Data redaction is the removal or masking of sensitive information before a document, image, or dataset is shared. It can conceal details such as names, account numbers, medical information, or device identifiers. Effective redaction permanently removes the underlying data; placing a visual box over text may leave it recoverable from the file.
Redaction helps reduce privacy, fraud, and identity-theft risks when organizations publish records or disclose evidence. In cyber incidents, attackers may release samples with fields masked, while defenders must verify the material and assess what sensitive information remains visible. Redaction can limit exposure, but it does not prove that a breach occurred or establish its full scope.