To this date, the IOTA network truncates all stored transactions after a snapshot, so that we basically only have an image of addresses with funds.
Now lets assume following scenario: Company
A stores their car's system metrics such as mileage and service count on the Tangle with a (right now non existent) standardized schema. This means that zero value transactions are issued by the car or a central node of the company, which include the data as the payload inside the transactions. Lets assume a buyer
B wants to verify, that in fact that second hand car of Company
A he/she buys, really has the mileage written on the tag of the seller. Now buyer
B could verify that in fact the mileage is correct by querying the IOTA ledger for transaction of the particular car. I imagine that this would work by scanning a QR code from the car's windshield where a service provider (company
S) provides an app which lists the last X amount of transaction of the car, pulled from the Tangle and displays them in a pretty way.
There are several questions which arise from this scenario:
- If a snapshot happens, the transactions of the car containing the relevant data is lost. There's no incentive for anybody but the car company
Ato permanently store the transactions of the cars they manufactured after a snapshot. Obviously we would have X amount of other companies storing data on the ledger but really nobody but the companies themselves would really care about the their own produced data. Now the data is only held by company
A, transferred via company
S: how would you verify that the data wasn't tempered with after it got from the companies permanodes to your smartphone's display? Your only source of the data is company
Abecause nobody else holds it, so you can't check it against other sources. Even if the payload of the transaction held a signing key instead of the actual data, there's no way to ensure that the signing key wasn't forged at a later time or during transmission of the data from company
- With the Tangle you can only really verify that a particular transaction was issued by a specific party but the data inside the payload must not really be true at all: while this works for the value transfer inside the network by using the native IOTA token, it doesn't when the data is generated somewhere else in the first place. In that sense, the data of the mileage could be faked by the car issuing the transaction in the first place. How does someone verify data truthfulness if the data is generated by non-standardized proprietary sensors before they even hit the Tangle in the first place?
For question 1 I could imagine that a standardized permanode of all car manufactures could be used, where everyone submits their metrics data and it is stored indefinitely and is legitimized by all governments using the specific technology which allows to query that database. However, what would be the incentive to use the Tangle for this particular application in the first place, when a simple standardized and approved API by multiple governments would be much faster and optimization would be easier to implement by the working group who created it?