Write protection
Write protection is a security mechanism in computing that prevents the writing, modification, or erasure of data on storage devices, ensuring data integrity and protecting against accidental or unauthorized alterations.[1] This feature is implemented through hardware or software methods to render storage media read-only while allowing data to be read and accessed.[2] Hardware write protection typically involves physical components, such as toggle switches on USB flash drives or SD cards, which mechanically block write operations when activated.[1] In contrast, software write protection uses operating system controls, file permissions, or specialized commands—for example, thediskpart utility in Windows or [hdparm](/page/Hdparm) in Linux—to enforce read-only status on drives or partitions.[2]
Key mechanisms include hardware write blockers, which intercept and nullify write commands at the interface level (e.g., via ATA, SATA, or SCSI protocols), and software-based filters that modify system interrupts or driver behaviors to prevent data changes.[3] These approaches are applied to various media, including hard disk drives, solid-state drives, optical discs like CDs and DVDs (which can be finalized to prevent further writing), and removable storage like floppy disks with protective tabs.[2]
Write protection plays a critical role in data security by mitigating risks from malware, human error, or deliberate tampering, and it is especially vital in computer forensics, where hardware and software blockers ensure evidence preservation during acquisition without altering original data, maintaining chain-of-custody integrity for legal proceedings.[3] Benefits extend to compliance with standards in industries handling sensitive information, such as healthcare and finance, where unaltered records are essential.[1]