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**Unformatted text preview: **Q S T U V W X Y Z IT SC Ox OL GO IN GT OS CH Ox OL KS X(I/J) LV RA PD ML KP LP B(I/J) LV RA =KSX(I/J) LVRAPDMLKPLPB(I/J)LVRA 9) [20] If a cryptosystem has 2 51 possible keys, and you have 800 computers, each which can try 400,000 keys a second, in how many days would you be able to recover the key, assuming that you can immediately recognize when you've attempted decrypting with the correct key? (Assume there are 86,400 seconds in a day.) (800 computers)(400,000 keys/sc/computer) = 320,000,000 (320,000,000 keys/sec)(86,400 sec/day) = 2.7648 x 10 13 keys/day (2 51 keys) / (2.7648 x 10 13 keys/day) = 81 days 10) [10] Given the input 1001011001011100 2 and the permutaTon table below, what would be the output be afer applying our input to the permutaTon table? (Please give your Fnal answer in the ±orm o± a binary number, not a permutaTon table.) PermutaTon table: 1 6 1 1 2 5 1 5 2 1 1 6 1 4 3 1 7 1 3 4 9 8 1 0 0 1 0 1 1 0 0 1 0 1 1 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 1 12 5 15 2 11 6 14 3 10 7 13 4 9 8 0 1 1 0 0 0 0 1 1 0 1 1 1 1 0 Output: 0110000110111100 2...

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- Spring '10
- Guha
- Cryptography, 81 days, 86,400 seconds, 86,400 sec, M P U T E R S E C