Week 12: Random Number Generators

Question 1

What does ‘entropy’ mean in Information Security?

Answer 1

Random bits collected by OS from various hardware sources (ie. mouse position, time, network data)

Question 2

What makes Pseudo-random Number Generator Cryptographically Secure ?

Answer 2

If a polynomially bounded adversary has no way to distinguish it from true random number.

Question 3

What does a Cryptographically Secure Pseudo-random Number Generator do?

Answer 3

Function that takes some input seed and outputs a long random looking string

Question 4

What does a Cryptographically Secure Pseudo-random Number Generator consist of?

Answer 4

• internal state s
• one way function f to take s1 and output s2
• one way function h to take final state and output the output