Unformatted text preview: all of the radios and televisions are operating when the plaintext/ciphertext pair is broadcast. Finally, everyone would have to be instructed to call a Central-Party-Whatever-It’s-Called if a key ever shows up on their screen, and then to read off the string of numbers appearing there. Table 7.2 shows the effectiveness of the Chinese Lottery for different countries and different key lengths. China would clearly be in the best position to launch such an attack if they have to outfit every man, woman, and child with their own television or radio. The United States has fewer people but a lot more equipment per capita. The state of Wyoming could break a 56-bit key all by itself in less than a day. Biotechnology If biochips are possible, then it would be foolish not to use them as a distributed brute-force cryptanalysis tool. Consider a hypothetical animal, unfortunately called a “DESosaur” . It consists of biological cells capable of testing possible keys. The plaintext/ciphertext pair is broadcast to the cells via some optical channel (these cells are transparent, you see). Solutions are carried to the DESosaur’s speech organ via special cells that travel through the animal’s circulatory system. The typical dinosaur had about 1014 cells (excluding bacteria). If each of them can perform a million encryptions per second (granted, this is a big if), breaking a 56-bit key would take seven ten-thousandths of a second. Breaking a 64-bit key would take less than two tenths of a second. Breaking a 128-bit key would still take 1011 years, though. Table 7.2 Brute-Force Cracking Estimates for Chinese Lottery Time to Break Country China U.S. Iraq Israel Wyoming Winnemucca, NV Population 1,190,431,000 260,714,000 19,890,000 5,051,000 470,000 6,100 # of Televisions/Radios 257,000,000 739,000,000 4,730,000 3,640,000 1,330,000 17,300 56-bit 64-bit 280 seconds 20 hours 6.9 97 seconds hours 4.2 hours 44 days 5.5 hours 58 days 160 15 hours days 48 days 34 years (All data is from the 1995 World Almanac and Book of Facts.) A...
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This note was uploaded on 10/18/2010 for the course MATH CS 301 taught by Professor Aliulger during the Fall '10 term at Koç University.
- Fall '10