Your China-based production partner sends a master. The downloaded video plays, but its checksum differs from the delivery manifest. Should the team request another transfer, or accept the explanation that the review platform processed the file?
Start with the object you agreed to receive. An unchanged copy and an approved derivative are different deliverables. File integrity checks help distinguish them, but do not approve the edit, its captions or its rights.
Agree what must remain unchanged
The Digital Preservation Coalition's Fixity and checksums guidance covers checking files on receipt, during storage and on retrieval. It also explains that intentional format migration requires a new checksum baseline. We checked the page on October 31, 2026; no publication date was established from it.
Jefferson Bailey's Protect Your Data: File Fixity and Data Integrity, published by the Library of Congress's The Signal on April 7, 2014, describes comparing received files with pre-transfer checksums, or establishing a baseline on taking custody when none exists. We re-read it on October 31. These are established preservation practices, not a newly launched industry feature.
ONCE's proposed handoff rule is to identify the file, algorithm and trusted reference before interpreting a mismatch. A platform-generated preview should not be expected to match the whole-file checksum of its source master. A locally calculated value without a sending reference cannot retrospectively verify the earlier transfer.
Four states for a practical handoff
| State | Next action | What remains unproven |
|---|---|---|
| Same file and algorithm; received value matches the trusted sending reference | Record the integrity check and continue content acceptance | Caption accuracy, approval and rights |
| An unchanged copy was required, but values differ | Preserve the discrepancy, investigate and retransfer from a verified good copy if needed | The cause or responsible party |
| An authorized transcode or other intentional change occurred | Review the derivative and establish its own baseline | Byte-for-byte identity with the master |
| No trusted sending reference exists | Record the earlier transfer as unverified; review the current file and establish a future baseline | Its unchanged history before receipt |
If algorithms differ, first compare the same file using the same algorithm. Also check that the manifest identifies the intended object. Matching filenames do not establish identity if someone has replaced a file or selected another directory.
Do not make an unexplained difference disappear
In a fictional handoff, an approved English master is meant to arrive unchanged. Its received checksum does not match the manifest. Check the file identity, calculation method, transfer route and any intended processing before deciding whether to download again, request a new transfer or investigate a stored copy.
Replacing the old manifest with the newly calculated value does not explain the discrepancy. It simply creates a different starting point. If there is an urgent business need to use the file, an appropriate owner must review the actual asset and intended use while retaining the unresolved status. Do not report that the integrity check passed.
Give deliberate derivatives their own identity
Now imagine the brand specifically ordered a smaller preview from a high-quality master. If the file's bytes change, its checksum can differ. Trying to force that value to match the source misses the purpose of the derivative. Review its picture, audio and intended use, then record its parent master, processing and approval.
A metadata edit written inside a file can also change its whole-file checksum without an obvious picture change. Conversely, moving or renaming a file without changing its contents is not a reason to claim that a new picture version was made. Describe the operation that actually occurred.
Detection is not recovery
The DPC guidance notes that a checksum does not locate the changed part of a file, and that replacing a damaged copy requires a known good copy. Purchasing periodic checks is therefore different from purchasing backup capacity, recovery or project reconstruction. A digest alone cannot restore missing footage.
A match supports consistency with a trusted reference under the chosen method; it does not establish authorship, rights or correct content. An approved-reference error can be copied perfectly. Continue with the agreed checks of specifications, picture, sound, captions and permitted use.
Specify what the archive service actually does
For the next handoff, agree which files must remain unchanged, who generates the sending manifest, who checks receipt, who maintains the reference and who handles exceptions. For retention, add the checking scope and frequency, term, location of good copies and recovery responsibility. Choose intervals for the storage environment, usage and risk; this article sets no universal schedule.
Ask a video production partner to separate capacity, checking, reporting and recovery in the scope. More storage does not automatically mean ongoing checks, and a check log does not guarantee an available recovery copy. This method assumes no standard market price or saving.
For ONCE's long-term content services, the useful record connects an approved version with its transfers, checks and subsequent derivatives. That is a proposed service capability, not a demonstrated client result. When a mismatch arrives, first ask whether the two objects were supposed to be the same unchanged file. Then decide between retransferring and documenting a new version.
Sources checked October 31, 2026. The four-state workflow and handoff scenarios are ONCE editorial analysis. No client files, storage system or recovery capability was tested. The original AI cover is conceptual.
