A computer system uses passwords that contain exactly 3 characters, and each character is 1 of the 3 lowercase letters (a, b, c) or 3 upper case letters (A, B, C) or the 5 odd digits (1, 3, 5, 7, 9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the number of passwords for Ω. Report the exact number
A computer system uses passwords that contain exactly 3 characters, and each character is 1 of...
A computer system uses passwords that contain exactly 4 characters, and each character is 1 of the 3 lowercase letters (a, b, c) or 3 upper case letters (A, B, C) or the 5 odd digits (1, 3, 5, 7, 9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the probability that a password contains only numbers given that...
A computer system uses passwords that contain exactly 3 characters, and each character is one of the 26 lowercase letters (a-z) or 26 uppercase letters (A-Z) or 10 integers (0-9). Let Ω denote the set of all possible passwords, and let and denote the events that consist of passwords with only letters or only integers, respectively Suppose that all passwords in 2 are equally likely. Determine the following probabilities. Round your answers to three decimal places (e.g. 98.765). (c) The...
3. A computer system uses passwords that contain exactly eight characters, and each character is one of the 26 lowercase letter (a -z) or 26 uppercase letters (A - Z) or 10 integers (0-9). Let Ω denote the set of all possible passwords. Suppose that all passwords in Ω are equally likely. Determine the probability for each of the following: (a) Password contains all lowercase letters given that it contains only letters (b) Password contains at least 1 uppercase letter...
A company‘s computer system requires passwords to be 7 to 9 characters long, and to consist of uppercase and lowercase letters {A, a, B, b, C, c, . . . , Z, z}, digits {0, 1, 2, 3, . . . , 9} and the special characters {&, #, $, *, +, _}, and to contain at least one special character or digit. How many such passwords are there?
If passwords may contain lower case letters and digits, how many 6-character passwords start with the lower case letter 'a' or ends with the number '3'? Answer:
18. At a certain company, passwords must be from 3-5 characters long and composed of the 26 letters of the alphabet, the ten digits 0-9, and the 14 symbols !,@,#,$,%,^,&,*,().-+,{, and ). (As a note, the password does not REQUIRE at least one character of each type. In other words, it is fine if your password doesn't have any digits or is only special symbols.) a. How many passwords are possible if repetition of characters is allowed? [4 points] b....
A hacker has programmed their computer to generate, uniformly at random, an eight-character password, with each character being either one of 26 lower-case letters (a-z), one of 26 upper-case letters (A-Z) or one of 10 integers (0-9). The hacker wants to infiltrate a website that has 2 million users. Assume, for simplicity, that each user is required to use a unique password. i. What is the expected number of attempts before the hacker successfully generates a user password? ii. What...
Compute the number of passwords of each type below along with how long it would taketo test all possible such passwords if it takes 1 nanosecond to test a password. Report the times in the most convenient human understandable form. In all of these, unless noted otherwise, order matters and repetition of characters is allowed. Passwords of length 8 with any combination of lowercase letters, uppercase letters,and numbers. Passwords that start with a capital letter, have 10 lowercase letters, and...
Question 3: a. A computer password is 6 characters long. A character can be either a digit or an uppercase English letter. A valid password must contain exactly one digit. How many valid passwords are there? (hint: you do not know the position of this one digit. It might be in the beginning or the end or the middle of the password. You may use the combination low to select the position of this digit and then assigno value to...
A computer system uses passwords constructed from the 26 letters (a-z) or 10 integers (0-9). Suppose there are 10,000 users on the system with unique passwords. A hacker randomly selects (with replacement) passwords from the potential set. Round your answers to the nearest integer (a) There are 8,900 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...