An ethical hacker, also referred to as a white hat hacker, is an information security expert who systematically attempts to penetrate a computer system, network, application or other computing resource on behalf of its owners. The purpose of ethical hacking is to evaluate the security of and identify vulnerabilities in systems, networks or system infrastructure. It includes finding and attempting to exploit any vulnerabilities to determine whether unauthorized access or other malicious activities are possible.
An ethical hacker is required to randomly guess the correct pin code that consists of the number 0 through 9 that must be entered in the correct order to access a company system.
1. What is the probability that the ethical hacker will guess the pin code correctly on the first try?
2. There are many variations of this guess. Assuming the primary variation allows the ethical hacker to guess correctly if the four-digit in the number are selected in any order as long as they are the same four digits as set by the IT security of the company.
For example, if the ethical hacker picks four digits making the number 2376, then the he will guest it right if 2376, 3726, 6327, 7632, and so forth, are entered. Consider the following four different versions of his presumptions.
(a) All four digits are unique (e.g. 1234)
(b) Exactly one of the digits appears twice (e.g. 2334, 8185)
(c) Two digits each appear twice (e.g. 1212, 8855)
(d) One digit appears three times (e.g. 2226, 8188)
Find the probability that the ethical hacker will successfully guess the accurate pin code in the first try for each of these four situations.
Show the necessary steps and explanation for the four presumptions stated above.