8 ms·

Not without a middlemen that we trust (cert authority in this case).

vlovich123 4y ago
That's certainly not true. P2P file transfer systems have long provided cryptographic guarantees that the file you receive hasn't been modified by anyone, even though you're fetching it from multiple untrusted sources simultaneously. Merkle trees have made this more efficient and offered maybe more guarantees, but being able to have files be transferred in a distributed fashion but impervious to corruption is not a new invention. The one thing cryptocurrencies have not figured out how to solve is the root problem of all PKI systems, which is establishing trust of identity.
- razemio 4y ago
  That is different use case. How would I prove that a file existed without a middlemen? I would gladly switch since the method I am currently using isn't exactly cheap.
  - joshstrange 4y ago
    Could you share you use-case and current method? I have no advice for you I'm just interested in how this is being used and who is providing said services.
  - woodruffw 4y ago
    > How would I prove that a file existed without a middlemen? How are you defining "middleman"? You can do this with any basic commitment scheme: take a cryptographically secure hash of your file and publish it somewhere that's either (1) trivially copyable, or (2) difficult to tamper with. Alternatively, you could do an online scheme where someone asks you for your proof and you present them with your hash after being challenged. That's a gross oversimplification, but it's the general idea. (In general, "prove that a file existed" is not something that you often want to do in the real world. What is it you're actually trying to accomplish?)
    - razemio 4y ago
      I work with ALOT of documents that have a deadline / need to be finished at a certain time. The blockchain helps me to proof mathematical in front of a curt that the file already existed at a given date. It is the most secure way that I know. A simple example of what I need without a middlemen. A student writes a thesis. The last time he is allowed to modify the file is friday evening. He can now send the file via mail or deliver in person to prove that the thesis was finished by then. However he then trusts either the mail server administration or the person at the front desk. This is fine in most cases and works like this since decades. I however do not want to trust a person or company. I do not want ANY possible explanation how I could have archived it in a different way.
      - threatofrain 4y ago
        Naive response here, but that particular use case seems solved by a central authority, where the school is the entity that (1) cares the most and (2) should other students or decentralised entities be involved in observing student progress?
      - prepend 4y ago
        It’s accepted in court that a simple email showing the file as an attachment is acceptable. Certainly blockchains are more trustworthy, but acceptableness in court is a pretty low bar. I mean having something signed on paper in front of a notary is acceptable. What cases are you involved with where a notary isn’t acceptable? Or a non-blockchain digital signature? I’m involved in really high dollar amount contracts and we just use pki-based digital signatures with a time stamp. Of course the time stamp could be fraudulent, but so could the notary’s stamp. But its acceptable in court and stands up to litigation. I also teach a class and would accept an email from the student as proof. To me that’s more reliable than me having to research some blockchain signature that I’m unfamiliar with. These are hypothetical use cases and don’t solve a real problem. And they certainly don’t justify paying transaction fees as they are now. It’s cheaper to just pay DocuSign.
        nouveaux 4y ago
nradov 4y ago
You trust those same certificate authorities every time you enter your credit card number in a web form.
- noman-land 4y ago
  That's because there were no other options. This is now another option.
guerrilla 4y ago
Now we trust mining pools which can become monopolies instead... Everyone seems to not see the positive feedback loops somehow. It results in the same system in the end.
- quickthrower2 4y ago
  You might enjoy this: https://youtu.be/J9nv0Ol-R5Q https://youtu.be/J9nv0Ol-R5Q
  - guerrilla 4y ago
    Summary for other people who might not know what this is: Nicholas Weaver, Lecturer at UC Berkeley after 9 years of research in cryptocurrency, lectures on Cryptocurrency as part of CS161: Computer Security. He explains the history of the data structures, some implementation choices, then a bunch of obvious lies from Bitcoin hucksters debunked, security problems, more history/lies debunked, the fraud and bs, computational power, power consumption, blah blah, everything is there in one hour. I think it could be a good thing to send to people so that they either come out of it knowing bitcoin is braindead or have to admit they're not capable of understanding it because they don't have the basic computer science knowledge :P
    - mw888 4y ago
      There’s a reason HN largely misses the innovation behind crypto, and it’s fairly simple. Bitcoin is not a technical innovation; Bitcoin’s value does not come from being an interesting data structure. Bitcoins value and genius is almost entirely economic in nature and hand waiving the (very simple) cryptography and computer science involved to analyze the economics is where the sophistication and avenue for critiques would come in. Technical knowledge gives you a menial job of auditing when it comes to Bitcoin. If you don’t have the economic sophistication and approach when discussing Bitcoin it only proves you are ignorant to what’s relevant.
      - guerrilla 4y ago

That's certainly not true. P2P file transfer systems have long provided cryptographic guarantees that the file you receive hasn't been modified by anyone, even though you're fetching it from multiple untrusted sources simultaneously. Merkle trees have made this more efficient and offered maybe more guarantees, but being able to have files be transferred in a distributed fashion but impervious to corruption is not a new invention. The one thing cryptocurrencies have not figured out how to solve is the root problem of all PKI systems, which is establishing trust of identity.

razemio 4y ago
That is different use case. How would I prove that a file existed without a middlemen? I would gladly switch since the method I am currently using isn't exactly cheap.
- joshstrange 4y ago
  Could you share you use-case and current method? I have no advice for you I'm just interested in how this is being used and who is providing said services.
- woodruffw 4y ago
  > How would I prove that a file existed without a middlemen? How are you defining "middleman"? You can do this with any basic commitment scheme: take a cryptographically secure hash of your file and publish it somewhere that's either (1) trivially copyable, or (2) difficult to tamper with. Alternatively, you could do an online scheme where someone asks you for your proof and you present them with your hash after being challenged. That's a gross oversimplification, but it's the general idea. (In general, "prove that a file existed" is not something that you often want to do in the real world. What is it you're actually trying to accomplish?)
  - razemio 4y ago
    I work with ALOT of documents that have a deadline / need to be finished at a certain time. The blockchain helps me to proof mathematical in front of a curt that the file already existed at a given date. It is the most secure way that I know. A simple example of what I need without a middlemen. A student writes a thesis. The last time he is allowed to modify the file is friday evening. He can now send the file via mail or deliver in person to prove that the thesis was finished by then. However he then trusts either the mail server administration or the person at the front desk. This is fine in most cases and works like this since decades. I however do not want to trust a person or company. I do not want ANY possible explanation how I could have archived it in a different way.
    - threatofrain 4y ago
      Naive response here, but that particular use case seems solved by a central authority, where the school is the entity that (1) cares the most and (2) should other students or decentralised entities be involved in observing student progress?
    - prepend 4y ago
      It’s accepted in court that a simple email showing the file as an attachment is acceptable. Certainly blockchains are more trustworthy, but acceptableness in court is a pretty low bar. I mean having something signed on paper in front of a notary is acceptable. What cases are you involved with where a notary isn’t acceptable? Or a non-blockchain digital signature? I’m involved in really high dollar amount contracts and we just use pki-based digital signatures with a time stamp. Of course the time stamp could be fraudulent, but so could the notary’s stamp. But its acceptable in court and stands up to litigation. I also teach a class and would accept an email from the student as proof. To me that’s more reliable than me having to research some blockchain signature that I’m unfamiliar with. These are hypothetical use cases and don’t solve a real problem. And they certainly don’t justify paying transaction fees as they are now. It’s cheaper to just pay DocuSign.
      - nouveaux 4y ago

nradov 4y ago

You trust those same certificate authorities every time you enter your credit card number in a web form.

noman-land 4y ago
That's because there were no other options. This is now another option.

guerrilla 4y ago

Now we trust mining pools which can become monopolies instead... Everyone seems to not see the positive feedback loops somehow. It results in the same system in the end.

quickthrower2 4y ago
You might enjoy this: https://youtu.be/J9nv0Ol-R5Q https://youtu.be/J9nv0Ol-R5Q
- guerrilla 4y ago
  Summary for other people who might not know what this is: Nicholas Weaver, Lecturer at UC Berkeley after 9 years of research in cryptocurrency, lectures on Cryptocurrency as part of CS161: Computer Security. He explains the history of the data structures, some implementation choices, then a bunch of obvious lies from Bitcoin hucksters debunked, security problems, more history/lies debunked, the fraud and bs, computational power, power consumption, blah blah, everything is there in one hour. I think it could be a good thing to send to people so that they either come out of it knowing bitcoin is braindead or have to admit they're not capable of understanding it because they don't have the basic computer science knowledge :P
  - mw888 4y ago
    There’s a reason HN largely misses the innovation behind crypto, and it’s fairly simple. Bitcoin is not a technical innovation; Bitcoin’s value does not come from being an interesting data structure. Bitcoins value and genius is almost entirely economic in nature and hand waiving the (very simple) cryptography and computer science involved to analyze the economics is where the sophistication and avenue for critiques would come in. Technical knowledge gives you a menial job of auditing when it comes to Bitcoin. If you don’t have the economic sophistication and approach when discussing Bitcoin it only proves you are ignorant to what’s relevant.
    - guerrilla 4y ago