A determination can be made that an item of confidential information has been removed from a record. A determination can be made that the record has the item of confidential information. The item of confidential information can be represented by an original value. A replacement value can be calculated. The replacement value can be a value of a transformation function applied to the original value. The replacement value can be testable for an existence of a digital signature, the digital signature to be derived from the replacement value. The record, in which the original value has been replaced by the replacement value can be used for a test. The test can be of a characteristic of an application. An ability to derive the digital signature from the replacement value can be an indication that the item of confidential information has been removed from the field.