31. By itself, using a constant repeating key, a simple XOR cipher can trivially be broken using frequency analysis . 32. The school's facilities include a Thales Underwater Systems LOFAR ( Low Frequency Analysis & Recording ) training simulator. 33. The program should use frequency analysis to decode the text ( ie without any clues from the user ). 34. The most effective way to defeat frequency analysis attacks was the polyalphabetic substitution cipher, invented by Alberti about 1465. 35. Once he had the proper pairings, he could then use frequency analysis to figure out the actual plaintext letters. 36. Saskia's code breaking talent leads her to discover that this task requires simple knowledge of frequency analysis ( cryptanalysis ). 37. In his book, Al-Kindi gave a detailed description of how to use statistics and frequency analysis to decipher encrypted messages. 38. Common letters and symbols would appear more often on the chain, according to the frequency analysis of the likely input. 39. One was a very simple ( by modern standards ) letter-group frequency analysis ( which is just a few counters ). 40. A frequency analysis ought to throw some light on that . talk ) 17 : 47, 9 June 2009 ( UTC)
