Jefferson disk cipher

thingiverse

To fully understand the awesome device got to the wikipedia https://en.wikipedia.org/wiki/Jefferson_disk page I will try to explain it here to the best of my abillity. President Thomas Jefferson is famous for being the person who wrote the declaration of independence, a founding father, and a politician. Well it turns out he was actually an inventor and mathematician(who knew right!). A while back I visited the National cytological museum. For those who don’t know it is a relatively small museum next to the NSA headquarters buildings. It is about the history of cypher and encryption from the revolutionary war to around the cold war. One of the exhibits in the revolutionary war and civil war section was about this device. This is where I got the inspiration from. What really impresses me about this device is that the concept is so simple yet deciphering it is so hard if not close too impossible. The way it works is you turn the disks so that they say on one line the message you want. Then you put the rod through the holes to keep the wheels from turning independently. Rotate all of the disks to a different line and right the message it says there on a piece of paper. So that when the recipient gets the message s/he will turn the disks to say that message on the page and will turn all the disks to where the message is. In the letter not in the code you should write the order of the disks and how many lines away the real message is from your message. The genius behind this can be revealed when looking at other simple ciphers that were introduced before it. For example, if you write the simplest cypher where each letter is represented by another letter or symbol. One can easily crack it by finding words like ‘a,’ ‘all,’ or ‘I’. since if you found a word in the message you were trying to decode that said ‘WMM’ it is almost certainly ‘all’ then you could change all ‘w’s to ‘a’ and all ‘m’s to ‘l’s and so on. Obviously this is not a very good code. Whereas here a single letter can be different every time so a word like ‘all’ would not be recognized. **The picture is of an earlier version that is why it only has eight disks. i haven't had a chance to print it yet but i will post when i have Print Settings Printer Brand: MakerBot Printer: MakerBot Replicator 2X Rafts: Yes Supports: Doesn't Matter Resolution: 0.2 or lower Infill: 20 Notes: If you have the time I suggest you print the wheels on their sides this may take many prints therefore if you don't have time for that print them standing up (you may want to print with supports then) The other parts should be printed on their sides. Post-Printing Assembly Assembly is easy put all the disks on the thicker rod then snap the other side feet on make sure the feet are lined up or it won't stand. How I Designed This I used sketchup Project: Jefferson Disk cipher Title: Jefferson disk cipher: a history and math lesson in one! Overview & Background: A while back I visited the National cytological museum. For those who don’t know it is a relatively small museum next to the NSA headquarters buildings. It is about the history of cypher and encryption from the revolutionary war to around the cold war. One of the exhibits in the revolutionary war and civil war section was about this device. This is where I got the inspiration from. What really impresses me about this device is that the concept is so simple yet deciphering it is so hard if not close too impossible. The way it works is you turn the disks so that they say on one line the message you want. Then you put the rod through the holes to keep the wheels from turning independently. Rotate all of the disks to a different line and right the message it says there on a piece of paper. So that when the recipient gets the message s/he will turn the disks to say that message on the page and will turn all the disks to where the message is. In the letter not in the code you should write the order of the disks and how many lines away the real message is from your message. The genius behind this can be revealed when looking at other simple ciphers that were introduced before it. For example, if you write the simplest cypher where each letter is represented by another letter or symbol. One can easily crack it by finding words like ‘a,’ ‘all,’ or ‘I’. since if you found a word in the message you were trying to decode that said ‘WMM’ it is almost certainly ‘all’ then you could change all ‘w’s to ‘a’ and all ‘m’s to ‘l’s and so on. Obviously this is not a very good code. Whereas here a single letter can be different every time so a word like ‘all’ would not be recognized. This concept is what the famous German enigma was based off of. Objectives: demonstrate Jefferson’s disk cypher introduce the concept of cipher and encryption to your students to have fun! Audiences: Middle and high school students Subjects: Math, history Skills Learned (Standards): A better understanding of the history and practical ramifications of this cypher. Lesson/Activity: Teach your students about President Thomas Jefferson’s Disk cypher. The history, math, etc.… Try other simple codes and demonstrate how they can be easily cracked. Have your students write their own short messages and have other students decipher them and vice versa. Have fun! (you can even talk about the enigma too) Duration: 30- 60 minutes Preparation: Do a little research on the topic (make sure you can answer questions!) get paper and pens for the students to write messages on print it! References: Website that explains it really well!https://en.wikipedia.org/wiki/Jefferson_disk