Warborn BladesSerial Numbers vs SKUs
Serial Numbers vs SKUs: Item Identifiers That Survive Counterfeiting
A SKU says what it is. A serial says which one. Only one of those can carry proof.
Three kinds of number, doing three jobs
A SKU identifies a product line for your own stock control. Every unit of that model shares it, and it is meant to be shared.
A batch or lot code identifies a run — useful for recalls and quality tracing, useless for authentication, because thousands of units carry it.
A per-item serial identifies one physical object and no other. Only the third can carry provenance, because provenance is a claim about a particular thing rather than about a category.
Merchants routinely try to make a SKU do the third job. It cannot. Once one unit is photographed, every claim tied to that number is public.
Designing an identifier that resists attack
Do not use sequential numbers alone. A counterfeiter who buys two units learns the interval and can mint plausible identifiers between them. Sequence plus a check value derived from a secret is the minimum.
Make the space sparse. If valid identifiers are one in a million rather than one in ten, guessing becomes an activity the register can detect and rate-limit.
Do not encode meaning a rival can read. An identifier that reveals the factory, the production date or the batch is a source-shielding leak wearing a provenance costume.
Log every verification attempt, including failures. Failed lookups clustered in time are the clearest early signal of a counterfeit run being tested.
Marking the object, not just the paperwork
An identifier is only as good as its binding to the item. Laser etching, stamped marks, sewn labels and tamper-evident applications are all reasonable; a sticker that peels off intact is not.
Where the piece cannot be marked visibly without harming it — a blade's finish, for instance — mark a concealed surface and record where. A mark whose location is known only to the register and the maker is a second test.
Record the mark's photograph at issue. A high-resolution image of the actual mark on the actual item is remarkably hard to counterfeit, because the forger must match a specific object's wear rather than a font.
What this house built
Every piece of steel that leaves Warborn Blades carries a per-item mark, recorded before it ships, resolvable without asking us, and watched for duplicate presentation.
The Seal of Provenance is that machinery, and it is licensed to houses who want the same discipline over their own goods.
See the register that holds the marks
The Seal of ProvenanceAsked of the house
- Can I use my SKU as a serial number?
- No. A SKU is shared by every unit of a product line, so any claim tied to it becomes public the moment one unit is photographed. Authentication requires an identifier unique to a single physical item.
- Should serial numbers be sequential?
- Not on their own. Sequential numbers let anyone holding two units infer valid identifiers in between. Combine a sequence with a check value derived from a secret, and keep the valid space sparse so guessing is detectable.
- What is the difference between a batch code and a serial number?
- A batch or lot code identifies a production run and is shared by every unit in it, which makes it useful for recalls and useless for authentication. A serial number identifies one item and no other.
- How should a serial number be marked on a product?
- In a way that cannot be transferred to another unit — laser etching, stamping, sewn-in labels or tamper-evident application. A removable sticker authenticates the sticker. Photographing the actual mark at issue adds a second test that is hard to forge.
Have your own house read
Leave your storefront and we will read it against serial numbers vs skus ourselves and send you what we find, plainly, with the evidence attached. No charge for the first reading, and no obligation after it.
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