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I've seen many claims that the blockchain can be used to provide traceability for various goods but I don't get it. For one thing this isn't trustless, the blo

by simias 9y ago

I've seen many claims that the blockchain can be used to provide traceability for various goods but I don't get it. For one thing this isn't trustless, the blockchain doesn't know what a diamond is so if a person entering a new diamond to the blockchain "database" decides to lie there's no way to prevent it "trustlessly". How do you prevent the same diamond to be entered twice in the chain? How do you prevent somebody from entering a diamond that doesn't exist in the chain? How do you make sure that some physical diamond you have in your hands matches an entry in the blockchain (and one only)? The ledger is immutable but diamonds aren't, what if a diamond is recut and the blockchain entry is not updated to match? What if I decide to "launder" some blood diamond by adding a transaction on the blockchain saying that it was destroyed, followed by a brand new clean entry pretending that I've just mined a new one? In the end you'd have to trust some sort of authority to put the diamonds on the chain honestly. So if you have decided to trust some authority, what do you need the blockchain for? Just have the De Beers cartel digitally sign a certificate for each diamond like an HTTPS certificate authority and bundle it with the stone. Exactly the same trust model and you don't have the overhead of the blockchain. Is there a use case that I'm missing or is it just yet an other occurrence of "let's say we do blockchain stuff and people will throw money at us"?

thisisit 9y ago
You are correct. Humans will be the weakest link in this security link, specially at the origin. Bitcoin etc solve this by using PoW. But here there can be issue if there is a malicious first entry That said, a case might be made for a traceable and immutable book which shows the movement of each diamond. But that might run into privacy issues. This can be solved by using a private blockchain but then again it goes back to trusting someone who has the blockchain with them.
- tomwalker 9y ago
  Completely agree. It seems to be the application of the current "trendy tech" to industry.
- simias 9y ago
  I agree with you but I want to point out that "a traceable and immutable book" is perfectly achievable without blockchain. Just have De Beers (or the authority of your choice) publish their signed "immutable" ledger publicly at regular intervals. Anybody can mirror it (like the "nodes" of bitcoin mirror the blockchain). If the authority decides to cheat and rewrite history (for instance to change the origin of a diamond) any of the 3rd party mirrors can detect the conflict and blow the whistle.
  - unboxed_type 9y ago
    Interesting point, thanks for sharing. But, anyway: What incentives do those mirroring nodes have to store regular data blobs and process requests from clients? Who will decide the privilege to be such a 'mirroring node'. The origin can run several such 'mirroring nodes' and rewrite history on all (some of) them: how would you know who is giving you the truth in case of conflicting information? I bet if you solve those questions, you will be simulating a blockchain system. Do you agree?
awefawefuiweuf 9y ago
correct
cabalamat 9y ago
> what do you need the blockchain for marketing bullshit > is it just yet an other occurrence of "let's say we do blockchain stuff and people will throw money at us"? Probably. Has their share price gone up yet? :-)
tabs_masterrace 9y ago
Maybe they want to do DiamondCoin, a crypto currency backed by diamonds, could be neat.
certcomm 9y ago
While not completely familiar with the technology that DeBeer's is using, I can comment on the general advantages of blockchain for Chain-of-custody. I am more familiar with pharmaceutical and food safety applications and so will comment on those. Firstly, with chain-of-custody one is tracking something external to the blockchain, so there is no getting around the fact that one needs to place some trust in the entities writing to the blockchain. The better way to think about it is that the blockchain allows you to trust "who" wrote to it and "what" they wrote, not whether what they wrote was an accurate reflection of the real world or not. (The real-virtual mapping problem) In the pharma industry for example you have hundreds of manufacturers and thousands of wholesalers and tens of thousands of pharmacies, thousands of carriers, thousands of re-packers, thousands of customs brokers, hundreds of freight forwarders and 3PLs etc. Furthermore, unlike Diamonds, it is not a simple linear flow of serialized items. Many items are actually lot-tracked and not serial-tracked. So, now you have the notion of splitting of lots and blending and combining of lots. Additionally items will go back and forth between distributors. Additionally, you have IOT readings along the entire provenance history like temperature, humidity, location etc. When an entity receives a serial or lot tracked item they can trace its provenance on the blockchain and decide whether and to what degree they want to trust whether what the previous entities wrote to the blockchain needed to be second guessed. Often when receiving, entities will perform some sort of QA. The degree of QA will be dictated by who, what, when and where the item went through in its entire journey. If they have high trust in the entities in the chain of custody they may only do partial check (eg. check for no broken seals), but if they don't trust the entities in the chain they may do a full assay of a sample or they may take the middle ground and do a quick spectrophotometry analysis. With any of these results they can write their certification to the blockchain so that subsequent entities may not have to re-certify if they trust this intermediate entity. So, one way to think about this is that chain-of-custody is not all or nothing, but rather based on degrees of trust. Also every participant views the situation differently based on whom they trust. Now back to the original question of whether this could be done with a central database instead of blockchain. The answer is "of course", but now even the who and the what is potentially suspect IN ADDITION to the virtual-physical mapping problem. Blockchain-based chain-of-custody solutions allows one to design a system focused only on mitigating the real-virtual mapping problem.
bb88 9y ago
So let's say we etch a QR code into each diamond which is only visible with a microscope. This is not unfeasible. In fact "Polar Bear" diamonds carried an etching of a polar bear. [1] So once you have the etching of a QR code then it makes sense for a blockchain, because then it makes determining the provenance for a diamond easier. And you could track stolen diamonds much, much easier. Though, I would be disappointed if DeBeer's only allowed it for their diamonds only. [1] https://www.theglobeandmail.com/news/national/diamonds-mined-in-nwt-to-carry-tiny-polar-bear-symbol/article25466673/ https://www.theglobeandmail.com/news/national/diamonds-mined...

by simias 9y ago

thisisit 9y ago

You are correct. Humans will be the weakest link in this security link, specially at the origin. Bitcoin etc solve this by using PoW. But here there can be issue if there is a malicious first entry That said, a case might be made for a traceable and immutable book which shows the movement of each diamond. But that might run into privacy issues. This can be solved by using a private blockchain but then again it goes back to trusting someone who has the blockchain with them.

tomwalker 9y ago
Completely agree. It seems to be the application of the current "trendy tech" to industry.
simias 9y ago
I agree with you but I want to point out that "a traceable and immutable book" is perfectly achievable without blockchain. Just have De Beers (or the authority of your choice) publish their signed "immutable" ledger publicly at regular intervals. Anybody can mirror it (like the "nodes" of bitcoin mirror the blockchain). If the authority decides to cheat and rewrite history (for instance to change the origin of a diamond) any of the 3rd party mirrors can detect the conflict and blow the whistle.
- unboxed_type 9y ago
  Interesting point, thanks for sharing. But, anyway: What incentives do those mirroring nodes have to store regular data blobs and process requests from clients? Who will decide the privilege to be such a 'mirroring node'. The origin can run several such 'mirroring nodes' and rewrite history on all (some of) them: how would you know who is giving you the truth in case of conflicting information? I bet if you solve those questions, you will be simulating a blockchain system. Do you agree?

awefawefuiweuf 9y ago

correct

cabalamat 9y ago

> what do you need the blockchain for marketing bullshit > is it just yet an other occurrence of "let's say we do blockchain stuff and people will throw money at us"? Probably. Has their share price gone up yet? :-)

tabs_masterrace 9y ago

Maybe they want to do DiamondCoin, a crypto currency backed by diamonds, could be neat.

certcomm 9y ago

While not completely familiar with the technology that DeBeer's is using, I can comment on the general advantages of blockchain for Chain-of-custody. I am more familiar with pharmaceutical and food safety applications and so will comment on those. Firstly, with chain-of-custody one is tracking something external to the blockchain, so there is no getting around the fact that one needs to place some trust in the entities writing to the blockchain. The better way to think about it is that the blockchain allows you to trust "who" wrote to it and "what" they wrote, not whether what they wrote was an accurate reflection of the real world or not. (The real-virtual mapping problem) In the pharma industry for example you have hundreds of manufacturers and thousands of wholesalers and tens of thousands of pharmacies, thousands of carriers, thousands of re-packers, thousands of customs brokers, hundreds of freight forwarders and 3PLs etc. Furthermore, unlike Diamonds, it is not a simple linear flow of serialized items. Many items are actually lot-tracked and not serial-tracked. So, now you have the notion of splitting of lots and blending and combining of lots. Additionally items will go back and forth between distributors. Additionally, you have IOT readings along the entire provenance history like temperature, humidity, location etc. When an entity receives a serial or lot tracked item they can trace its provenance on the blockchain and decide whether and to what degree they want to trust whether what the previous entities wrote to the blockchain needed to be second guessed. Often when receiving, entities will perform some sort of QA. The degree of QA will be dictated by who, what, when and where the item went through in its entire journey. If they have high trust in the entities in the chain of custody they may only do partial check (eg. check for no broken seals), but if they don't trust the entities in the chain they may do a full assay of a sample or they may take the middle ground and do a quick spectrophotometry analysis. With any of these results they can write their certification to the blockchain so that subsequent entities may not have to re-certify if they trust this intermediate entity. So, one way to think about this is that chain-of-custody is not all or nothing, but rather based on degrees of trust. Also every participant views the situation differently based on whom they trust. Now back to the original question of whether this could be done with a central database instead of blockchain. The answer is "of course", but now even the who and the what is potentially suspect IN ADDITION to the virtual-physical mapping problem. Blockchain-based chain-of-custody solutions allows one to design a system focused only on mitigating the real-virtual mapping problem.

bb88 9y ago

So let's say we etch a QR code into each diamond which is only visible with a microscope. This is not unfeasible. In fact "Polar Bear" diamonds carried an etching of a polar bear. [1] So once you have the etching of a QR code then it makes sense for a blockchain, because then it makes determining the provenance for a diamond easier. And you could track stolen diamonds much, much easier. Though, I would be disappointed if DeBeer's only allowed it for their diamonds only. [1] https://www.theglobeandmail.com/news/national/diamonds-mined-in-nwt-to-carry-tiny-polar-bear-symbol/article25466673/ https://www.theglobeandmail.com/news/national/diamonds-mined...