Computer security has become increasingly crucial with the rise of e-commerce, the computerisation of workplaces, and the availability of e-government services. Systems are vulnerable to various attacks, such as denial of service, unauthorised modifications, and misuse. This course provides a real-world perspective on computer security, aiming for systems that are affordable, usable, and trustworthy, rather than “perfect security.” We will explore recent technical literature on specific computer security topics, including forensic computing, secure systems design tradeoffs, mis-identification threats and defences, ethical security, human factors in security, and software security techniques and vulnerabilities.