Encryption
Encryption is a method of encoding data in a way that only authorised users can access it.
The basic idea is that we take our original data, called plaintext, and we use
a maths function, called an encryption algorithm, to transform that plaintext
into a new form, called ciphertext, which is unreadable to anyone who doesn’t
have the key to decrypt it.
Sometimes we call this encryption algorithm the cipher.
Importantly, only the intended recipient of the data should have the key to decrypt it.
Why use encryption?
When we send data over the internet, anybody along the route of the ‘packet’ of data can read its contents.
It’s often important that we send data privately - things like passwords, card details, messages, etc. - so that only the intended person is able to read it!
flashcards
| Question | Answer |
|---|---|
| Encryption | Encryption is a method of encoding data so that only authorised users can access it. |
| What is plaintext? | Plaintext is the original, unencrypted data. |
| What is ciphertext? | Ciphertext is the unreadable form of data produced by encryption. |
| What is an encryption algorithm / cipher? | An encryption algorithm, or cipher, is a mathematical function that transforms plaintext into ciphertext. |
| Who should have the decryption key? | Only the intended recipient of the data should have the key to decrypt it. |
| Why is encryption important for internet communication? | When data is sent over the internet, anyone along the route can read its packet contents; encryption ensures private data like passwords and card details are only readable by the intended person. |