So, again what trust issues does blockchain solve?

To ensure we are not talking about completely abstract things let's take a real life example. Here's an issue:

https://www.reuters.com/article/us-welspun-india-walmart-idU...

Wal-Mart Stores Inc on Friday said it will stop selling Egyptian cotton sheets made by Welspun India after the Indian manufacturer was unable to assure them the products were authentic.

How does blockchain help?

These are all timestamped, impossible to alter, and would require an elaborate planned fraud between a number of parties to fake.

How would you do this without blockchain? with a trusted 3rd party. Who can you trust when you are involving the russian govt, chinese govt, and US govt, and EU, and corrupt italian public servants? none of those groups trust any of the other parties completely.

Points 1 and two aren't solved in any way, as the buyer has to trust the producer to not lie when making the entry. In other words, the trust problem here occurs before entry into the database.

Point 4 is already solved with by a multitude of companies selling those temperature-sensible stickers (and adding/removing the stickers is the same vulnerability as adding/removing the iot device).

BTW, with a blockchain solution, these are not at all "impossible to alter". That would only be true for a blockchain that is actually decentralized and heavily mined. That implies a blockchain with a multitude of products using the same chain (e.g. not just an OliveOilChain), but then we approach the scaling border very fast, making a blockchain unusable for this use case.

The blockchain will show in time that X producer sells X amount of extra virgin, virgin, and regular olive oil. This will make it difficult for a small single origin producer claiming that ALL of their output is extra virgin. It would also make it difficult for a small producer to rebrand large volumes of some other olive oil as their own.

As for the temp-sensing stickers - add GPS, encryption and transmitting functions and you can add some cool features to temp sensing stickers.

Finally- there isn't THAT much data involved here for the $$ involved, you could do it on the ethereum blockchain or even the litecoin chain. There are quite a number of ultrasecure blockchains at this point.

An excellent point.

I wonder if a market will emerge from the need to secure (and thus mine) these private blockchains. IE, perhaps Walmart could secure its logistical blockchain by compensating miners in "WalmartCoin", which is redeemable at the store.

Couple of questions though -

How would the IOT device in the shipping load know what temperature the olive oil has been? Please don't say the IOT device can be placed in farms because we are currently talking about a logistics systems.

And even if the IOT was placed in the farms - how would anyone verify if the IOT ie the source of data was hacked. Maybe just enough to show that the farm is producing 10% more extra virgin oil?

How would the blockchain entries be managed? Because remember a block is added via majority rules - PoW or PoS. So, in case of olive oil manufacturing - who would verify if the IOT entry is correct?

What happens if the IOT is not tampered and just malfunctions giving incorrect data?

This is where the human element comes into play, and something the blockchain cannot secure.

However, for the 0.01% of use cases where you can't trust the government (money printing) or where the stakes are too high to rely on the security of a trusted 3rd party, blockchain is great.

The article states this initiative "helps reduce waste, better manage contamination cases and improve transparency"

This is how I envision this system working. I think the fact this is produce and not normal inventory is key.

Produce is produced by farmers, transported by shipping companies, stored in warehouses, and eventually ends up on a shelf after a long chain of custody.

Reducing waste and contamination sounds like a tracking system. So every food item gets an ID and as it moves through the system it gets logged with time, location, and so on. Pretty standard, and yes, totally doable with a database.

But this project also helps to improve transparency. Transparency to who?

The previous actors in our example. The farmer, the shipper, storage, maybe inspectors.

They have no inherit reason to trust each other. The last shipping company will blame the warehouse for the moldy food. The warehouse will blame the farmer. The inspectors said they approved of it but obviously its gone bad.

Maybe the 6 days to track this produce before wasn't really in tracking it, but dealing with the human element of the chain of custody. Two minutes to pull up a verified log of events.

It has copy on its site stating it "allows multiple different parties to securely interact with the same universal source of truth."

I think the fact that IBM is running this, and not Walmart, is actually a plus. The suppliers don't have to worry about Walmart itself making data changes. Of course the details will vary, but I highly doubt the platform allows the account owner to unilaterally make changes to this source of truth. It's totally against the point of the project.

But all of that would be vastly simpler with a central trusted third party.

At the end the job is technically quite simple. Maintaining a semi-public database. It's pretty black or white.

Equifax was a trusted 3rd party with no skin in the game.

Facebook was too (at least it was trusted by the west, the chinese never trusted it).

As Walmart is the sole owner of the database anyway, nothing is gained by using a blockchain.

Walmart is making this change to improve something. They obviously already have a database somewhere with suppliers and shipments and to think they don't is just crazy.

Sure, contract law. But why when there is a technical solution? If there is a dispute that then has to be settled in the courts with your solution that costs more money and time. The 6 days to 2 minutes might end up way longer after amortizing time spent dealing with trails and compliance and ensuring suppliers are doing things right.

I think I don't see any of the multiple trust relations solved in this case.

Walmart still can't trust the producer to itemize the physical product correctly.

The producer still can't trust Walmart to not change the item already in the database (see mining discussion above).

What trust relation do you have in mind, that is solved with this blockchain implementation, and that wouldn't be solved with a ordinary database with signed entries?

This seems entirely centralized, and thus a very poor use case for a blockchain.

> Yiannas said blockchain was able to cut the time it took to track produce to two seconds from six days.

With no more detail I can't even start to think how a Blockchain DB makes any difference?

Did you not read the title of the post, or the title of the linked article, or the article itself?

https://www.ibm.com/blockchain/platform/

https://www.hyperledger.org/about

Its funny how this applies to almost all blockchain applications.

Do you believe that all implementations of a ledger with distributed access are equivalent?

Private blockchains don't have to have nodes mining 24/7.

They can wait until the mempool is at a certain transaction count then new blocks could be added. Or they could mine 1 transaction blocks as they come in. It doesn't have to work like bitcoin or cryptocurrency in general.

Or maybe its batch-like and mining happens once a day at midnight.

There is no reward for adding a block so there is no race. All miners are known and block minting can be pre-planned.

Lets assume 10 suppliers each add 10 new 'produce transactions' on some day. It also occurs during work hours, so maybe between 9-5 there is 100 new transactions.

The miners are all known nodes, in fact, only 10 of them if we assume each supplier gets one.

Once the 100 transactions are minted into new blocks and the day ends...

What exactly are the miners supposed to mine into blocks? There are no transactions. Nothing to add.

The mining is completely worthless in the scenario you described. Imagine either a rogue producer or Walmart having an interest in changing the database. In your scenario of 10 mining boxes the adversary would just have to buy 5 additional boxes and would have complete control over the blockchain.

There is a video that offers a high level view of farm to fork (agriculture products to consumers) using the block chain ideas in Hyperledger Fabric.

From Nigel Gopie, an IBM Food Trust speaker, says "The permissioned blockchains we rely upon (hyperledger fabric) don’t use don't use proof-of-work or "mining" — unlike some other Blockchains like bitcoin — which is what consumes huge amounts of energy. " (from a tweet conversation after a presentation he gave in Denver April 2018: https://twitter.com/analyticsbytes/status/984140954834632704)

Walmart Inc. is getting suppliers to put food on the [database] to help reduce waste, better manage contamination cases and improve transparency.

Yiannas said [database] was able to cut the time it took to track produce to two seconds from six days.

Phew! Blockchain is NOT a database, you don't put something ON blockchain. Blockchain is meant to track changes of data, not store the data. The size of the entire Bitcoin Blockchain over the last 9+ years is 194.86GB [0] i.e. it can be stored on your local hard drive. Therefore, you can't put "food on blockchain".

[0] https://bitinfocharts.com

Amazon to stop delivering goods by walking to people's front doors, now delivering through the radio waves!

That's a billion dollar ICO right there.