What does encryption do to data?

Encryption transforms data into a format that cannot be easily understood without a decryption key. This process involves applying specific algorithms to the original data (often referred to as plaintext), which changes its representation into an encoded version (called ciphertext). The purpose of encryption is to protect sensitive information from unauthorized access; only individuals who have the correct decryption key can revert the ciphertext back to its original, understandable format. This ensures that even if the encrypted data is intercepted or accessed by an unauthorized party, it remains secure and unreadable.

The other options do not accurately describe the primary function of encryption. Compression refers to reducing the size of data to save storage space, which is a different process. Backing up data to cloud storage involves storing copies of data for recovery but does not alter its format. Lastly, increasing running speed is unrelated to encryption, as encrypting data typically adds processing overhead that could decrease speed rather than increase it.