Caesar Cipher exploration with Twitter
1 Hook

Twitter helps students to engage a wider audience of their friends and the public. It provides a group of undefined listerners, an audience. When students encrypt their own name and tweet it, their friends ask questions about it and it provides an evidence of learning. Students can see other tweets within the classroom tag and discuss it. It can be a spring to a Personal Learning Network.
2 Direct Instruction

The concept of encryption and the specific cipher is introduced by Khan Academy https://www.khanacademy.org/math/applied-math/cryptography/crypt/v/caesa...
Students learn what encryption is and how to use the Caesar Cipher. Next students are asked to encrypt their first name.
3 Guided Practice

Students work in small groups to encrypt their own first name and check the encryption of others.
4 Independent Practice

Students check the cipher text of each other and use the encryption algorithm. The algorithm is simple, students move each letter 3 characters to the right in the alphabet. They practice with their own name and ones of their peers.
5 Wrap-Up

Once the students encrypted their own name and checked the work of others in the group they will tweet the result. The faculty can run Twitter search for the class tag or twitterfall.com as a backchannel for the activity.
Here is a sample tweet:
My name in Caesar cipher is Dobvvd #CIS150 #GVSU