CompSci//Media Arts - Cryptography Examples

Cryptography Examples

Today's Goal

Learn about a few examples
of cryptography in history.

Completed

What is information?
Number Bases
Encoding
Overflow Errors
Encryption vs Encoding

Today

Cryptography in History

Upcoming

Numbers to Letters and Back

Typing Practice

No typing practice today,
maybe tomorrow 🙃

Cryptography & History

When we talk about cryptography, we are talking about hiding a message with encryption.

Every time you use your phone, every time you use the internet, these same concepts and ideas are designed into how our technology works to help protect you and your information. This is used everyday for things like emails, text messages, logging into websites or services, online payments, credit card transactions, and so on. Majority of internet connected communication today relies on cryptography.

Let's learn a little bit about the history and core concepts of cryptography before going further.

crypotgraphy-history-1.mp4

The video mentioned that there are multiple types of ciphers.

When we discuss classical cryptography, we typically divide ciphers into two or three categories; Substitution Ciphers, Transpositional Ciphers, and Concealment Ciphers (aka Steganography, aka Null Ciphers). Some people consider do not consider concealment ciphers/steganography to be a form of cryptography.

In this video, Dr. Jungwoo Ryoo of Penn State (DuBois Campus) discuses Substitution and Transposition Ciphers in more detail. We will look more into Steganography later.

cipher-types-overviews.mp4

TASK - Option 1

There are many ciphers throughout history- you've learned about a few today (as well as last class). With your partner, find examples of 5 different ciphers (don't use any examples from the videos, find your own).

In a document, for each cipher:

tell me its name,
a bit about it,
how it works, and
2 resources where someone could learn more about it.

TASK - option 2

For the next part of today, you have a choice on what you want to do.

The first option, is to start designing your own cipher with a partner.

I'll talk to you a little about the design of a custom cipher here.

TASK - option 3

The other option for today's remaining time is to try to crack one of the following cryptograms.

The left one is a cipher that was first introduced to me when I was around y'alls age. The one on the right is a cipher of my own. Watching the video above may be beneficial. You can also get a paper copy of these two cryptograms.

HINT: These are both mono-alphabetic substitution ciphers.