No abstract

A Completely Covert Audio Channel in Android by Sukanya Thakur Exfilteration of private data is a potential security threat against mobile devices. Previous research concerning such threats has generally focused on techniques that are only valid over short distances (NFC, Bluetooth, electromagnetic emanations, and so on). In this research, we develop and analyze an exfilteration attack that has no distance limitation. Specifically, we take advantage of vulnerabilities in Android that enable us to covertly record and exfilterate a voice call. This paper presents a successful implementation of our attack, which records a call (both uplink and downlink voice streams), and inaudibly transmits the recorded voice over a subsequent inaudible call, without any visual or audio indication given to the victim. We provide a detailed analysis of our attack, and we suggest possible counter measures to thwart similar attacks. ACKNOWLEDGMENTS Prof. Mark Stamp, my project guide, has supported me and kept me motivated during multiple hiccups and uncertainties I had been through in this project. He provided me with much needed guidance and information, while showing confidence in me especially at times when, in fact, I myself was uncertain on the outcome of my research and experimentation. I truly appreciate his patience and his encouragements all through this difficult path. His you-can-do-it encouragement and much needed timely tips have helped me develop independent thinking and climb the hill with confidence. Prof. Robert Chun has inculcated in me the urge to develop conceptual clarity through his term paper assignments in his classes that I took during my graduate years in San Jose State. His presentation of key ideas in the most simple possible ways has always helped me see the points through the jargon loaded confusing cluster of literature on a subject. I am thankful to him for accepting to become my committee member. Nikki Benecke Brandt's work on NFC fuzzing in Android has been the source of inspiration to me in deciding to go for this Android based project. She has always made herself available whenever I needed her inputs and help, even when it was a stretch for her during her busy schedule. I am gratified to have her as my committee member. Finally I like to thank Apala, my daughter, for remaining awake with me in the nights, always ready to serve me coffee or tea, and for assisting me by making endless adversary calls during the experimentation. v

Background: Long term intake of high amount of fluoride leads to fluorosis causing metabolic, functional and structural damages affecting many tissues and organs including dental and skeletal manifestations. The liver is the most susceptible organ to fluoride toxicity because of its active and major role in digestion and detoxification. Aim: The present study aims to elucidate the effects of sodium fluoride on hepatic function biomarkers, lipid peroxidation and gene expression of Cu/Zn SOD in albino rats. Materials and Methods: Wistar albino rats were randomly assigned to three groups. The control rats were given 1 ml deionized water orally for 40 days. Groups II and III were administered 300 and 600 mg NaF/kg b.w. /day for the same period. Animals were sacrificed under anaesthesia, liver tissue was excised and used for biochemical and molecular analysis. The level of fluoride and lipid peroxidation (MDA) as well as reduced glutathione (GSH) content was determined. The activities of cytosolic copper/zinc superoxide dismutase (Cu/Zn SOD), aminotransferases (ALT and AST), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) in the hepatic tissue were determined. The analysis of gene expression of Cu/Zn SOD in the liver was determined using Real-time PCR. Results: The results revealed significantly (P<0.0001) higher concentration of fluoride and MDA in the liver of rats exposed to fluoride when compared to control. The GSH content reduced significantly (P<0.0001) in fluorotic rats. The activities of hepatic function biomarkers viz; ALT, AST, LDH and ALP elevated significantly (P<0.0001) compared to the control. An elevation of 108.60% (ALP), 121.45% (AST), 33.77% (LDH) and least 24.40% (ALT) was found in rats treated with 300 mg/L fluoride and maximum elevation of 226.20% (ALP), 211.52% (AST), 57.75% (LDH) and least 56.79% (ALT) was registered in rats exposed to 600 mg/L fluoride in drinking water. The activity of cytosolic Cu/Zn SOD decreased significantly (P<0.0001) in fluorotic rats. Pearson’s bivariate correlation and simple linear regression analysis exhibited strong positive correlation between level of hepatic tissue fluoride and activities of ALT (Pearson r= 0.85), AST (Pearson r= 0.94), LDH (Pearson r= 0.89), ALP (Pearson r= 0.86) and in MDA (Pearson r=0.984) while negative correlations existed between levels of fluoride and GSH (Pearson r=-0.93) as well as activity of Cu/Zn SOD (Pearson r= -0.99). The gene expression of cytosolic Cu/Zn SOD was significantly (P<0.0001) reduced in fluorotic rats. Conclusion: The present study revealed that fluoride declined the antioxidant activity of hepatic Cu/Zn SOD at biochemical as well as molecular level which leads to oxidative stress and tissue damage. This further affirms by increased activities of hepatic function biomarkers in correlation with high fluoride level during experimental fluorosis.

A Completely Covert Audio Channel in Android by Sukanya Thakur Exfilteration of private data is a potential security threat against mobile devices. Previous research concerning such threats has generally focused on techniques that are only valid over short distances (NFC, Bluetooth, electromagnetic emanations, and so on). In this research, we develop and analyze an exfilteration attack that has no distance limitation. Specifically, we take advantage of vulnerabilities in Android that enable us to covertly record and exfilterate a voice call. This paper presents a successful implementation of our attack, which records a call (both uplink and downlink voice streams), and inaudibly transmits the recorded voice over a subsequent inaudible call, without any visual or audio indication given to the victim. We provide a detailed analysis of our attack, and we suggest possible counter measures to thwart similar attacks. ACKNOWLEDGMENTS Prof. Mark Stamp, my project guide, has supported me and kept me motivated during multiple hiccups and uncertainties I had been through in this project. He provided me with much needed guidance and information, while showing confidence in me especially at times when, in fact, I myself was uncertain on the outcome of my research and experimentation. I truly appreciate his patience and his encouragements all through this difficult path. His you-can-do-it encouragement and much needed timely tips have helped me develop independent thinking and climb the hill with confidence. Prof. Robert Chun has inculcated in me the urge to develop conceptual clarity through his term paper assignments in his classes that I took during my graduate years in San Jose State. His presentation of key ideas in the most simple possible ways has always helped me see the points through the jargon loaded confusing cluster of literature on a subject. I am thankful to him for accepting to become my committee member. Nikki Benecke Brandt's work on NFC fuzzing in Android has been the source of inspiration to me in deciding to go for this Android based project. She has always made herself available whenever I needed her inputs and help, even when it was a stretch for her during her busy schedule. I am gratified to have her as my committee member. Finally I like to thank Apala, my daughter, for remaining awake with me in the nights, always ready to serve me coffee or tea, and for assisting me by making endless adversary calls during the experimentation. v