Computer Science: An Overview (13th Edition) (What's New in Computer Science)
13th Edition
ISBN: 9780134875460
Author: Glenn Brookshear, Dennis Brylow
Publisher: PEARSON
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Chapter 3, Problem 47CRP
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Determine the time required to test all possible passwords:
The password consists of string of nine characters from English alphabet.
There are
- To find the number of possible passwords, multiply
The time taken for each password to be tested is “
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An early attempt to force users to use less predictable passwords involved computer-supplied passwords. The passwords were eight characters long and were taken from the character set consisting of lowercase letters and digits. They were generated by a pseudorandom number generator with 215 possible starting values. Using the technology of the time, the time required to search through all character strings of length 8 from a 36-character alphabet was 112 years. Unfortunately, this is not a true reflection of the actual security of the system. Explain the problem.
How many bits of entropy does a password consisting of six randomly-chosen digits have?
How many bits of entropy does a password consisting of a single randomly-chosen digit have?
Chapter 3 Solutions
Computer Science: An Overview (13th Edition) (What's New in Computer Science)
Ch. 3.1 - Identify examples of queues. In each case,...Ch. 3.1 - Which of the following activities require...Ch. 3.1 - Prob. 3QECh. 3.1 - Prob. 4QECh. 3.2 - Prob. 1QECh. 3.2 - What is the difference between application...Ch. 3.2 - Prob. 3QECh. 3.2 - Prob. 4QECh. 3.3 - Summarize the difference between a program and a...Ch. 3.3 - Summarize the steps performed by the CPU when an...
Ch. 3.3 - Prob. 3QECh. 3.3 - If each time slice in a multiprogramming system is...Ch. 3.3 - Prob. 5QECh. 3.4 - Prob. 1QECh. 3.4 - Suppose a two-lane road converges to one lane to...Ch. 3.4 - Prob. 3QECh. 3.4 - Prob. 4QECh. 3.5 - Prob. 1QECh. 3.5 - Prob. 2QECh. 3.5 - If a process in a multiprogramming system could...Ch. 3 - List four activities of a typical operating...Ch. 3 - Summarize the distinction between batch processing...Ch. 3 - Prob. 3CRPCh. 3 - Prob. 4CRPCh. 3 - What is a multitasking operating system?Ch. 3 - Prob. 6CRPCh. 3 - On the basis of a computer system with which you...Ch. 3 - a. What is the role of the user interface of an...Ch. 3 - What directory structure is described by the path...Ch. 3 - Define the term process as it is used in the...Ch. 3 - Prob. 11CRPCh. 3 - What is the difference between a process that is...Ch. 3 - What is the difference between virtual memory and...Ch. 3 - Suppose a computer contained 512MB (MiB) of main...Ch. 3 - What complications could arise in a...Ch. 3 - What is the distinction between application...Ch. 3 - Prob. 17CRPCh. 3 - Summarize the booting process.Ch. 3 - Why is the booting process necessary?Ch. 3 - If you have a PC, record the sequence activities...Ch. 3 - Suppose a multiprogramming operating system...Ch. 3 - Prob. 22CRPCh. 3 - Prob. 23CRPCh. 3 - Prob. 24CRPCh. 3 - Prob. 25CRPCh. 3 - Would greater throughput be achieved by a system...Ch. 3 - Prob. 27CRPCh. 3 - What information is contained in the state of a...Ch. 3 - Identify a situation in a multiprogramming system...Ch. 3 - List in chronological order the major events that...Ch. 3 - Prob. 31CRPCh. 3 - Prob. 32CRPCh. 3 - Explain an important use for the test-and-set...Ch. 3 - Prob. 34CRPCh. 3 - Prob. 35CRPCh. 3 - Prob. 36CRPCh. 3 - Prob. 37CRPCh. 3 - Each of two robot arms is programmed to lift...Ch. 3 - Prob. 39CRPCh. 3 - Prob. 40CRPCh. 3 - Prob. 41CRPCh. 3 - Prob. 42CRPCh. 3 - Prob. 43CRPCh. 3 - Prob. 44CRPCh. 3 - Prob. 45CRPCh. 3 - Prob. 46CRPCh. 3 - Prob. 47CRPCh. 3 - Prob. 48CRPCh. 3 - Prob. 49CRPCh. 3 - Prob. 50CRPCh. 3 - Prob. 51CRPCh. 3 - Prob. 52CRPCh. 3 - How is the window manager related to the operating...Ch. 3 - Prob. 54CRPCh. 3 - Prob. 55CRPCh. 3 - Suppose you are using a multiuser operating system...Ch. 3 - Prob. 2SICh. 3 - Prob. 3SICh. 3 - Prob. 4SICh. 3 - Prob. 5SI
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- The Caesar Cipher Algorithm was introduced in Week #1. Encryption is the act of encoding a message with the intent of allowing only authorized people the knowledge of how to read that message. An encrypted message can be decoded, allowing the secured content to be read after decryption. Recall that the Caesar Cipher uses alphabets as the primary source of information but shifted a certain number of letters to the left or right as a key to create the encrypted data. The Caesar Cipher is easily hacked because of the simple technique used to build the key that encrypts and decrypts the data. In this lab, the key is the number of alphabets shifted, and the direction is always toward the increasing alphabetical order. This provides 26 ways of encrypting a message and therefore makes it easier to be hacked by guessing the key within the range of 0 - 25. Write the function caesar_hack( ) that takes three parameters: a Caesar Cipher encrypted message, an alphabet list, and the original…arrow_forwardThe Caesar Cipher Algorithm was introduced in Week #1. Encryption is the act of encoding a message with the intent of allowing only authorized people the knowledge of how to read that message. An encrypted message can be decoded, allowing the secured content to be read after decryption. Recall that the Caesar Cipher uses alphabets as the primary source of information but shifted a certain number of letters to the left or right as a key to create the encrypted data. The Caesar Cipher is easily hacked because of the simple technique used to build the key that encrypts and decrypts the data. In this lab, the key is the number of alphabets shifted, and the direction is always toward the increasing alphabetical order. This provides 26 ways of encrypting a message and therefore makes it easier to be hacked by guessing the key within the range of 0 - 25. Write the function caesar_hack( ) that takes three parameters: a Caesar Cipher encrypted message, an alphabet list, and the original…arrow_forwardQuestion 1 Study the scenario and complete the question(s) that follow: Ceasar Cipher The Caesar Cipher technique is one of the earliest and simplest method of encryption technique. It's simply a type of substitution cipher, i.e., each letter of a given text is replaced by a letter some fixed number of positions down the alphabet. For example with a shift of 1, A would be replaced by B, B would become C, and so on. The method is apparently named after Julius Caesar, who apparently used it to communicate with his officials. 1.1 Write a Ceasar cipher algorithm in such a way that a character D is changed to N. Derive the encryption of the other characters accordingly. 1.2 Based on your algorithm, what will be the encrypted code of the message “my mother is not home". End of Question 1arrow_forward
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