Sunday, April 12, 2009

Caesar Cipher

There were three days left before Spring Break and I had just finished a unit in geometry, so rather than start anything new, I decided to teach my geometry kids some cryptography.

Of course this went well, since every kid (and most adults, I would assume) think basic cryptography is cool. We made cipher wheels and talked about the enigma machine and I got the most rapt attention I have EVER received while teaching.

After teaching simple Caesar ciphers (where you basically just shift the alphabet), I challenged the kids to write sentences and told them that I could break any of their codes (there are only 25 possibilities for Caesar ciphers - they're really easy to break - and I told them this, but the kids think I am AWESOME). Messages included:

-Yay! Spring Break is almost here!

-Ms. Twine is crazy

-First period is the best math class

-Math is my favorite subject

And then, I found an anonymous note left on my desk.


Which is, decoded: I decided to take stats.

I have no idea who wrote it, but someone in my fifth period geometry class has decided to take my AP Stats class next year. AND THEY TOLD ME IN CODE. I don’t think it gets cuter than that.


A BCPSS Parent said...

You might think "every kid (and most adults, I would assume) think basic cryptography is cool", but I think it's more a reflection of the enthusiasm you put into the subject that you can draw in 100% of your students.

To me, cryptography is not only cool, but crucial in our life of on-line transactions, bank accounts and the like. I was shocked when my daughter's very cool and very smart science teacher commented on her paper about using computers for cryptography that cryptography isn't very interesting or important to people's day-to-day life. The only thing I can think is that biology teachers don't find anything that doesn't involve a life-form very interesting or important. Now, don't get me wrong, I loved disecting frogs in 9th grade, but really, I find cryptography much more useful.

Smallest Twine said...

I would guess that 95% of the world doesn't know that cryptography is used every day with credit cards, etc.

My students now know that they can use it to write notes to each other in their other classes without the teacher knowing what they're writing.

Uhh.. maybe teaching cryptography wasn't the best idea :)

The Tower of AION said...
This comment has been removed by a blog administrator.