Some of the members of the Slimcoin Owners Club are exploring the notion of inscribing
TrustyURIs in the slot offered by OP_RETURN data. There are similar associated issues to be addressed, such as limiting tx search to specific addresses, etc.
I just yesterday got the time to re-read the Trusty URI paper (I had already looked at it, but very superficial). I just wanted to make sure I understand your idea to create "assets" based on signed RDF graphs. So here's my understanding of it:
1) Let's say Alice is wanting to issue an asset to crowdfund her startup. She creates the following RDF graph (in simplified Triples, as example, "ccy" for the Cryptocurrency Ontology and "sla" as a prefix for "SlimAssets"):
ccy:SAliceSAddressxxx sla:issue (BlankNode)
(BlankNode) sla:id sla:AlicesAsset
(BlankNode) sla:quantity 1000
(For those that do not know RDF: Blank nodes often are used if you want to relate a subject-predicate combination - e.g. Alice's "issuing" of the asset - to several predicate-object combinations -
N-ary relations - without "splitting" the triple. In this case, the ID and the quantity are related to the "issuing act".)
2) She signs the graph and then includes a self-reference for the trusty URI.
3) She inscribes the Trusty URI into the blockchain.
Now Bob wants to buy 100 of these assets. He comes to an agreement with Alice (the payment process from Bob to Alice here is not important, that would be a separate issue). When he pays to Alice, she creates the following graph:
ccy:SAliceSAddressxxx sla:transfer (BlankNode)
(BlankNode) sla:quantity 100
(BlankNode) sla:destination ccy:SBobSAddressxxx
again, signing it with SAlliceSAddressxxx and creating the trusty URI.
She can now inscribe the graph in the blockchain, and so the asset transfer would have taken place.
Is this approximately correct?
(It's possible that it's necessary to include the trusty URI to the issuance graph in the subsequent transactions, e.g. if Bob is selling his assets. Maybe the Trusty URI for the issuance could even be the asset ID?)
In this model, not all data is inscribed in the blockchain, only the trusty URI, while the graph itself is recorded off-chain. What are the security implications? In theory, Alice could try to hack Bob's computer, delete his record of the graph, and then say that she never transferred him the assets, and that her trusty URI is referring to another transaction. Now this reminds me a bit of the security model of the Lightning Network: in LN, also, if your node isn't aware of the state of your channels, then your counterparty can scam you.
An interesting issue is that with this model one could create enormous asset transactions, serving 1000s of people with assets (e.g. for an "airdrop") but the blockchain entry would continue to be small. It could be even possible to combine this model with Lightning-like HTLCs, what would create a kind of "sidechain" for each asset, so asset transfers wouldn't have to be recorded at the main chain at all.
