Systems and models for secure fallback authentication

Fallback authentication (FA) techniques such as security questions, Email resets, and SMS resets have significant security flaws that easily undermine the primary method of authentication. Security questions have been shown to be often guessable. Email resets assume a secure channel of communication and pose the threat of the avalanche effect; where one compromised email account can compromise a series of other accounts. SMS resets also assume a secure channel of communication and are vulnerable to attacks on telecommunications protocols. Additionally, all of these FA techniques are vulnerable to the known adversary. The known adversary is any individual with elevated knowledge of a potential victim, or elevated access to a potential victim's devices that uses these privileges with malicious intent, undermining the most commonly used FA techniques. An authentication system is only as strong as its weakest link; in many cases this is the FA technique used. As a result of that, we explore one new and one altered FA system: GeoPassHints a geographic authentication system paired with a secret note, as well as GeoSQ, an autobiographical authentication scheme that relies on location data to generate questions. We also propose three models to quantify the known adversary in order to establish an improved measurement tool for security research. We test GeoSQ and GeoPassHints for usability, security, and deployability through a user study with paired participants (n=34). We also evaluate the models for the purpose of measuring vulnerabilities to the known adversary by correlating the scores obtained in each model to the successful guesses that our participant pairs made

Outcome of 49 Iraqi adult patients with Chronic Lymphocytic Leukemia treated with oral alkylating agent:

Background: Chronic lymphocytic leukemia (CLL) is a heterogeneous disease with an extremely variable course. Survival after diagnosis can range from months to decades and wide variability exists in the rate of disease progression and the incidence of disease-related complications among patients with CLL. Staging helps to define prognosis and to decide when to initiate therapy. Objective: To asses response to oral alkylating therapy and to evaluate the adverse events that can complicate the disease itself or the treatment, including infections, autoimmune and other complications. The survival events are also been assessed. Patients and methods: Forty nine Iraqi CLL patients, their age ranged between 40-90 years were followed with median duration of 28 months. During the follow up period of these patients, the events that complicated the disease or therapy were recorded. The primary endpoints were response rates, quality of response, Secondary endpoints of the study were overall survival , progression-free survival and event free survival. Response rates were calculated for 40 patients who were treated for at least 6 months. All patients were treated with intermittent pulse therapy of oral single alkylating agent. Results: The majority of patients recruited either had intermediate or advanced stage disease in 45(91%) patients .Autoimmune phenomena, were documented in 5(10.2%)patients. There was increased incidence of infections with either viral or bacterial pathogen, complicating the course of disease in 20 (40.8%). Remission state was mainly with partial response in 26/40(65%).In12(24.4%) patients the disease progressed and death occurred in 6(12.2% ) patients ,4(8.1% )of them were CLL(related) and 2(4.08%)of them unrelated(stroke, ischemic heart disease) to CLL with median progression free survival(PFS)and overall survival(OS) for these patients were not reached, with 2 years PFS and OS were70%. Conclusion: Although CLL is an indolent disease still the course is complicated by many events like autoimmune problem and infections whether related to CLL or to treatments. Alkylating agent were effective therapy in the treatment of CLL and the majority of patients in this study partially responde

SYNTHESIS AND UTILITY OF NEW POLYCYCLIC COMPOUNDS AS POTENTIAL ANTIMICROBIALS BASED ON CHROMENE MOIETY

Objective: The present research aims to synthesize some new polycyclic compounds including chromene moiety and study their antimicrobial activity. Methods: Several new polycyclic systems including chromene scaffold incorporated with pyridine, pyrimidine, imidazopyrimidine, and imidazodiazocine were achieved via condensation reaction of chromene derivative under the proper condition with various reagents namely; cyanothioacetamide, phenyl isothiocyanate, malononitrile, carbon disulfide, benzaldehyde, triethyl orthoformate, and 1,4-dichlorobutane. Moreover, a chlorodiazenyl chromene derivative was reacted with some substances possessing active–CH2-bridge such as ethyl cyanoacetate and malononitrile to end up with hydrazono compounds. Such compounds were eventually cyclized with hydrazine hydrate to form pyrazole and oxopyrazole derivatives. Moreover, compound 1 was treated with benzoyl acetone, and then followed by cyclization with malononitrile to provide the corresponding 2-amino14-(4-methoxyphenyl)-4-methy-5-phenyl-14H-benzo[5,6] chromeno [2,3H][1,6]naphthyridine-3-carbonitrile (20). Results: The results of the antimicrobial screening in vitro revealed that the inhibition zone (mm) of the synthesized compounds 1-3, 5 and 8 implied their optimum antibacterial activity, while the compounds 4, 6 and 9-13, 15 showed a moderate to weak antibacterial activity against multiple species of B. subtilis, S. aureus, E. coli and P. aeruginosa. In contrast, the compounds 1, 6, 11, 15 showed high antifungal activities against different species of A. flavinand C. albicans, while the other compounds exhibit a moderate to poor antifungal activity. Conclusion: It is remarkable that a series of chromene derivatives synthesized by a simple and available method leads to a molecule of promising antimicrobial activity. Further research is recommended to approve the importance of polycyclic systems for various applications