The impact of the internet over the last few years has meant fundamental changes in the way we access the information. Though the network security perimeter has crumbled at all levels, the number of users wanting network access has grown. While there are enormous productivity benefits available from increased access, the security risks have greatly increased. Growing threats to security (e.g. phishing, personal identify fraud) and the personal nature of the data make the balance between security, trust and usability vital. Adams and Sasse (1999) identified the importance for security (in particular security mechanisms) of real world cues that enable users to interpret potential security risks in their interaction with sensitive information. Security threats are increasing day by day and to protect security is becoming a major concern. The different types of attacks are shown in Fig 1.
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Fig 1 Security threats- the types of attacks
Source: https://akela.mendelu.cz/~lidak/share/izk/2008/lecture5-security.ppt It is important to provide security mechanisms that ensure that the system’s security goals are enforce despite threats from attackers. The attacks are leaded against security goals such as: - Interruption damages availability - Modification damages integrity - Interception damages privacy - Falsification damages authenticity In fact some real attacks damage more security goals. For example: viruses can violate integrity and availability of PC’s SW equipment. To ensure the confidentiality integrity and availability of information, it is important to identify with whom you are dealing, and that the data you are receiving is trustworthy .So it is important to safeguard the security goals such as confidentiality, availability, integrity, authenticity,