Security and privacy in online networking, cryptographic application in cloud computing and internet of things and privacy-preserving computing are introduced and approaches to prevent, detect, and respond to cyber-attacks are discussed.
-Cybercrime is one of the major crimes done by computer expert. In this paper, need of cyber security is mentioned and some of the impacts of the cybercrime Cyber security is combination of processes, technologies and practices. The objective of cyber security is to protect program, applications, network, computer and data from attack. This need is even more apparent as systems and applications are being distributed and accessed via an insecure network, such as the Internet. The Internet itself has become critical for governments, companies, financial institutions, and millions of everyday users. Networks of computers support a multitude of activities whose loss would all but cripple these organizations. As a consequence, cyber security issues have become national security issues. Protecting the Internet is a difficult task. Cyber security can be obtained only through systematic development; it cannot be achieved through hazard seat-of-the-pants methods. Applying software engineering techniques to the problem is a step in the right direction. In this paper author introduces security and privacy in online networking, cryptographic application in cloud computing and internet of things and privacy-preserving computing. Approaches to prevent, detect, and respond to cyber-attacks are also discussed.