Crypto Time

The Signet Monthly Challange

By Jeff Thompson

A little bit of explanation is due here, we believe. During the reigning years of Douglas Beeferman as the editor of the Banks of the Boneyard , the newsletter would have a Computer Science or Mathematics related puzzle every month. These puzzles were usually written by Daniel Simms, the Editor's right hand man and The Layout Person.

This year, we are going to attempt to continue the tradition, with SigNet's monthly cryptographic challenge. Take a look for yourself, if this problem seems a little too simple, the next month's one may take you a little longer!

If you would like to submit your own puzzle or problem, please send it (with an attached solution) via email to boneyard@uiuc.edu. The editors will review your submission, and perhaps publish it in one of the next issues of Banks. If your idea is extremely good, we may base a prize-based competition on it!

Finally, it would be nice of you to let us know what you think of this "new" feature of the ACM@UIUC newsletter. Drop a line to the above address, if you like!

SigNET presents its monthly cryptographic puzzle. The first person to respond with the correctly decrypted plain text and the decryption method will receive their name printed in pretty letters in the next issue of the Banks of the Boneyard in the SigNet Monthly Challenge section. All cypher text can be decrypted in finite time (though you may not always think so). Please submit your responses to signet@uiuc.edu. You must email the plain text, the explanation of the decryption method (code is acceptable) and your name.

This is a common cypher that should be relatively easy to break. Three cypher texts are provided.

You must decrypt all three. Each text is encrypted with the same method, so being able to decrypt one should result in the ability to decrypt the others. One piece of plain text is provided, to make the solution a little easier to achieve. I doubt I will be as nice next month.

Plain Text #1:

Pine is not elm. Thank goodness.

Cypher Text #1:

Xqvm qa vwb mtu. Bpivs owwlvmaa.

Cypher Text #2:

Izm gwc i kzgxbwozixpmz?

Cypher Text #3:

Aw epg lql bpm kpqksmv kzwaa bpm zwil?

The Cypher text #1 is the encrypted version of Plain Text #1. In order to win this challenge you must mail in the plain text which corresponds to Cypher Text #2 and #3 as well as a description of the algorithm or code used to solve the problem. This challenge is a warm up exercise soon to be followed by more "interesting" cyphers. Have Fun!