Computer Security Lecture Notes

COMPUTER SECURITY Definition Physical security refers to the security measures which are applied to an automated information system for achieving the specific aim of safeguarding the integrity as well as the availability and confidentiality of system resources (including hardware, software, firmware, information, data and telecommunication). This definition brings three key concepts that are core in understanding computer security: ● Privacy : This is a dualism consisting of: ○ Data privacy: It means that sensitive or private information is not accessible or revealed to any unauthorized person. ○ Surveillance: It entails individuals having power or power over what information concerning them or which they wish to be kept may be gathered and kept by who and what information should not be revealed and to who. ● Integrity: This includes two related concepts: ○ Data integrity: It ensures that data and apps are altered only with specific permission or in an approved method. ○ System integrity: It is the assurance of a system functioning in the way it was meant to operate without purposely or accidentally tampering off the system to systain its functionality. ● Availability – This assures that there is no lag with the working of the systems or service and no authorized user is refused service. These three concepts are what is called the information security processes, embodying the essential goals to be achieved by both the data security, as well as regarding the information and computing services. Assistance is offered, for example, by the requirements contained in FIPS 199 for the security policy of the system, namely: confidentiality, integrity and availability, describing the objectives surrounding a piece of information and a system of information. NIST Standard FIPS 199 classifies the common approaches for attaining these objectives in relation to information security as meeting the loss of certain security measures as follows: ● Confidentiality: The restriction of free access to and disclosure of information or means of providing personal privacy and protecting proprietary information. Breach of confidentiality is the unauthorized access and acquisition ● Integrity: The protection of information from destruction, corruption and modification, and non-repudiation with respect to the whole information package. Loss of integrity happens when information is changed by unauthorized personnel or information is purposely damaged. ● Availability: Securing access to information and other information system resources and the reliable and timely use of the information. Loss of availability occurs when there is any interruption or obstruction to the tracking or the utilization of information or any information systems. If it is generally accepted that the CIA triad is a sufficient definition of core security concepts, there are still some professionals in the domain of security who advocate for other concepts to elighten completely the picture. Here are two of the most often cited ones: ● Authenticity: The quality of being genuine and reliable verifiable and trusted; the assurance of the transmission, a message, or a message source. Assurance here means checking whether the users are who they claim to be and whether all the information inputted into the system is from authorized external agencies. ● Accountability: The security goal that establishes the need of uniquely associating actions of any entity with that particular entity. This facilitates nonrepudiation, deterrence, fault containment, intrusion detection and avoidance, as well as post-event recovery efforts and any legal prosecution. Because truly secure systems are still not feasible, it will always be necessary to attribute a security breach to an individual. Such systems would require having activity logs in order to assist in the investigation of any security violations as well as in case of disputes over certain transactions.