Reply To: Double transposition cipher help
Replying to Flappyasdf’s question #87506: Factoring 1869 gave only a few different values for the number of columns to check. The crib given in Tips got me almost home; however, the number of repeated letters in this crib still left several possible permutations. The scattering of expected cribs throughout the message quickly sorted out the final column order. The pattern contained in the order of columns indicated that there may have been simpler ways to decrypt the message.