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Sorry, but your solution solves nothing. The transporter could take a picture of the odometer and tweak the image. Your solution is only as secure as the input

Sorry, but your solution solves nothing. The transporter could take a picture of the odometer and tweak the image. Your solution is only as secure as the input flow and you can't control it. A blockchain can't reflect physical reality. It can only reflect what someone said/says physical reality is. Additionally, they have to trust you to push the "right" data to the blockchain. If they are already trusting you, you can just run the database yourself.

rebelos 6y ago
I would just like to say that if anyone has a rational counterargument to this, I really want to hear it. This is precisely the observation past which the logic becomes less coherent in just about any conversation I've had on blockchain applications.
- beh9540 6y ago
  Maybe instead of an image, both parties could use an ODB reader that signs the mileage cryptographically, and pushes it to the blockchain? This way both parties could verify the transaction was completed as contracted (IE no joyrides). I'm still in the camp this probably doesn't need blockchain, but that would at least handle the image manipulation problem.
  - FunkyMJ 6y ago
    Why can't you just sign the image of the odometer?
- thekevan 6y ago
  Well in this specific example, what would they change to photo to? The case is to stop joyrides. Who would be able to take a joyride and end up with the odometer exactly as they had Photoshopped it to hours or days ago? But yes, depending on the application, photos can be manipulated. But that is stating the problem with using photos, not the timestamping app.
  - saati 6y ago
    It would be cool to have technology that tells you how long is a trip, oh wait, precise maps are hundreds of years old.
- sebmellen 6y ago
  Please see my comment in response to the grandparent comment. I think it will address your concerns with a rational counterargument. Basically, yes, you could, in theory, maybe, sort of, possibly, build a similar system without a public blockchain. But why? I'm sure there are people who can build houses with a few hand tools, but there's a reason we have power tools and heavy machinery — they are more efficient and fit the job better. The same goes for blockchain in this case. If you can point out where my logic is incoherent, please do, but to me the following: "oh, just set up a distributed git repo or database with checksums and append-only permissions that you control but replicate to other servers not controlled by you so that you can't tamper with the outputs and read from that global state and verify against the other mirrors of the database or repo every time you read from global state" sounds like a stupider alternative to blockchain. This is what blockchains were made for!!! Distributed consensus!
  - Spivak 6y ago
    I think the thing that you have to answer is why you need distributed consensus. You're a startup with a business relationship with your customers -- you're the common trusted party. Your customers are using your software so if they were worried about you cheating the system they (and you) have bigger problems since your business is reputation. Also what is the point of mining or and proof of $whatever system? The thing your customers provide is a signed attestation of some fact and you provide a signed attestation of the time that fact was received. Why is there a need to "vote" in way on what is true? This is just a database or honestly a folder of signed messages. And I say signed, but none of this really need to be cryptographic in any way since they're customers that could just authenticate to you which is as much a proof of their identity as any key.
    - sebmellen 6y ago
      You're right about everything but that we're the common trusted party. We have a relationship with the receiver. They want to be sure nothing happens in transit from origin. We do not have a business relationship with the transporters (many of whom are independent). The way the transporters know they're getting a fair deal is precisely because we are not the source of truth — a database outside of our control is (a blockchain, in this case). We're not voting on what is true, we're relying on the blockchain as an immutable representation of state. An append-only, distributed database that we do not control. And please don't downvote my comments out of a misunderstanding. That's juvenile.
swiley 6y ago
The ROM on most modern ECUs is cryptographicly protected isn't it? (I know it is on my 2006 Toyota Carola because I've looked at replacing it.) It would require cooperation from auto manufacturers but I'm sure you could come up with a scheme where the car itself signs and timestamps mileage data.
thekevan 6y ago
The solution solves the exact issue. A claim of fact is sent from one party to another and the blockchain--which is independent of either party's trust--holds that claim including who it was sent from, when, and what the claim was. The only thing it has the potential to not solve is the possibility of the party lying in that claim. In this specific example, what would they change to photo to? The case is to stop joyrides. Who would be able to take a joyride and end up with the odometer exactly as they had Photoshopped it to hours or days ago? But yes, depending on the application, photos can be manipulated. But that is stating the problem with using photos, not the timestamping app.
- bob33212 6y ago
  Gmail would be just as good. Have them send you an email as part of the handoff process. Time/date/photo will be documented in a source of Truth
  - pmccall777 6y ago
    "Doctors hate him..."
  - sebmellen 6y ago
    If you know anything about email headers, this is a bad solution. Are you suggesting that everyone has a shared Gmail account with one password? What happens when an email gets deleted?
    - deleted 6y ago
      [deleted]
    - SahAssar 6y ago
      What are you talking about? The suggestion was that the transporter simply send an email with the same data. The receiving party would get the email, and when an email is sent the sending party has no access to change it.
      - 6y ago
sebmellen 6y ago
No need to be so snarky. Could someone tweak the image? Of course. But as a practical concern, probably less than 20 people have the image manipulation skill it would take to do something like this in the ~20 minute handoff period. The transporters certainly don't. This is a bullshit argument, and you know it. And these pictures are not just of the odometer, but the entire car, including the VIN. Photoshopping all of this believably would cost you more than just paying the damages on a joyride. It's a non-issue. And I think you're misunderstanding something: the issue is not the time before the transporter get custody of the cars, but the many days that the cars are in transit cross-country. If the timestamp didn't exist at the time the transporter starts their journey, the next handoff knows something is up. As for already trusting us, our clients do, yes, but the point of this solution is to increase the trust-level of custodianship handoff between people who are not our clients. A blockchain is a great solution for this, and a database is simply an inferior solution. And NO, they don't have to trust us to "push the right data on-chain". This logic runs in a very simple SPA and is immediately verifiable on-chain, without using our software, because the blockchain's global state is open.
- doonesbury 6y ago
  I agree with the question: is anything really be solved here? No, not really. A db table of jpegs taken at different points in the hand off is essentially fine too. Carfax seems to so fine without blockchain. And really the bottom line is the end recipient: what recourse is there if the car shows up with too many miles?
  - sebmellen 6y ago
    The recourse is that the transporter doesn't get paid. Just a small adjustment to incentives massively changes the occurrence of damage to the car or anything similar. If you're arguing to put everything in a spreadsheet, or have us control the database and do without timestamping, I don't know what to say to you. Blockchain works here. Our business model isn't changing because you're saying we don't need it. Build a system like this yourself and we'll talk about it then. Carfax is a vertically integrated service with very little of the complexity we're dealing with. And of course you can make do without blockchain. People made do without electricity and power tools. But here it's a cheap, faster, easier to use, and more trusted alternative. What's wrong with that?
xupybd 6y ago
It makes it hard to alter historical data. It does not prove the data was correct to begin with. Blockchain isn't the only way to do this but it is a good way if you don't trust the parties holding the data not to attempt to alter it. You could avoid that by holding your own copy of the data and checking against that. What solution is best depends on the situation.
ninjanoel 6y ago
actually, the manipulation you mention isn't possible. the image would be 'hashed' when included on the blockchain signature, and it's computationally impossible to edit the image AND produce the same hash AND those changes being what you actually want the forgery to reflect. (producing the same haash is impossible enough)

rebelos 6y ago

I would just like to say that if anyone has a rational counterargument to this, I really want to hear it. This is precisely the observation past which the logic becomes less coherent in just about any conversation I've had on blockchain applications.

beh9540 6y ago
Maybe instead of an image, both parties could use an ODB reader that signs the mileage cryptographically, and pushes it to the blockchain? This way both parties could verify the transaction was completed as contracted (IE no joyrides). I'm still in the camp this probably doesn't need blockchain, but that would at least handle the image manipulation problem.
- FunkyMJ 6y ago
  Why can't you just sign the image of the odometer?
thekevan 6y ago
Well in this specific example, what would they change to photo to? The case is to stop joyrides. Who would be able to take a joyride and end up with the odometer exactly as they had Photoshopped it to hours or days ago? But yes, depending on the application, photos can be manipulated. But that is stating the problem with using photos, not the timestamping app.
- saati 6y ago
  It would be cool to have technology that tells you how long is a trip, oh wait, precise maps are hundreds of years old.
sebmellen 6y ago
Please see my comment in response to the grandparent comment. I think it will address your concerns with a rational counterargument. Basically, yes, you could, in theory, maybe, sort of, possibly, build a similar system without a public blockchain. But why? I'm sure there are people who can build houses with a few hand tools, but there's a reason we have power tools and heavy machinery — they are more efficient and fit the job better. The same goes for blockchain in this case. If you can point out where my logic is incoherent, please do, but to me the following: "oh, just set up a distributed git repo or database with checksums and append-only permissions that you control but replicate to other servers not controlled by you so that you can't tamper with the outputs and read from that global state and verify against the other mirrors of the database or repo every time you read from global state" sounds like a stupider alternative to blockchain. This is what blockchains were made for!!! Distributed consensus!
- Spivak 6y ago
  I think the thing that you have to answer is why you need distributed consensus. You're a startup with a business relationship with your customers -- you're the common trusted party. Your customers are using your software so if they were worried about you cheating the system they (and you) have bigger problems since your business is reputation. Also what is the point of mining or and proof of $whatever system? The thing your customers provide is a signed attestation of some fact and you provide a signed attestation of the time that fact was received. Why is there a need to "vote" in way on what is true? This is just a database or honestly a folder of signed messages. And I say signed, but none of this really need to be cryptographic in any way since they're customers that could just authenticate to you which is as much a proof of their identity as any key.
  - sebmellen 6y ago
    You're right about everything but that we're the common trusted party. We have a relationship with the receiver. They want to be sure nothing happens in transit from origin. We do not have a business relationship with the transporters (many of whom are independent). The way the transporters know they're getting a fair deal is precisely because we are not the source of truth — a database outside of our control is (a blockchain, in this case). We're not voting on what is true, we're relying on the blockchain as an immutable representation of state. An append-only, distributed database that we do not control. And please don't downvote my comments out of a misunderstanding. That's juvenile.

swiley 6y ago

The ROM on most modern ECUs is cryptographicly protected isn't it? (I know it is on my 2006 Toyota Carola because I've looked at replacing it.) It would require cooperation from auto manufacturers but I'm sure you could come up with a scheme where the car itself signs and timestamps mileage data.

thekevan 6y ago

The solution solves the exact issue. A claim of fact is sent from one party to another and the blockchain--which is independent of either party's trust--holds that claim including who it was sent from, when, and what the claim was. The only thing it has the potential to not solve is the possibility of the party lying in that claim. In this specific example, what would they change to photo to? The case is to stop joyrides. Who would be able to take a joyride and end up with the odometer exactly as they had Photoshopped it to hours or days ago? But yes, depending on the application, photos can be manipulated. But that is stating the problem with using photos, not the timestamping app.

bob33212 6y ago
Gmail would be just as good. Have them send you an email as part of the handoff process. Time/date/photo will be documented in a source of Truth
- pmccall777 6y ago
  "Doctors hate him..."
- sebmellen 6y ago
  If you know anything about email headers, this is a bad solution. Are you suggesting that everyone has a shared Gmail account with one password? What happens when an email gets deleted?
  - deleted 6y ago
    [deleted]
  - SahAssar 6y ago
    What are you talking about? The suggestion was that the transporter simply send an email with the same data. The receiving party would get the email, and when an email is sent the sending party has no access to change it.
    - 6y ago

sebmellen 6y ago

No need to be so snarky. Could someone tweak the image? Of course. But as a practical concern, probably less than 20 people have the image manipulation skill it would take to do something like this in the ~20 minute handoff period. The transporters certainly don't. This is a bullshit argument, and you know it. And these pictures are not just of the odometer, but the entire car, including the VIN. Photoshopping all of this believably would cost you more than just paying the damages on a joyride. It's a non-issue. And I think you're misunderstanding something: the issue is not the time before the transporter get custody of the cars, but the many days that the cars are in transit cross-country. If the timestamp didn't exist at the time the transporter starts their journey, the next handoff knows something is up. As for already trusting us, our clients do, yes, but the point of this solution is to increase the trust-level of custodianship handoff between people who are not our clients. A blockchain is a great solution for this, and a database is simply an inferior solution. And NO, they don't have to trust us to "push the right data on-chain". This logic runs in a very simple SPA and is immediately verifiable on-chain, without using our software, because the blockchain's global state is open.

doonesbury 6y ago
I agree with the question: is anything really be solved here? No, not really. A db table of jpegs taken at different points in the hand off is essentially fine too. Carfax seems to so fine without blockchain. And really the bottom line is the end recipient: what recourse is there if the car shows up with too many miles?
- sebmellen 6y ago
  The recourse is that the transporter doesn't get paid. Just a small adjustment to incentives massively changes the occurrence of damage to the car or anything similar. If you're arguing to put everything in a spreadsheet, or have us control the database and do without timestamping, I don't know what to say to you. Blockchain works here. Our business model isn't changing because you're saying we don't need it. Build a system like this yourself and we'll talk about it then. Carfax is a vertically integrated service with very little of the complexity we're dealing with. And of course you can make do without blockchain. People made do without electricity and power tools. But here it's a cheap, faster, easier to use, and more trusted alternative. What's wrong with that?

xupybd 6y ago

It makes it hard to alter historical data. It does not prove the data was correct to begin with. Blockchain isn't the only way to do this but it is a good way if you don't trust the parties holding the data not to attempt to alter it. You could avoid that by holding your own copy of the data and checking against that. What solution is best depends on the situation.

ninjanoel 6y ago

actually, the manipulation you mention isn't possible. the image would be 'hashed' when included on the blockchain signature, and it's computationally impossible to edit the image AND produce the same hash AND those changes being what you actually want the forgery to reflect. (producing the same haash is impossible enough)