Abstract: Techniques for associating a wireless controller to a host device are disclosed. Once associated, the host device is responsive to the associated wireless controller but not responsive to other wireless controllers that may be in the vicinity. Subsequently, if desired, the association with the wireless controller can be removed and a different association with another wireless controller can be invoked. As an example, the wireless controller can be a portable remote controller, and the host device can be a personal computer, a home stereo, a portable media player, or a docking station for a portable media player. In one implementation, the portable remote controller can be an infrared remote controller.

Reproducibility and automatic measurement of QT dispersion.

Abstract: This study investigated interobserver (two observers) and intrasubject (two measurements) reproducibility of QT dispersion from abnormal electrocardiograms in patients with previous myocardial infarction, and compared a user-interactive with an automatic measurement system. Standard 12-lead electrocardiograms, recorded at 25 mm. s−1, were randomly chosen from 70 patients following myocardial infarction. These were scanned into a personal computer, and specially designed software skeletonized and joined each image. The images were then available for user-interactive (mouse and computer screen), or automatic measurements using a specially designed algorithm. For all methods reproducibility of the RR interval was excellent (mean absolute errors 3–4 ms, relative errors 0·3–0·5%). Reproducibility of the mean QT interval was good; intrasubject error was 6 ms (relative error 1·4%), interobserver error was 7 ms (1·8%), and observers' vs automatic measurement errors were 10 and 11 ms (2·5, 2·8%). However QTc dispersion measurements had large errors for all methods; intrasubject error was 12 ms (17·3%), interobserver error was 15 ms (22·1%), and observers' vs automatic measurement were errors 30 and 28 ms (35·4, 31·9%). QT dispersion measurements rely on the most difficult to measure QT intervals, resulting in a problem of reproducibility. Any automatic system must not only recognize common T wave morphologies, but also these more difficult T waves, if it is to be useful for measuring QT dispersion. The poor reproducibility of QT dispersion limits its role as a useful clinical tool, particularly as a predictor of events.

Applying the ISO/IEEE 11073 standards to wearable home health monitoring systems.

Abstract: Objective. The goal of this effort was to investigate the feasibility of applying the ISO/IEEE 11073 (a.k.a. X73) standards, originally intended for bedside monitoring in hospital environments, to wearable, multi-sensor monitoring systems designed for home healthcare. Methods. The X73 upper-layer sub-standards (i.e., nomenclature specification, domain information model, application profiles, and vital sign device descriptions) were adopted and implemented on microcontroller-based sensor hardware to provide plug-and-play medical components. Three types of system elements (base stations, data loggers, and sensor units) perform the functionality required in this standards-based home health monitoring system and communicate using Bluetooth wireless modules. The base station incorporates a LabVIEW interface running on a personal computer. Each data logger and sensor unit is implemented on a microcontroller-driven embedded platform. Sensor units include wearable sensors (e.g., electrocardiograph, pulse oximeter) and nearby sensors (e.g., weight scale, ambient environment sensors). Results. The standards-based prototype system with an open architecture achieves plug-and-play performance suitable for a home environment. Each wireless element in the body/home area network can automatically detect other nearby devices, associate with them, and exchange data with them as appropriate. Conclusions. With minor modifications, the X73 standards can be successfully applied to wearable, wireless, point-of-care systems in the home.

Instant Ciphertext-Only Cryptanalysis of GSM Encrypted Communication

Abstract: In this paper we present a very practical ciphertext-only cryptanalysis of GSM (Global System for Mobile communications) encrypted communication, and various active attacks on the GSM protocols. These attacks can even break into GSM networks that use “unbreakable” ciphers. We first describe a ciphertext-only attack on A5/2 that requires a few dozen milliseconds of encrypted off-the-air cellular conversation and finds the correct key in less than a second on a personal computer. We extend this attack to a (more complex) ciphertext-only attack on A5/1. We then describe new (active) attacks on the protocols of networks that use A5/1, A5/3, or even GPRS (General Packet Radio Service). These attacks exploit flaws in the GSM protocols, and they work whenever the mobile phone supports a weak cipher such as A5/2. We emphasize that these attacks are on the protocols, and are thus applicable whenever the cellular phone supports a weak cipher, for example, they are also applicable for attacking A5/3 networks using the cryptanalysis of A5/1. Unlike previous attacks on GSM that require unrealistic information, like long known-plaintext periods, our attacks are very practical and do not require any knowledge of the content of the conversation. Furthermore, we describe how to fortify the attacks to withstand reception errors. As a result, our attacks allow attackers to tap conversations and decrypt them either in real-time, or at any later time. We present several attack scenarios such as call hijacking, altering of data messages and call theft.