Definition
Full disk encryption, often abbreviated as FDE, is a security measure that scrambles all data stored on a computer's hard drive or other storage media. This process renders the data unreadable to unauthorized individuals, even if they gain physical access to the device. FDE works by using cryptographic keys to encrypt and decrypt data on the fly as it is accessed or written. Implementing FDE is crucial for protecting sensitive information from theft or loss, ensuring compliance with data privacy regulations. For instance, a laptop with FDE that is stolen can prevent sensitive company data from being compromised. Unlike file level encryption which protects individual files, FDE secures the entire storage volume. This concept is frequently tested on cybersecurity certifications like CompTIA Security+ and CISSP.