SST 2022 S4 Computing Prelim P1 Ans

1 2022 SEC 4 COMPUTING PRELIM EXAM MARKING SCHEME Qn 1 Marking Scheme / Answer Draw a line to match the types of computer security threats with their respective descriptions. Description • A computer program that runs automatically and attempts to spread by sending copies of itself to other computers without the need to attach itself to an existing program. • A hidden program that secretly collects personal information about its users and transmits this information to attackers without the users’ knowledge. • The use of emails and fake websites that appear to be from reputable companies in order to steal personal information such as passwords and credit card numbers from users. • A computer program that pretends to be a harmless file or useful application. Once it is run, it does something harmful such as giving intruders unauthorised access to the computer instead. • The interception of requests sent from a computer to a legitimate website and redirection to a fake website to steal personal data or credit card details. • A computer program that attaches itself to a normally harmless program and modifies it. Types of computer security threats (a) Pharming • (b) Spyware • (c) Trojan horse • (d) Worm •

2 Qn 2 Marking Scheme / Answer (a) Media Access Control (b) They allow all devices to be uniquely identified in a network. (c) First six digits: Manufacturer’s identity number Last six digits: Device’s serial number (d) A16 = 10102 D16 = 11012 (AD)16 = 101011012 (e) (BE)16 = 11 × 16 + 14 × 1 = 190 (f) Hexadecimal are used to store intensity values for red, green and blue in RGB colour codes. Hexadecimal are used to express the characters of ASCII/Unicodes. (No marks for just stating RGB or ASCII/Unicode) Qn 3 Marking Scheme / Answer Advantages - - Technology has enabled more exciting and engaging forms of entertainment. Many computer games have active online communities and mobile games have even managed to bring participants together in the real world through in-game incentives to meet or team up. - - AI has also made it possible to provide more accurate recommendations for consumers based on collected data of their previous choices of entertainment. - - Games, animation and media are areas of strong growth in the entertainment industry with new opportunities being opened up by the rise of high-quality virtual reality, augmented reality and motion-tracking technology. - - Many businesses are also using monitoring technology and strategies from game design to provide rewards and incentives for work-related achievements. Disadvantages - - Some people may be addicted to computer games or social networking sites - - There is an increasing concern that such technology is causing people to become deficient in real-life social skills or abandon their responsibilities - - AI has also made it possible for anyone to create doctored images and videos that appear remarkably convincing to the average viewer. Wh