This problem explores the use of a one-time pad version of the Vigenère cipher. In thisscheme, the key is a stream of random numbers between 0 and 26. For example, if the key is 319 5 . . . , then the first letter of plaintext is encrypted with a shift of 3 letters, the second with ashift of 19 letters, the third with a shift of 5 letters, and so on. a) Encrypt the plaintext sendmoremoney with the key stream9 0 1 7 23 15 21 14 11 11 2 8 9b) Using the ciphertext produced in part (a), find a key so that the cipher text decrypts to theplaintext cashnotneeded

Explanation:

Take a as the 0th index and z as the 25th index.

send shift with key 9017 will give

s=b

e=e

n=o

d=k.

s shift 9 places lands the letter b.

Similarly for more money, the result is jdmsxzpmh.

the ciphertext is "beokjdmsxzpmh"

b)

take the first 4 ciphertext

"beok".

Calculate the shift from b to s which is 17 shifts. thus beok can be decrypted with key 17 0 24 19 to get "send"

thus the resulting key is 17 0 24 19 3 11 5 12 15 14 2 8 17

the major difference between the two is the objective and the reward of the game. candy crush has a puzzle theme with the objective of meeting a specific quota of points or objects, you are able to gain access to the next level and compete with peers on the process. on duolingo the objective is rather different, you are given sets of questions for you to answer for you to move to the next level and as for the reward, you are able to learn available language as this is an app developed to teach the user about other languages.