The demand for smartphones and mobile based applications is growing very fast since past few years. Thousands of applications on Google Play store received millions of downloads. The growing smartphone functionalities have increased its energy requirements. The applications provide amazing features and rich user interfaces, make use of hi-tech sensors leading to high power utilization. Many such application contains various kinds of power bugs which leads to unnecessary processes running in the system. There is large scope to optimize power utilization in smartphones. This paper identifies various components in smartphones that utilize power causing unnecessary power wastage in the system. It highlights various subsystems proposed by researchers in order to optimize power consumption in smartphones.

In this paper, we present a systematic study of how to make a browser secure. Web browser is vulnerable to different attacks; these attacks are performed due to vulnerabilities in the UI of the web page, Browser cache memory, extensions, plug-in. The Attacker can run malicious JavaScript to exploit user system by using these vulnerabilities. Buffer overflow attack, Cross-site-scripting, Man-in-the-middle, Extension vulnerability, Extreme Phishing, Browser Cache poisoning, Session hijacking, Drive-by-download, Click-jacking attacks are discussed. Browser with electrolysis system and sandboxed processes are discussed to prevent the browser from attack.

Security issue in cloud computing is an active area of research. Thousands of users are connecting to a cloud daily for their day to day work. Unfortunately they are ignorant about the risk involved while doing transactions on the internet. End user systems as well as cloud based data centers must be able to overcome the threats due to Viruses, Trojan and Malware etc. This paper highlights the major security threats in cloud computing system and introduce the most suitable countermeasures for these threats. Threats are classified according to different perspectives, providing a list of threats. In this article some effective countermeasures are enlisted and discussed. General TermsNetwork security, Cloud security.

In today's internet world, Malicious and malfunctioning contents from the internet are regular problems for host systems such as Smartphones, Desktops, Clouds etc. Almost all underlying operating systems provide security from most of the threats. However, we need to add some extra defense to our system. Sandboxing is an important security technique that lets programs run in its isolated environment. A sandbox is a tightly controlled environment where programs run. It provides access to a tightly controlled set of resources for programs, such as memory, scratch space on the disk, network access, and input devices. A program running in the sandbox has just as many permissions as it needs without having additional permissions that could be misused. Sandbox restricts a program to access resources outside the sandbox. Sandbox prevents malicious or malfunctioning programs from accessing rest of the system. Nowadays, most of the mobile operating systems, desktop applications like web browsers, browser plugins, document viewers and cloud computing systems are using sandboxing mechanism to run applications. For the implementation of the sandboxing mechanism, software vendors rely on underlying operating system security features. There are different ways and approaches that can be used to implement sandbox mechanisms. This paper highlights the Linux security features such as Chroot, Cgroups, Capabilities, SCI, Namespaces, Seccomp, Resource Limit, LSMs such as SELinux, Virtualization and grsecurity that can be used in the implementation of the sandboxing mechanism.