Introduction — what this topic is and why it matters
This lesson connects five closely-linked exam themes: who the attackers and defenders are (hacker types and ethical hacking), what the crimes look like (cybercrime and its prevention), the law of the land (Bangladesh's Digital Security Act 2018 and Cyber Security Act 2023, plus the 2016 Bangladesh Bank heist), how money moves securely online (electronic payment systems, the SET protocol and digital signatures), and how organisations govern security (policy vs standard vs guideline vs procedure, risk types, audit, disaster recovery and business continuity).
For BCS, Bank (Officer/IT), and IT-officer written and viva exams these are among the highest-yield "current + conceptual" topics. Questions are often single-fact ("Which Act replaced the Digital Security Act 2018?") or scenario/definition based ("Difference between RTO and RPO", "What is a grey-hat hacker?"). Master the definitions, the dates, and the small comparison tables and you can answer almost anything asked here.
Learning objectives
- Classify hackers (white, black, grey, script kiddie, hacktivist) and state what ethical hacking is.
- List the phases of penetration testing in order.
- Define the major cybercrimes — phishing, identity theft, ransomware, cyberstalking — and their prevention.
- State correctly the name, year and status of Bangladesh's Digital Security Act 2018 and Cyber Security Act 2023.
- Recount the key facts and figures of the 2016 Bangladesh Bank heist.
- Explain electronic payment systems and their types, the SET protocol, and the role of digital signatures.
- Distinguish policy, standard, guideline and procedure; and inherent, residual and control risk.
- Compute and interpret RTO and RPO for a data centre and differentiate DRP from BCP.
- Design a multi-layer secure e-banking architecture (DMZ, WAF, TLS, 2FA, IDS).