Reply To: 8b

[The-Letter-Wriggler]

(Harry maybe you will put this up late today or early Wednesday)

For those last few who have not yet figured out 8B

Form the ciphertext into 41 Rows of 35 letters
Take each row at a time and perform a Columnar Transposition
on each of them with the 5 letter (or digit) key.

To do 8B with pencil and paper:

Here is the 1st 35 letters

OUEVEBEKCOAAFEOITIBEHIAKUTNOTQDRHKR

take the 1st letter then every 7th letter
cross out the letter as you copy it, do not
count crossed out letters. Whenever you reach
the end of the 35 letters start over again.
Continue until all letters are crossed out.
(this is a modular transposition 7 mod 35)

As you obtain the letters write them out into 7 lines of 5 letters like so

okoit
uciaq
eotkd
vaiur
eabth
bfenk
eehor
01234

swap the columns accoring to the number key
(column 3 above becomes column 0 below etc.)

34021
itook
aquic
kdeto
urvia
theba
nkbef
orehe
01234

Straighten out for the first line of plaintext:

itookaquickdetourviathebankbeforehe

Now you have to repeat all the above on each of the rest of the other 40 rows.
This is the ‘gotcha catch’, you cannot decrypt all the ciphertext at once.
Tedious and time consuming but it gets the job done.