414-e1-F07 - CMSC 414 F07 Exam 1 Page 1 of 7 Name:_ _ Total...

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CMSC 414 F07 Exam 1 Page 1 of 7 Name:_________________________ _____________________________________________________________________________________ Total points: 60. Total time: 75 minutes. 6 problems over 7 pages. No book, notes, or calculator 1. [14 points] Are n=323 and e=5 valid numbers for RSA. Explain. If you answer yes, obtain the corresponding d.
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CMSC 414 F07 Exam 1 Page 2 of 7 Name:_________________________ 2. [5 points] Recall that a DES encryption operation takes a 64-bit plaintext block and a 56-bit key and produces a 64-bit ciphertext block. Recall also that each DES encryption operation itself consists of a number of iterations, which we shall refer to as basic iterations . For the DES encryption in CBC mode of a plaintext message of N 64-bit blocks, obtain the following (in terms of N): a. Total number of DES encryption operations. b. Size of the output. Explain briefly. c. Total number of basic iterations. Explain briefly.
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Exam 1 Page 3 of 7 Name:_________________________ 3. [6 points] Is there an integer K in the range 1, …, 47 such that K 48 mod-105 is not equal to 1? If you answer yes, produce such a K and the value of
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This note was uploaded on 03/22/2012 for the course CSE 5345 taught by Professor Youngheliu during the Spring '12 term at UT Arlington.

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414-e1-F07 - CMSC 414 F07 Exam 1 Page 1 of 7 Name:_ _ Total...

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