Answer the question parts a, b, c and d.

In this question, you are going to compute the number of different possible passwords if the personal information which is given above the first question (a) , is used for such purpose. This computation can be carried out by first identifying a set which representing your password space described below. READ THE FOLLOWING INFORMATION THEN ANSWER A, B, C and D.

Assume that for a man with the following personal information:

Name : John Doe

Date of birth : 12 Oct 1987

Address : 34, Jalan Melintang, Taman Menegak, Puchong, Selangor

Car plate number : PAR560

Favorite colour : blue

With this personal information, assume that the man only choose Name, Date of birth and Car plate number to form the password space. This password space is a set P that contains all the basic elements that can be selected to form a password.

P = { johndoe, John, john, jd, 12, twelve, Oct, 10, 1987, 87, par, 560, Par560, pAr560, }

Since choosing a password is a subjective process, everyone is free to determine which personal information should be included into the password space. In addition, once a piece of information is chosen, password creators also have the freedom to select its variants to form the set P. For example, John Doe only choose Name, Date of birth and Car plate number but not Address and Favorite colour. Furthermore, once Name is chosen, the variants johndoe, JohnDoe, john and jd are selected to form the set P, but doe, JOHNDOE and some other variants are not included.

With this password space, there are many patterns of password formation. Among all, two common patterns are listed as follow:

Pattern 1 : Use any 2 pieces of information to form passwords.

Examples: john560, JOHN560, johnjd, 1987Par560, 1987par.

Pattern 2 : Use full or part of the name and mix with another 2 pieces of information. Examples: 12johndoe1987, 12JOHNDOE1987, JD1987PAR.

Since easier to recall is the reason of using personal information to form passwords, permutations in a basic element is NOT considered as one of the pattern because it is too random. For example : johndoe12 match Pattern 1 above, however 1jodohne2 which formed with the same numbers and alphabets is not accepted.

Now, assume that there is no limit on the length of a password, answer the following questions using this following PERSONAL INFORMATION:

Name : JOHN ODAM OERESRE

Date of birth : 11 Nov 1992

Address : 40, suwop, iaaft, Linfer, China

Car plate number : STY240

Favorite colour : teal

1. List at least 4 of the given personal information, followed by its variants which you may use to form passwords. With this information, form a set that represent the complete password space, P. Identify n(P) and then determine the number of different passwords that can be formed with Pattern 1.

2. How many different passwords can be formed with Pattern 2?

3. Besides Pattern 1 and 2, suggest one password formation pattern based on set P. Discuss how this pattern offers a higher number of different passwords compared to Pattern 1 and 2.

4. Computer security experts suggest that a strong password can be formed by randomly choosing characters from all the alphabets, numbers and 30 symbols listed below:

`~!@#$%^&*()-=+_][{};:/.,?

If the advice is followed, about 5.13218873110 different passwords can be formed. Explain how this number is obtained.

Then, considering that the length of the password of some systems cannot exceed 16 characters, explain why the number of different passwords formed by personal information hardly reaches this number.