Course: An Introduction to Cryptography

Welcome to the thrilling world of cryptography! Cryptography is the exciting world of secret codes and encrypted messages. It’s like a puzzle that keeps your mind sharp and your information …

In this activity you learned about four kinds of ciphers (substitution, transposition, permutation and polygraphic ciphers) and you had a go at encrypting and decrypting data manually. This is normally …

In this video, Sam provides a summary of what you have learned about on this course. Reflect and share Choose one or two of the following questions to reflect on: …

Congratulations! You have come to the end of Activity 4. In this activity you learned about end-to-end encryption and where it is used. We also explored the idea of hash …

All of the simple ciphers that we have considered so far are not safe to use as a cipher in modern times. This is because it is too easy to …

Digital signatures are an important part of the internet. Digital signatures are primarily used to verify the authenticity and integrity of digital documents or messages.  A digital signature is a …

In the previous step you learned about what hashing and hash collisions are. In this step you will get some practical experience of hash functions. Hash generator Using the online …

Sometimes, we need to store data securely. For example, when you create an account on a website you normally set up a password so that you can log in. However, …

In this video Sam explains some sample solutions for the simple cipher task you tried in the last step. You’ll see an example of how to encrypt and decrypt using …

Now it’s your turn In this step, we have set out a number of exercises for you to do; decryptions and encryptions based on a Caesar cipher and a permutation …

What is a polygraphic cipher? A polygraphic cipher is a type of substitution cipher that operates on groups of characters rather than individual characters. In other words, instead of substituting …

End-to-end encryption (E2EE) is a type of encryption that is designed to protect the confidentiality and integrity of digital communications. It works by encrypting messages on the sender’s device and …

In the last activity we learned a little about a modern day cryptographic technique called RSA. We looked at the difference between public and private key cryptography. In this activity …

In this activity we have looked at some modern day cryptography. We have learned of two modern approaches: private key cryptography and public key cryptography. We looked at a specific …

What is a transposition cipher? Earlier in the activity, we saw the scytale cipher. This is an example of a transposition cipher. In this type of cipher, the characters in …