What is a common method used to protect data at rest from being read by unauthorized users?*SSL/TLSTwo-factor authenticationEncryptionFirewalls

The common method used to protect data at rest from being read by unauthorized users is Encryption.

Here's a step-by-step explanation:

1. Data at rest refers to data that is not actively moving from device to device or network to network such as data stored on a hard drive, laptop, flash drive, or archived/stored in some other way.

2. Data Protection at rest aims to secure inactive data stored on any device or network. This means the data is stored in a non-volatile form like on your hard disk drive, SSD or storage tapes.

3. Encryption is a method where information is encoded and can only be accessed or decrypted by a user with the correct encryption key. Encrypted data, also known as ciphertext, appears scrambled or unreadable to a person or entity accessing without permission.

4. Encryption is used to protect sensitive and important data, but it can also be used to protect data at rest. When data is encrypted, even if the storage medium is stolen or accessed by someone else, they will not be able to read the data without the encryption key.

5. SSL/TLS, Two-factor authentication, and Firewalls are also methods to protect data, but they are typically used to protect data in transit (SSL/TLS), verify the identity of users (Two-factor authentication), or protect against unauthorized access (Firewalls).

So, to protect data at rest from being read by unauthorized users, encryption is commonly used.