Choosing a Password

A system allows the user to choose a password with a length of one to

Eight characters, inclusive. Assume that 10,000 passwords can be tested

Per second. The system administrators want to expire passwords once they

Have a probability of 0.10 of having been guessed. Determine the expected

Time to meet this probability under each of the following conditions.

1. Password characters may be any ASCII characters from 1 to 127,

Inclusive.

1. Password characters may be any alphanumeric characters (“A”

Through “Z,” “a” through “z,” and “0” through “9”).

1. Password characters must be digits.
2. Q2. A. when the characters on a Password are any ASCII characters from 1 to 127,

   C = the number of letters in the alphabet

   N = the sum number of passkeys

   R = the guessing frequency (104 scaled to the suitable time entity)

   T = refers to the set number of attempts expected before breaking the passkey.

   Therefore, (T x R) / N = 0.10, the sum of the numeral attempts of the passkeys is the odds one out of ten (1/10). The sum number of passkeys is N = S-1 = 80iicc—119.

   For that reason, C = 127, and T = 6.82 x 1011 seconds, which is equal to 21,629 years.

    

   1. When the Password characters are in any alphanumeric characters, which may be from (“A” to “Z,” “a” to “z,” and “0” to “9”).