 Computer security, cybersecurity, or ID security is the protection of computer systems from theft or war damage to their hardware, software or electronic data, as well as from disruption or misdirection of the services they provide. The field is of growing importance due to increasing reliance on computer systems, the Internet and wireless networks such as Bluetooth and WIFI, and due to the growth of smart devices, including smartphones, televisions and the various tiny devices that constitute the Internet of Things. Due to its complexity, both in terms of politics and technology, it is also one of the major challenges of contemporary world. This financial damage has been caused by security breaches, but because there is no standard model for estimating the cost of an incident, the only data available is that which is made public by the organizations involved. Several computer security consulting firms produce estimates of total worldwide losses attributable to virus and worm attacks and to hostile digital acts in general. The 2003 loss estimates by these firms ranged from $13 billion worms and viruses only to $226 billion for all forms of covert attacks. The reliability of these estimates is often challenged, the underlying methodology is basically anecdotal. Security breaches continue to cost businesses billions of dollars but a survey revealed that 66% of security staffs do not believe senior leadership takes cyber precautions as a strategic priority. However, reasonable estimates of the financial cost of security breaches can actually help organizations make rational investment decisions. According to the classic Gordon Loeb model analyzing the optimal investment level in information security, one can conclude that the amount a firm spends to protect information should generally be only a small fraction of the expected loss i.e., the expected value of the loss resulting from a cyber slash information security breach.