Question 1
Accepting payment information introduces significant security and reliability considerations
for the system's design and organizational processes. Outline two (2) security and reliability
considerations you would consider when designing a system that accepts payment
information.
[4 marks]
Question 2
Outline three (3) costs reliability and security risks that can be introduced by outsourcing the
payment functionality of a system to a third party.
[6 marks]
Question 3
Differentiate between initial velocity and sustained velocity. How do the two (2) concepts
impact and influence the design of security and reliability in secure systems? [6 marks]
Question 4
Designing a system to be understandable, and maintaining that understandability over time,
requires effort. Outline three (3) reasons why understandability is important in secure system
design.
[6 marks]
Question 5
Explain what unmanaged complexity is? How does unmanaged complexity impact the
understandability of a system?
[4 marks]
Question 6
Outline two (2) disadvantages of allowing arbitrary rollbacks in a secure system design.
[4 marks]
Question 7
The Slashdot effect, also known as slashdotting, occurs when a popular website links to a
smaller website, causing a massive increase in traffic. This overloads the smaller site, causing
it to slow down or even temporarily become unavailable. This has the same effect as a denial-
of-service attack, albeit accidentally. To avoid these cascading failures, you can design your
system to instead degrade gracefully. Outline three (3) ways you can design your system to
respond by degrading gracefally.
[ 10 marks]
2