Intro
Encryption Algorithms
What is encryption?
Encryption is the scrambling of data so that only the intended recipient of data can decode and read it. In the starter you successfully decrypted anagrams to read the hidden word. This is a form (albeit very weak!!!) of encryption!
What is it used for?
Encryption is used for a wide variety of purposes, including:
- Stopping unauthorised people accessing your school reocrds
- Protecting internet shopping transactions
- Securing online banking transactions
- Keeping your social media messages private
Caesar
Caesar Shift Cipher
The Caesar Shift is named after Julius Caesar, who used it to encrypt all messages of military significant. It is a form of substitution cipher, where letters were ‘shifted’ along the alphabet by a certain number of letters. Caesar used a shift of 3 in all his ciphers.
3 Shift example
Using the 3 Shift example above you can encrypt a message…
Original: IHATESPROUTS
Coded: LKDWHVSURXWV
As you can see by the table above, letter G would be changed to J, M to P. To decrypt the message, you simply reverse the process.
Encryption Strength
- In Caesar’s lifetime there were no known records of his cipher being broken by the enemy, although this is likely because often the enemy would be illiterate.
- In practice this algorithm is very easy to break, either manually, or with the aid of a computer and is extremely insecure.