How does encryption protect data at rest?

Encryption protects data at rest by transforming it into a format that cannot be easily understood without the appropriate decryption key. This process involves using algorithms to convert the original data into an encoded version, effectively rendering it unreadable to unauthorized users. Consequently, even if an attacker gains access to the physical storage media where the data is kept, they would only find a series of scrambled characters or numbers instead of the original, meaningful information.

The significance of using a decryption key is that only individuals or systems with the correct key can revert the encoded data back to its original state, ensuring confidentiality and protecting sensitive information from unauthorized access. This is particularly important for safeguarding personal data, financial records, and proprietary company information stored on servers, databases, or other forms of data storage.

The other options are not effective for data protection in the same way encryption is. Making data accessible to all users undermines confidentiality, redundant backups do not inherently protect against unauthorized access, and increasing data compression rates does not secure the data's integrity or confidentiality.