Assignment:
A computer system uses passwords constructed from the 26 letters (a to z) or 10 integers (0 to 9). Suppose there are 10000 users on the system with unique passwords. A hacker randomly selects (with replacement) passwords from the potential set.
A) There are 9900 users with unique 6 character passwords on the system and the hacker randomly selects 6 character passwords. What is the mean and standard deviation of the number of attempts before the hacker selects a user password?
B) Suppose there are 100 users with unique 3 character passwords on the system and the hacker randomly selects 3 character passwords. What is the mean and standard deviation of the number of attempts before the hacker selects a user password?
C) Which system is more secure the 6 character or the 3 character password protected system?
Provide complete and step by step solution for the question and show calculations and use formulas.