Cryptography: Sending Secret Messages

thingiverse

Students learn about the Caesar Cipher and the Vigene ̀re cipher. They practice encoding and decoding messages using a decoder ring. Print Settings Printer Brand: MakerBot Printer: MakerBot Replicator Rafts: Yes Supports: No Resolution: standard Infill: 10% How I Designed This First I opened the decoder ring found here http://www.thingiverse.com/thing:14891 in TinkerCad. Then I added a rectangular prism and put a hole in the center so that the letters would be visible. Then I made the ring a hole and cut it away from the box [figure 1]. Next I cut out the middle parts, leaving a little part going up on the bottom so to hold the part in place [figures 2 & 3]. figure 1 figure 2 figure 3 Standards CCSS Overview and Background Project: Cryptography: Sending Secret Messages Students get an introduction to cryptography. They learn two ciphers and practice encoding and decoding messages using a decoder ring that is 3D printed. Students will learn what cryptography is and get some practice sending and receiving messages. Students learn the Caesar Cipher and the Vigene ̀re cipher and how to use them. CCSS.Math.Practice.MP1 Make sense of problems and persevere in solving them. CCSS.Math.Practice.MP5 Use appropriate tools strategically. Lesson Plan and Activity Students are introduced to the Caesar Cipher and then they practice decoding a message. They think of why this cipher doesn’t work well. Then they learn the Vigene ̀re cipher and practice decoding a message. Students then figure out how to use the decoder ring with the Vigene ̀re cipher. Finally, they encode a message and trade with another group to decode their message. As an optional extension, students figure out how these ciphers relate to modular arithmetic. Skills Learned Math.Practice.MP1 Math.Practice.MP5 Duration of Lesson This activity should take one day. Preparation No background is needed for this activity. For the extension students should know modular arithmetic. Rubric and Assessment Here is a sample rubric to use with the worksheet. Question (points) 1 (2) 2 (2) 3 (2) 4 (3) 5 (6) Total 15