COhPy Monthly Meeting

NEW LOCATION: CGI Office Near Polaris & Cleveland

Physical location:
CGI Office
570 Polaris Parkway (2nd floor)
Westerville, OH 43082

Schedule:

6:00 p.m.: Socialize, eat, and drink. Improving will be providing pizza and beverages.

6:30 to 8:00 pm. Main meeting and presentation(s).

Tom Wilcox will be presenting a talk on basic encryption. Following is a note from Tom about the presentation:
I've decided we'll work together to crack some substitution ciphers. If you've not done so before, it's a lot of fun, esp. with friends. This will be a hands-on workshop, so bring your laptops if you'd like to participate. Reminder: we'll use Google Colab, which means as long as you have a Google account and are able to get online during the workshop you don't need to set up anything in advance. I'll spend 5 -10 minutes providing a quick overview of cryptography and cryptanalysis and then we'll jump right in. I'm hoping we'll have time to crack three different types of substitution ciphers, each type trickier than the one before it. I'll explain how the ciphers work, demonstrate techniques for cracking each of them, and then provide encrypted messages for us to crack collaboratively, using the new skills just learned.

You might enjoy looking at James Lyons website, Practical Cryptography, although it is inexplicably down currently. No worries, though, you can look at it easily via The Wayback Machine: https://web.archive.org/web/20250118072757/http://practicalcryptography.com/.

James' website has a great deal of extremely interesting and useful information on classical cryptography and cryptanalysis. In fact, his website is my primary source for our talk/workshop, along with James' superb Python library, pycipher, which is available at https://github.com/jameslyons/pycipher. You may enjoy installing it with pip, but that isn't required.

If you'd like to try your hand at cracking a substitution cipher of medium difficulty, you may enjoy giving this one a try:
ZEXX EZ HVVJ R ZV GZNV WL DZG XZHG. — EZEV

Each letter maps cleanly to some unknown letter, and letters are permitted to map to themselves. For example, 'V' = 'd'. Can you figure out the rest?

We meet on the last Monday of each Month. Presentations are given by members and friends of this group. If you would like to do a presentation (small or large) on a python topic, please contact John Cassidy at jocassid@gmail.com