Week 2

Question 1

What is a non-executable stack (NX)?

Answer 1

It’s a virtual memory protection mechanism to block shell code injection from executing on the stack by restricting a particular memory and implementing the NX bit.

Question 2

What is Address Space Layout Randomisation (ASLR)?

Answer 2

It’s a computer security technique which involves randomly positioning the base address of an executable and the position of libraries, heap and stack in a process’s address space.

Question 3

What is return oriented programming?

Answer 3

Return-oriented programming (ROP) is a computer security exploit technique that allows an attacker to execute code in the presence of security defenses such as executable space protection and code signing.

Question 4

What are the 5 eras?

Answer 4

1) Mainframe Era - dumb terminals connect to one mainframe
2) Minicomputer Era - an extra layer is added between the mainframe and dumb terminals, with cheaper mainframes called minicomputers.
3) Distributed/PC Era - individuals can compute on computers
4) Client-server Era - internet becomes bigger, greater autonomy for businesses
5) Networked Era - Lots of elements can be connected together

Question 5

What are the 5 key characteristics of cloud?

Answer 5

1) servers and storage can be supplied on-demand without human interaction
2) Standardised access for iPads, iPhones, laptops and all future devices
3) Resource pooling - a cloud provider can invest significantly in resources and subdivide physical resources
4) Rapid elasticity - enterprises can scale up or down e.g. busy periods over Xmas
5) measured service - only need to pay when you use it.

Question 6

What are the four deployment models?

Answer 6

1) public
2) private
3) community
4) hybrid

Question 7

What are the three service models?

Answer 7

1) SaaS (taxi)
2) PaaS (renting)
3) IaaS (leasing)

Question 8

What are the “good” aspects of cloud computing? (5 points)

Answer 8

1) specialist staff
2) uniform platform
3) Data concentration
4) Availability of access
5) Recovery

Question 9

What are the “Bad” aspects of cloud computing?

Answer 9

1) Shared environment
2) trust between enterprises and cloud providers
3) Software isolation
4) data protection
5) Complexity

Question 10

What are the “ugly” aspects of cloud computing?

Answer 10

1) governance
2) Architecture
3) compliance
4) availability
5) resolution