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This is not even the first paper by Dorit Ron and Shamir on Bitcoin; they did an analysis of the transaction graph earlier: http://eprint.iacr.org/2012/584.pdf‎

This is not even the first paper by Dorit Ron and Shamir on Bitcoin; they did an analysis of the transaction graph earlier: http://eprint.iacr.org/2012/584.pdf‎ http://eprint.iacr.org/2012/584.pdf‎ And that one too was quite poorly done; from the text, it actually seemed like they thought that "the blockchain" is a file stored on blockchain.info. Disappointing from the inventor of Shamir's Secret Sharing and differential cryptanalysis.

nwh 13y ago
> it actually seemed like they thought that "the blockchain" is a file stored on blockchain.info People seem to confuse that a lot. It's a badly named service at the best of times. I wonder how many legal requests the site will get from people believing they run Bitcoin.
- m_ram 13y ago
  I was about to argue with you about it not being very confusing, but then I read the "About" section on the front page: "This site allows you to navigate the bitcoin blockchain (a database which holds information about all transactions)." That really does make it sound like they are storing the centralized database for bitcoin. Edit: changed "storing a" to "storing the" to clarify my point per gojomo's reply.
  - gojomo 13y ago
    Blockchain.info is storing a centralized database for Bitcoin. Just not the centralized database... because there's not any official one. They're a value-added replica (via indexing & UI), not a constitutional authority. (They have some earned authority, by a record of useful service.)
    - ars_technician 13y ago
      It's not 'a centralized' database at all. Calling it that only adds to the confusion.
  - Crito 13y ago
    I can see where you are coming from, but how could you word that to be technically correct, succinct (not a full blown lecture on what bitcoin is), and not leave yourself open to giving people that impression? Bitcoin isn't the simplest concept around. Unless you are in the business of packaging up bitcoin for non-technical consumers, I think it is reasonable to expect your users to bring some knowledge about bitcoin to the table.
    - deleted 13y ago
      [deleted]
    - Philadelphia 13y ago
      "This site allows you to navigate through a copy of the bitcoin blockchain"
      - Crito 13y ago
        Yeah, that's definitely better. You might still have people falling into the weird "the blockchain is a bunch of html documents" hole though.
tlrobinson 13y ago
"Disappointing from the inventor of Shamir's Secret Sharing and differential cryptanalysis." Indeed, as I was reading the post I thought to myself "it couldn't be that Shamir, could it?" Oh.
eigenvalue 13y ago
I'd be shocked if the NSA hadn't "invented" differential cryptanalysis long before Shamir.
- caf 13y ago
  Does that matter? If two people independently invent the same thing, they're both inventors with equal standing. The classic example being Leibniz and Newton with regards to calculus of infintesimals.
  - ogreyonder 13y ago
    Apparently it matters to the good people of Marshall, Texas. According to them, Whitfield Diffie didn't invent public key encryption for exactly that reason. Yeah, I'm more than a little bitter about the technologically illiterate being allowed to judge complex technology.
- Crito 13y ago
  Isn't it a given that they did? They strengthened DES's s-boxes against it 10 or so years before it was publicly discovered iirc.
  - ars_technician 13y ago
    You're right, that's precisely why they changed DES.
betterunix 13y ago
I find the criticism of research papers on the part of Bitcoin supporters a bit ironic. Have people forgotten how poorly researched the original Bitcoin paper was?
- nullymcnull 13y ago
  Not sure what you mean by 'poorly researched'. Whatever it's flaws, it produced a hell of an innovative idea (or rather, a conglomeration of ideas into something innovative), and it has grown into something undeniably huge. Something people are building businesses upon. Something that is trading at over $900 USD/unit right now, despite countless rounds of naysayers decrying its intrinsic worthlessness and foretelling it's doom. Meanwhile these guys are merely riding on the huge waves which that 'poorly researched' paper left in its wake, trying to catch some press-coverage-by-association with their shoddy research. I'm failing to see the irony here, this is apples and oranges stuff. Really seems like you just wanted to sneer at 'Bitcoin supporters'.
  - betterunix 13y ago
    "Not sure what you mean by 'poorly researched'." I mean that it was poorly researched. There was no definition of security, no mention of the vast body of related work in digital cash or secure multiparty computation, a weak security analysis, no mention of the fact that polynomial time attacks are usually considered to indicate that a system is not secure (one would think that a different security model would require at least some justification), and so forth. That is not the mark of a solid research paper; the fact that Bitcoin has become so famous or that people are making money with it has no bearing on the quality of Satoshi's own research.
    - nullc 13y ago
      It was a simple white paper, offered up anonymously for only what it was. It made no claims which have been demonstrated to be false, which is more than you can say about the paper being discussed here. The Bitcoin whitepaper does what it says on the tin, you're the one inventing criteria for it that it doesn't meet. The white paper is also remarkably readable, which is something you can't say for most academic works.
oakwhiz 13y ago
We acquired the complete state of the Bitcoin transaction system [...] This required downloading 180,001 separate but linked HTML files [...] following the links backwards to the zeroth block [...] Each file was parsed in order to extract all the multisender/multireceiver transactions in it, and then the collection of transactions was encoded as a standard database on our local machine. This is definitely a very strange way of retrieving the blockchain for research purposes. Couldn't they have simply issued RPC calls to the regular bitcoind client after downloading the blockchain via the built-in peer-to-peer mechanism?
- carbocation 13y ago
  Yes. In fact, I'm sure (formally, "I suspect") that what you are describing is exactly how blockchain.info gets its data in the first place.
- runeks 13y ago
  No. Blockchain.info indexes the block chain by address. bitcoind indexes the block chain by transaction IDs (if you enable it). You'd still have to index the data you get from RPC calls by address if you want to track the movement of certain coins. It's a lot easier to just get it from blockchain.info.
ninguem2 13y ago
And the S in RSA.
bitcoin-truth 13y ago
Yes indeed. The first time they actually scraped the blockchain.info website, this time they've finally figured out that the blockchain is public and parsed a local blockchain.dat The New World is built on the results of that generation of cryptographers, but they can't keep up.

nwh 13y ago

> it actually seemed like they thought that "the blockchain" is a file stored on blockchain.info People seem to confuse that a lot. It's a badly named service at the best of times. I wonder how many legal requests the site will get from people believing they run Bitcoin.

m_ram 13y ago
I was about to argue with you about it not being very confusing, but then I read the "About" section on the front page: "This site allows you to navigate the bitcoin blockchain (a database which holds information about all transactions)." That really does make it sound like they are storing the centralized database for bitcoin. Edit: changed "storing a" to "storing the" to clarify my point per gojomo's reply.
- gojomo 13y ago
  Blockchain.info is storing a centralized database for Bitcoin. Just not the centralized database... because there's not any official one. They're a value-added replica (via indexing & UI), not a constitutional authority. (They have some earned authority, by a record of useful service.)
  - ars_technician 13y ago
    It's not 'a centralized' database at all. Calling it that only adds to the confusion.
- Crito 13y ago
  I can see where you are coming from, but how could you word that to be technically correct, succinct (not a full blown lecture on what bitcoin is), and not leave yourself open to giving people that impression? Bitcoin isn't the simplest concept around. Unless you are in the business of packaging up bitcoin for non-technical consumers, I think it is reasonable to expect your users to bring some knowledge about bitcoin to the table.
  - deleted 13y ago
    [deleted]
  - Philadelphia 13y ago
    "This site allows you to navigate through a copy of the bitcoin blockchain"
    - Crito 13y ago
      Yeah, that's definitely better. You might still have people falling into the weird "the blockchain is a bunch of html documents" hole though.

tlrobinson 13y ago

"Disappointing from the inventor of Shamir's Secret Sharing and differential cryptanalysis." Indeed, as I was reading the post I thought to myself "it couldn't be that Shamir, could it?" Oh.

eigenvalue 13y ago

I'd be shocked if the NSA hadn't "invented" differential cryptanalysis long before Shamir.

caf 13y ago
Does that matter? If two people independently invent the same thing, they're both inventors with equal standing. The classic example being Leibniz and Newton with regards to calculus of infintesimals.
- ogreyonder 13y ago
  Apparently it matters to the good people of Marshall, Texas. According to them, Whitfield Diffie didn't invent public key encryption for exactly that reason. Yeah, I'm more than a little bitter about the technologically illiterate being allowed to judge complex technology.
Crito 13y ago
Isn't it a given that they did? They strengthened DES's s-boxes against it 10 or so years before it was publicly discovered iirc.
- ars_technician 13y ago
  You're right, that's precisely why they changed DES.

betterunix 13y ago

I find the criticism of research papers on the part of Bitcoin supporters a bit ironic. Have people forgotten how poorly researched the original Bitcoin paper was?

nullymcnull 13y ago
Not sure what you mean by 'poorly researched'. Whatever it's flaws, it produced a hell of an innovative idea (or rather, a conglomeration of ideas into something innovative), and it has grown into something undeniably huge. Something people are building businesses upon. Something that is trading at over $900 USD/unit right now, despite countless rounds of naysayers decrying its intrinsic worthlessness and foretelling it's doom. Meanwhile these guys are merely riding on the huge waves which that 'poorly researched' paper left in its wake, trying to catch some press-coverage-by-association with their shoddy research. I'm failing to see the irony here, this is apples and oranges stuff. Really seems like you just wanted to sneer at 'Bitcoin supporters'.
- betterunix 13y ago
  "Not sure what you mean by 'poorly researched'." I mean that it was poorly researched. There was no definition of security, no mention of the vast body of related work in digital cash or secure multiparty computation, a weak security analysis, no mention of the fact that polynomial time attacks are usually considered to indicate that a system is not secure (one would think that a different security model would require at least some justification), and so forth. That is not the mark of a solid research paper; the fact that Bitcoin has become so famous or that people are making money with it has no bearing on the quality of Satoshi's own research.
  - nullc 13y ago
    It was a simple white paper, offered up anonymously for only what it was. It made no claims which have been demonstrated to be false, which is more than you can say about the paper being discussed here. The Bitcoin whitepaper does what it says on the tin, you're the one inventing criteria for it that it doesn't meet. The white paper is also remarkably readable, which is something you can't say for most academic works.

oakwhiz 13y ago

We acquired the complete state of the Bitcoin transaction system [...] This required downloading 180,001 separate but linked HTML files [...] following the links backwards to the zeroth block [...] Each file was parsed in order to extract all the multisender/multireceiver transactions in it, and then the collection of transactions was encoded as a standard database on our local machine. This is definitely a very strange way of retrieving the blockchain for research purposes. Couldn't they have simply issued RPC calls to the regular bitcoind client after downloading the blockchain via the built-in peer-to-peer mechanism?

carbocation 13y ago
Yes. In fact, I'm sure (formally, "I suspect") that what you are describing is exactly how blockchain.info gets its data in the first place.
runeks 13y ago
No. Blockchain.info indexes the block chain by address. bitcoind indexes the block chain by transaction IDs (if you enable it). You'd still have to index the data you get from RPC calls by address if you want to track the movement of certain coins. It's a lot easier to just get it from blockchain.info.

ninguem2 13y ago

And the S in RSA.

bitcoin-truth 13y ago

Yes indeed. The first time they actually scraped the blockchain.info website, this time they've finally figured out that the blockchain is public and parsed a local blockchain.dat The New World is built on the results of that generation of cryptographers, but they can't keep up.