Cypher User Manual


Solving a Polyalphabetic Cipher The display for a polyalphabetic cipher is very similar to that of the monalphabetic cipher. However, themessagefrequencies do not lead to a ready decryption as in the case ofthe monalphabetic cipher. The additional repetition search tool (denoted "XYZ,XYZ" on the toolbar) will display results that may give insight into the length of thekeyword. Once some preliminary guesses are established,set the keywordlength (whose default is one, for monalphabetic ciphers) by clicking onthe keyword length icon on the toolbar, and recalculating the message frequencies for different character positions within the keyword.Different frequencieswithin the keyword will be viewable by selectingthe relative position inthe keyword from the View menu in the main application window. Once a keyword length is selected, all statistical and substitution functions are performed only on multiples of the keyword length from that position. Solving Transposition Ciphers Select "Transposition Cipher" from the main applications Options menu. The program will prompt for matrix dimensions and the display will be reset. The toolbar icons will change to perform inversions, rotations, transposes, and other matrix functions.