COMPUTER ETHICS AND SECURITY
CRYPTOGRAPHY AND ENCRYPTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Original methods of encryption (such as the Caesar Cipher) do not need the use of a key
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Data can be encrypted using ciphers and decrypted using a key
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Users cannot read or understand encrypted data without the use of a key
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The Caesar Cipher is an example of a substitution cipher
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Detailed explanation-1: -2) Which of the following cannot be chosen as a key in the Caesar cipher? Explanation: In Caesar cipher, we can choose a number or a character which when performed addition modulo operation with the given letters of the plain text gives us ciphertext. However, a string cannot be chosen for encryption in this case.
Detailed explanation-2: -The Caesar cipher is based on transposition and involves shifting each letter of the plaintext message by a certain number of letters, historically three, as shown in Figure 5.1. The ciphertext can be decrypted by applying the same number of shifts in the opposite direction.
Detailed explanation-3: -Disadvantages of Caesar cipher It can be easily hacked. It means the message encrypted by this method can be easily decrypted. It provides very little security. By looking at the pattern of letters in it, the entire message can be decrypted.
Detailed explanation-4: -Because there are only 25 possible keys, Caesar ciphers are very vulnerable to a “brute force” attack, where the decoder simply tries each possible combination of letters.