uring the second world war the British intelligence analysts succeeded in breaking the Enigma code by using a short snippet of familiar communication each day. This familiar phrase enabled the day's key to be broken, and the rest of the day's messages were then decrypted using the key. This is known as what kind of cryptographic attack? a. A chosen plaintext attack. b. A known plaintext attack. c.

Consider the following plaintext message P = Follow us What is the corresponding ciphertext if a Vigenere cipher with key = "easy" is used?  Show your work or upload a photo of your work with your name and in your own handwriting.

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.

45. Encrypt the message “success is not final, failure is not fatal” using a columnar transposition cipher for the given keyword “algebra” (1 6 5 4 3 7 2)..

Which of these encryption techniques does NOT rely on a key? a. Polyalphabetic substitution-based cipher b. Data Encryption Standard c. Monoalphabetic substitution-based cipher d. Transposition-based cipher    No hand written and fast answer with explanation

Describe the differences between a monoalphabetic cipher and a polyalphabetic cipher. Is the Caesar cipher a polyalphabetic cipher?  In one of his cases, Sherlock Holmes was confronted with the following message: Znk yozagzout oy mxgbk. Iusk osskjogzkre Although Watson was puzzled, Holmes was immediately able to deduce the type of cipher. Describe the cipher being used to encrypt this message. Can you decode the message? Is this cipher susceptible to brute-force cryptanalysis?

Alice and Bod have decided to use a symmetric encryption algorithm. They have some assumptions about their messages:- Messages only contain capital letters (i.e. A to Z)- The length of their shared key must be greater than or equal to the length of the plaintext- They assign each letter a number as follows: (A,0), (B,1), (C,2), (D,3),…, (Z,25)Their algorithm combines the key and the message using modular addition. The numerical values of corresponding message and key letters are added together, modulo 26. For example, if the plain text is “HELLO” and the key is “SECRET” then the encrypted message is calculated as following:Since the length of the plaintext is 5, we just need the first 5 letters of the key (i.e. “SECRE”), then for each letter, we should add corresponding letters in both the plaintext and the key modulo 26.Plaintext: H (7) E (4) L (11) L (11) O (14)Key: S (18) E (4) C (2) R (17) E(4)Cipher: Z (25) I (8) N(13) C(2) S (18) Write a program in Python, C/C++ or JavaScript to…