There are 26 letters in the alphabet. How many distinct passwords could be made (non-case-sensitive) if a password must be 5 characters long and no letter can be repeated?
Question 9 options:
313,950 |
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65,780 |
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7,893,600 |
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11,881,376 |
There are 26 letters in the alphabet. How many distinct passwords could be made (non-case-sensitive) if...
A password consists of 4 letters among 26 lower-case English alphabet letters and 10 digits: 0,1,...,9. (i) How many different passwords that contain at least one digit can be formed? (ii) How many different passwords that contain at least one digit and at least one letter can be formed?
How many different passwords of size 6 can be formed using English alphabet characters if the first letter must be a capital letter and the remaining letters must be lower case? a) 26 * C(25, 5) b) P(26, 5) c) 26 * P(26, 5) d) 26 * C(26, 5) e) P(26, 6)
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....
i. How many 5-letter passwords (letters may be repeated) can be created from the monkey type- writer from Q1 if it is forbidden for a password to begin and end with the same letter? Answer: 11. Using the monkey typewriter from Q1, how many 8-letter words are there consisting of 8 distinct letters that contain the word 'APE' (as 3 consecutive) letters within the 8-letter word? Answer: iii. Suppose that a group of 9 inhabitants of the Island of Knights...
Cryptology 1.4. We now consider the relation between passwords and key size. For this purpose we consider a cryptosystem where the user enters a key in the form of a password. 1. Assume a password consisting of 8 letters, where each letter is encoded by the ASCII scheme (7 bits per character, i.e., 128 possible characters). What is the size of the key space which can be constructed by such passwords? 2. What is the corresponding key length in bits?...
12. Computer system #1 requires logon passwords to be eight upper-case letters. How many different passwords are there for system #1? Computer system #2 requires logon passwords to be eight characters, which may be upper or lower-case letters, the numbers 0 through 9, and the characters $, #, and %. How many different passwords are there for system #2?
A 5-character password must start with a letter followed by 4 digits. How many passwords are possible? (Digits and letters may be repeated).
A system requires passwords be made up of upper and lower case letters, digits, and punctuation symbols. How many bits of entropy are in a 6 character password? A 12 character password? Suppose your password is three 6-character words, made up of only lowercase letters. How much entropy is in such a password???
QUESTION 6 A password consists of 5 alphabet letters, case insensitive. In the worst case, how many combinations does a hacker must try in order to break the password using brutal force? Write your answer in exact integer.
Answer the questions below. (a) To log on to a certain computer account, the user must type in a 5 -letter password. In such a password, no letter may be repeated, and only the lower case of a letter may be used. How many such 5 -letter passwords are possible? (There are 26 letters in the alphabet.) (b) A pizza parlor has a choice of 12 toppings for its pizzas. From these 12 toppings, how many different 8 -topping pizzas...