[Tutor] Columnar Transposition Cipher question

[Luke Paireepinart]

On Mon, Nov 8, 2010 at 5:28 PM, Natalie Kristine T. Castillo
<ncastillo at umail.ucsb.edu> wrote:
> Hi, I need help on how exactly to solve this:
That's nice.

>
> To send secret messages you and your partner have decided to use the
> columnar function you have written to perform columnar transposition cipher
> for this course. You have received the ciphertext EXLYHILOSHOOAETU from your
> friend. You two decide to use the keyword MARS. What message did your friend
> send you? Show your steps and do it by hand.
>

Where's the function you've written?