摘要：This paper presents an in-depth understanding of Availability, which is one of the important pillars of Information Security and yet is not taken too seriously while talking about the security of an information system. The paper highlights the importance of Availability w.r.t. Security of information and the other attributes of security and also gives a realistic shape to the existing CIA triad security model. An in-depth understanding of the various factors that can impact the Availability of an information system (Software, Hardware and Network) is given. The paper also gives a categorization of the type of Availability that a system can have. The paper also explains the relation between Availability and other security attributes and also explains through what issues an information system may go while providing Availability.
