The diagram shows a simplified view of how data is transmitted securely between two computers using encryption. (a) Using the diagram, describe the process ...

(a) The process of encrypting and decrypting data (using the diagram) [4]

1. The sender's plain text (the original readable data) is passed into an encryption algorithm along with an encryption key. [1]
2. The algorithm transforms the plain text into cipher text, which is scrambled and unreadable to anyone who does not have the correct key. [1]
3. The cipher text is transmitted across the network to the receiver. Even if intercepted during transmission, the data appears as meaningless characters. [1]
4. The receiver passes the cipher text through a decryption algorithm along with the correct decryption key, which converts the cipher text back into the original plain text. [1]

(b) Why encryption is important for data transmitted over the internet [2]

Data transmitted over the internet passes through many intermediate devices and networks (routers, switches, ISP infrastructure), any of which could potentially be monitored by attackers. [1]

Encryption ensures that even if the data is intercepted at any point during transmission, it appears as meaningless cipher text that cannot be read or used without the correct decryption key. [1]

(c) One type of data that should always be encrypted [1]

Financial data such as bank account numbers, credit card details, and payment transactions should always be encrypted during transmission to prevent theft and fraud. [1]