The correct option is C. encryption. Explanation of the Correct Answer Encryption is the process of converting data into a coded format that can only be read by someone who has the appropriate key or password to decode it. This is done to protect sensitive information from unauthorized access. When data is encrypted, it becomes unreadable to anyone who does not have the decryption key, ensuring confidentiality and security. How Encryption Works:

1. Plaintext: This is the original data that is readable and understandable.
2. Encryption Algorithm: This is a mathematical procedure used to transform plaintext into ciphertext. Common algorithms include AES (Advanced Encryption Standard), RSA (Rivest-Shamir-Adleman), and DES (Data Encryption Standard).
3. Key: This is a piece of information used by the encryption algorithm to perform the transformation. The key must be kept secret to maintain the security of the encrypted data.
4. Ciphertext: This is the result of the encryption process. It appears as a random string of characters and is not understandable without decryption.

For example, if we take the word "HELLO" and apply a simple encryption algorithm with a key, it might be transformed into "KHOOR". Without the key, someone who intercepts "KHOOR" cannot easily determine that it corresponds to "HELLO". Why the Other Options Are Incorrect

• A. Authentication: This refers to the process of verifying the identity of a user or system. It ensures that the entity trying to access a system is who they claim to be. While authentication is crucial for security, it does not involve translating data into a secret code.
• B. Authorisation: This is the process of determining whether a user has permission to access certain resources or perform specific actions. It comes after authentication and is about granting or denying access based on permissions. Like authentication, it does not involve encoding data.
• D. Piracy: This term refers to the unauthorized use or distribution of someone else's intellectual property, such as software, music, or movies. Piracy is illegal and unethical but is not related to the process of encoding or securing data.

Summary of Key Points

• Encryption is the process of converting readable data (plaintext) into an unreadable format (ciphertext) to protect it from unauthorized access.
• It uses algorithms and keys to ensure that only authorized users can decrypt and access the original data.
• Authentication and authorisation are processes related to verifying identity and granting access, respectively, but do not involve data encoding.
• Piracy is about the illegal use of intellectual property and is unrelated to the concept of encryption.

Revision Summary

• Encryption protects data by converting it into a secret code (ciphertext).
• It requires an algorithm and a key for both encryption and decryption.
• Authentication verifies identity; authorisation grants access; neither involves encoding data.
• Piracy is illegal use of intellectual property, not related to data security.