Secret Writing Devices

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In this activity about encryption, learners cut out a secret decoder badge from a handout and use it to encode messages to each other. They can also create their own codes that are different from the given ones on the handout, so that no one else in the group can read their messages. The activity includes an extension activity where strips of paper are wrapped around pencils and other round objects to recreate the scytale (pronounced side-uh-lee), a Roman encryption device. [Activity is publicly available through a web crawler capture on]

Quick Guide

Preparation Time:
10 to 30 minutes

Learning Time:
30 to 45 minutes

Estimated Materials Cost:
1 cent - $1 per student

Age Range:
Ages 8 - 14

Resource Types:
Activity, Lesson/Lesson Plan


Materials List (per student)


  • Engineering and Technology
    • Computing
      • Information Systems
      • Information Technology
    • Technology
      • Information and Communication
  • Mathematics
    • Representation
  • The Nature of Technology
    • Technology and Society
      • Technology and History

Informal Categories

  • Computers


To use this activity, learners need to:

  • see
  • read
  • touch

Learning styles supported:

  • Links STEM to other topics of interest such as arts and humanities
  • Involves hands-on or lab activities


Includes alignment to state and/or national standards:

Access Rights:

  • Free access



Funding Source:

  • National Science Foundation ESI, 0206403