Smash Guard: A Hardware Solution to Prevent Security Attacks on the Function Return Address

A buffer overflow attack is perhaps the most common attack used to compromise the security of a host. A buffer overflow can be used to change the function return address and redirect execution to execute the attacker\u27s code. We present a hardware-based solution, called SmashGuard, to protecting the return addresses stored on the program stack. SmashGuard protects against all known forms of attack on the function return address pointer. With each function call instruction a new return address is pushed onto an extra hardware stack. A return instruction compares its return address to the address from the top of the hardware stack. If a mismatch is detected, then an exception is raised. Because the stack operations and checks are done in hardware, and in parallel with the usual execution of call and return instructions, our bestperforming implementation scheme has virtually no performance overhead. While previous software-based approaches\u27 average performance degradation for the SPEC2000 benchmarks is only 2.8%, their worst-case degradation is up to 8.3%. Apart from the lack of robustness in performance, the software approaches\u27 key disadvantages are less security coverage and the need for recompilation of applications. SmashGuard, on the other hand, is secure and does not require recompilation, though the OS needs to be modified to save/restore the hardware stack at context switches, and when function call nesting exceeds the hardware stack depth

The burden of allergic rhinitis and asthma

Asthma and allergic rhinitis are common health problems that cause major illness and disability worldwide. The prevalence of allergic rhinitis is estimated to range from 10% to 20% in the USA and Europe. Multiple factors contribute to the wide range of reported prevalence rates. These include type of prevalence rate reported (current or cumulative), study selection criteria, age of participants, differences in survey methods, varied geographic locations and socioeconomic status, any of which are significant enough to confound direct comparison between studies. There is no standard set of diagnostic criteria for allergic rhinitis. In most studies, the criteria for diagnosis are based on the subject’s reporting, solely by questionnaire and rarely confirmed by skin testing. In addition, most studies focus on hay fever, leaving perennial allergic rhinitis underestimated. Sinus imaging is generally not performed and, therefore, rhinosinusitis not differentiated. Some investigators report ‘current’ prevalence while others report ‘cumulative’ or ‘lifetime’ prevalence. Epidemiologic studies have consistently shown that asthma and rhinitis often coexist in the same patients. The prevalence of asthma is <2% in subjects without rhinitis while it varies from 10% to 40% in patients with rhinitis. Furthermore, the majority of patients with asthma experience rhinitis, which is a factor in the risk for asthma. Despite recognition that allergic rhinitis and asthma are global health problems, there are insufficient epidemiologic data and more data are needed with regard to their etiologic risk factors and natural history. This aim of this review is to enable the reader to discuss prevalence, risk factors and prognosis of allergic rhinitis and asthma

Quality of life in allergic rhinitis

Allergic rhinitis is a global health problem that causes major illness and disability worldwide. Although nasal and nonnasal symptoms are directly attributable to inflammation in the upper respiratory tract, individuals also experience generalized symptoms that include fatigue, mood changes, depression, anxiety and impairments of work and school performance, and cognitive function. Health-related quality of life focuses on patients’ perceptions of their disease and measures impairments that have a significant impact on the patient. The burden of disease, as the patient perceives it, forms the basic motivation to seek medical aid or to undergo therapy. Adherence to therapy requires changes in health, perceived by patients as relevant and outweighing eventual disadvantages of intervention. Because so many factors are involved in health-related quality of life, there are multiple ways in which it can be measured. A variety of validated and standardized questionnaires have been developed including assessments of school performance, work performance, productivity, and other parameters that quantify the impact of allergic rhinitis and its treatment on quality of life. The aim of this review is to highlight the impact of allergic rhinitis on the quality of life and to analyze the most commonly used health-related quality of life instruments

A new horizon in the treatment of biofilm-associated tonsillitis

Objective: To demonstrate the efficacy of tonsil brushing in patients with chronic tonsillitis to remove the microbial biofilm on the tonsil surface using an in vitro model. Design: Specimens from patients undergoing tonsillectomy were evaluated prior to and following surface cleaning methods, including rinsing and brushing, using scanning electron microscopy (SEM). Patients: The study population consisted of 25 randomly selected patients with chronic tonsillitis. Interventions: Specimens were collected and divided into four portions. Each portion received distinct surface cleaning methods and was immediately fixed for SEM examination. Outcome measures: The biofilm layer on the surface of the tonsils was examined using SEM. The density of the biofilm layer and the degree of persistence of the biofilm after rinsing and brushing were measured. Results: The surface biofilm of the tonsils in the first group, which were neither brushed nor rinsed, revealed a thick layer of biofilm on the mucosal surface. The second group of tonsils, which were only rinsed, also showed a thick layer of biofilm. The third group of tonsils, which were rinsed following gentle brushing using a soft toothbrush, showed a reduction in the thickness of the biofilm layer. The fourth group of tonsils, which were brushed with a hard brush, was almost devoid of a biofilm layer. Conclusion: Our results demonstrate that rinsing does not effectively remove the biofilm layer on the tonsil surface. The use of a harder brush was identified as a more powerful means of removing biofilm compared with a soft brush