keysquaresearch -file filename -type type ?-period period? ?-scoretype type? ?-language language? ?-keyword word? ?-addspace?
This program loads keywords from an external dictionary. The dictionary must be laid out as a set of files, with each file containing a list of words (in any order) all of the same length, one word per line. The filenames must start with the string len and end with a 2 digit number describing the length of the words inside the file. For example, the file len04 could contain:
very
that
lean
keys
used
type
foot
mine
eery
flee
The keysquaresearch program looks through every dictionary file and attempts to use each word found as the keyword. The keywords are used to generate keysquares by writing in the keyed alphabet in 48 different routes. Each resulting keysquare is then applied to the cipher and the keysquare with the best digram/trigram frequency count is displayed. If the keyword is already known then the -keyword option can be used to decrypt the cipher quickly.
The default scoring method is to use a sum-of-logs-of-digram-frequencies table. This can be changed to any scoring method supported by the score command. The -language option is used to load a scoring table for the specified language, if such a scoring table exists.
The -addspace option will attempt to locate word boundaries after the final solution has been found. This can be a time and memory intensive process on older computers so it is turned off by default.