Cryptology - Unofficial St. Mary's College of California Web Site

10.13. EXERCISES 215
Several codewords were in use: VENUS for colonel, WAYLAND for captured,
ODOR for Vicksburg, NEPTUNE for Richmond, ADAM for President, NELLY for
4:30pm. The message was also enciphered as a complete rectangle.
With these hints (that the South didn’t have), can you decrypt the message
16. Break the double transposition UELOB DARES RNIOI STOBE LIYVA APSRN
TALWY ALE Hint: the word double appears in it.
17. [Hassard] One of the favorite enciphering techniques during the controversy
following the presidential election of 1876 was transposition ciphers
on words with the important tell-tale words (people’s names, state names,
etc.) being replaced by (often) proper nouns, usually geographical names.
(In the messages below, however, the names of the states in question –
Florida, Louisiana and Oregon – are un-encrypted.) Then the entire message
was transposed, using words as units.
Fortunately for the decrypters, there were a very large number of dispatches.
A very common word was Warsaw, and a lucky guess confirmed
this stood for telegram. The short ciphertext
Warsaw they read all unchanged last are idiots cant situation
is then fairly easily seen to read
Cant read last telegram. Situation unchanged. They are all idiots.
This provides the key (47296381015), meaning, take the 4th work of the
plaintext, put it first in the cipher, followed by the 7th word or the plaintext,
then the 2nd word, and so on.
This ordering helped decrypt most messages of ten words, but not others.
However, it was noticed that the telegrams always came in word lengths
that were multiples of five. Perhaps each length had its own key If so,
multiple anagramming on a selection of ciphers of the same length should
lead to their decryption.
In Figure 10.5 are five messages, written in column form, with their words
numbered. Dispatch 1 has adjourned until to-morrow. The only possible
noun is London, so 29, 27, 19, 28 must be part of the key. Using
this order in Dispatch 2 gives us out if a. Looking at the words in Dispatch
2, intend to count us out if a seems reasonable. So now the
key must contain 25, 5, 10, 29, 27, 19, 28.
This is an example of multiple anagramming – using a reasonable
ordering of one text to help understand the ordering of another, and visa
versa. Use multiple anagramming to decrypt this message.