4023f11ps6a

# 4023f11ps6a - Homework#6 Solutions Due Instructions Use the...

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Homework #6 Solutions Due: October 19, 2011 Instructions Use the Table 1 for exercises 1, 2, 3, 5 and use Table 2 for exercises 4 and 6. 1. Encipher the following proverb using the shift cipher ± ( x ) = x + 11 (mod 26): ALL IS WELL THAT ENDS WELL. I Solution. In the following table, the second row comes from table 1, identifying the letter with its numerical equivalent x , the third row computes y = x + 11 (mod 26), and the fourth row gives the letter equivalent. A L L I S W E L L T H A T E N D S W E L L x 1 12 12 9 19 23 5 12 12 20 8 1 20 5 14 4 19 23 5 12 12 y 12 23 23 20 4 8 16 23 23 5 19 12 5 16 25 15 4 8 16 23 23 L W W T D H P W W E S L E P Y O D H P W W Thus, the enciphered text is LWWTDHPWWESLEPYODHPWW. J 2. Decrypt GVZRVFGURORFGZRQVPVAR, assuming that is was produced by by a shift cipher ± ( x ) = x + k . I Solution. Try diﬁerent values of k until a meaningful statement is found. This occurs if k = 13 and the message is decrypted as TIME IS THE BEST MEDICINE (after spaces between words are inserted. J 3. Encipher the statement of Exercise 1 using the a–ne cipher ± ( x ) = 3 x + 7 (mod 26). I Solution. In the following table, the second row comes from table 1, identifying the letter with its numerical equivalent x , the third row computes y = 3 x + 7 (mod 26), and the fourth row gives the letter equivalent. A L L I S W E L L T H A T E N D S W E L L x 1 12 12 9 19 23 5 12 12 20 8 1 20 5 14 4 19 23 5 12 12 y 10 17 17 8 12 24 22 17 17 15 5 10 15 22 23 19 12 24 22 17 17 J Q

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4023f11ps6a - Homework#6 Solutions Due Instructions Use the...

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