nonrewritable

Nonrewritable storage refers to media or data repositories in which data, once written, cannot be modified or erased by design. The term is commonly used for write-once, read-many (WORM) storage, which enforces immutability to protect records from alteration after creation. In practice, nonrewritable systems ensure that a digital object remains in its original form for a defined retention period.

Mechanisms to achieve nonrewritability include physical write-once media such as CD-R, DVD-R, and WORM-capable optical media, as well as magnetic or solid-state systems configured with write-protect features or append-only modes. Logical approaches include retention policies and cryptographic protections that prevent overwriting and support tamper evidence. In some platforms, attempts to modify an existing object are blocked, and new versions can only be added as separate entries or under explicit governance.

Typical uses are regulatory compliance, legal discovery, financial recordkeeping, medical archives, and archival of long-term logs. Benefits include data integrity, traceability, and defensibility in audits, while reducing the risk of accidental or intentional data alteration. Limitations include the need for planned data migration as media ages or technology evolves, potential inefficiencies for workloads requiring frequent updates, and the necessity of strong access controls and integrity verification to prevent bypass.

In cloud and modern storage environments, immutability features such as retention periods, governance or compliance modes, and versioning can provide nonrewritable behavior at scale, without relying solely on physical media. The concept emphasizes protecting the authenticity of records over time.