If so a blockchain of its own is needless "bloat"; one could simply offer customers a range of costs of existing, expected to be secure chains on which to record a cryptographic proof, no need to store entire object, owner of object can retain actual object / 3D-file as long as they feel they need, holding also along with it algorithm / program that creates the algorithmic proof given the actual file.
Some customers might choose to have their proof written to bitcoin blockchain, others maybe even also to various other chains as redundancy.
-MarkM-
That's an arguable point, whether it is pointless to store. imho
In PoW miners are finding new blocks, but they store "nonce" one the blockchain (proof is part of the blockchain).
Every block represents a piece of value, as well as the user object in 3Dpass does.
Miners could have stored proof of work somewhere outside of the blockchain. Why didn't it work this way?