To date a number of comprehensive techniques have been proposed to defend against buffer over attacks. In spite of continuing research in this area, security vulnerabilities in software continue to be discovered and exploited. This is because the existing protection techniques suffer from one or more of the following problems: high run time overheads (often exceeding 100%), incompatibility with legacy C and C++ code, not sufficiently fine grained randomization of memory layout and the inability to perform randomization at run time rather than compile time or link time or load time. While security through diversity is a promising technique to defend against large scale cyber attacks, existing techniques are susceptible to information leakage and brute-force attacks, in addition to the short comings indicated above. To overcome the above indicated drawbacks, in this paper we propose Function Frame Run time Randomization (FFRR) technique. FFRR offers memory layout randomization at run time and performs randomization at the level of individual variables on the stack.

This paper presents the design process and testing of NaVaSH, a stand-alone software application for conducting online exams.Initially, it starts with depiction of various related softwares and later RGUKT Examination System has taken as the basis and survey results were presented. Next the detailed description of NaVaSH modules along with their new features has explained with the help of intermediate snapshots, activity and usage flow charts. The observations, limitations, and initiated future works has been presented sequentially after the presentation of test results conducted on various class of students.