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Bitcoin Privacy

How To Make a Bitcoin Address With a TI-89 Calculator 56

sarahnaomi writes: The power of Bitcoin is giving your dusty old TI-89 calculator a second chance of being useful. Matt Whitlock, who helped make one of the world's first Bitcoin ATMs, is at it again. In a video posted on to Vimeo, he showed how using the calculator once only used for high school geometry and a 12-sided die makes a secure address for your Bitcoin account. The video self-explanatory. Load up your calculator with the code, roll it 72 times and enter the number rolled into it. After that, the calculator pumps out a private key and address.
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How To Make a Bitcoin Address With a TI-89 Calculator

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  • Are you retarded? (Score:4, Insightful)

    by rebelwarlock ( 1319465 ) on Sunday April 05, 2015 @05:37AM (#49408945)
    I'm not rolling a die 72 times and manually entering each result.
    • by gl4ss ( 559668 )

      yeah.. why can't you just smash numbers in random until you get enough for a good seed?

      • by itzly ( 3699663 )

        Or take a picture of your room, calculate a hash, and be done with it.

        • In theory, your "you mama" joke approach should work. (For a good enough hash. Things like SHA2 or SHA3/Keccak should be okay).

          But, in practice, that would require:
          - a device with a camera (well, duh...)
          - a device that is easy programmable enough (because very few camera are known to automatically display a has on the screen by default)
          - a device that is *offline* (the whole point of doing it on something different than a laptop is to do it on a device that has low risk of virus/trojan/backdoor)

          That strongl

          • smartphone aren't offline

            They can be made so easily enough.

            • by gox ( 1595435 )

              The device itself should not allow the possibility of the data becoming online at a future time. That rules out systems with connection capabilities that also have memory.

              • by itzly ( 3699663 )

                Smash it with a hammer, and throw away the pieces. If your secret key isn't worth a new phone, it's not worth going through all this trouble anyway.

                • by gox ( 1595435 )

                  I don't think anyone would go through all this trouble for security, it is just a geek entertainment thing.

                  Having said that, keeping around an offline device for secure storage is not too bad an idea. If you have a RasPi lying around, it's all you need to generate secure keys, store 2FA secrets, and anything else that is best preserved cold.

              • If the device becomes online without you consent in the future, it means it's not in your hands anymore. Thus *any* device will be vulnerable to prying eyes.

                • by gox ( 1595435 )

                  I assumed wonkey_monkey is talking about making smartphones temporarily offline. So it does become online with your consent. It could also connect without you even noticing.

                  Also, any device is vulnerable, but not equally. A lot needs to happen for the encrypted data on my old laptop with no wi-fi capability to leak out.

          • Re: (Score:3, Interesting)

            by Reaper9889 ( 602058 )

            Well, that was one of the more unexpected "you mama" joke: Your mama is so fat that she shows up in a post mentioning only your room!

            I want to note that just in case someone thinks so: You can not roll two 6-sided die and add them together and get a 12-sided dice - first of all you cant roll 1 and you roll 7 way too often. What you can do is have two rolls of a 6-sided die. Say you first roll x and then y. If y is even you rolled x otherwise you rolled 6+x. This gives you precisely 12 different equally like

          • by itzly ( 3699663 )

            - point-and-shoot camera usually don't have an easy way to install your "picture hashing your mom as a random number generator" system

            Take SD card from regular digital camera (or phone), stick it in an off-line linux laptop, and run sha256sum. No programming required.

          • by itzly ( 3699663 ) on Sunday April 05, 2015 @06:26AM (#49409059)

            In theory, your "you mama" joke approach should work

            No, yo momma is too big for a hash.

            • No, yo momma is too big for a hash.

              +Funny.

              To keep with today's theme:
              - Yo mama's so fat, her picture need to "Google Maps" to be viewable
              - Yo mama's so fat, said picture can provide secure hash random seeds for the rest of the whole internet's existence.

          • by jonwil ( 467024 )

            Canon digital camera with CHDK (Canon Hack Development kit for adding new features to Canon cameras) should be able to do this if someone was to write the code for it.

            So it has a camera, its programmable and it (at least the Canon PowerShot SX130IS sitting next to me anyway) has no network connectivity.

            And its probably easier to find a camera that is supposed by CHDK than to get hold of an ancient PDA AND a camera dongle for it.

          • A Canon camera with CHDK on it would fit all of your requirements.
      • by grumling ( 94709 )

        Tune a radio to white noise, sample the audio 72 times and use that. Can I patent cosmic background radiation encryption?

      • Instead of taking values of keys (which would be a poor seed), take timing of keypresses. If the calculator runs at 1MHz, run a loop that takes 10uS per iteration, and count how many iterations it took between keypresses, modulo 100. No human is capable of timing their keypresses to 1 millisecond with *any* precision, nor correlate the keypresses to any fixed multiple of 10us period, so the sub-millisecond part of timing is entirely random.

        So, you're getting about 7 bits of entropy per keypress. Double that

    • Re: (Score:2, Insightful)

      by dbIII ( 701233 )
      It's a bitcon article so asking if the suckers drawn in the scheme are retarded is considered rude.
      "It's the future" - it's like that thing in Cryptonomicon only not backed by anything of value and it's founder has gone into hiding.
      • by ultranova ( 717540 ) on Sunday April 05, 2015 @10:30AM (#49409863)

        It's a bitcon article so asking if the suckers drawn in the scheme are retarded is considered rude.

        More importantly, calling people who use Bitcoin retarded or suckers doesn't actually constitute a strong argument against it.

        only not backed by anything of value

        Bitcoin is backed by the goods and services available in exchange of it, just like any other currency.

        and it's founder has gone into hiding.

        The founders of most currencies currently at use are dead.

        • Bitcoin is backed by the goods and services available in exchange of it

          No, its not. The quantity of a particular good or service equating to a bitcoin can vary wildly in a very short period of time.

          Bitcoin, like other currencies, it backed by faith. And a lot of that faith has to do with speculation not commerce.

          Bitcoin is not a currency, it currently fails as a store of value. Could that change, possibly, but unlikely in the short term.
          Bitcoin is a speculative instrument.
          Bitcoin's real use is as a payment system. During payment processing bitcoins are generally not he

  • Seriously? No, really, seriously?

    You couldn't figure out ANY way to get sufficiently random numbers out of that calculator just from human interaction?

    • by itzly ( 3699663 )

      Of course, but that's not cool enough.

  • Good point from TFA: " it’s secure because it never connects with a “NSA backdoored” computer when generating it", which actually makes sense. Many people have a calculator like this which provides a suitable air-gapped and safe computing resource.
  • by wonkey_monkey ( 2592601 ) on Sunday April 05, 2015 @08:55AM (#49409451) Homepage

    The video self-explanatory.

    Ah.

    Load up your calculator with the code, roll it 72 times

    Okay, done that, but nothing much happened. What is the 12-sided die for?

  • Mycelium entropy released a offline hardware based paper wallet generator which allows you to generate secure single wallets or Shamir’s 2-of-3 Secret Sharing Scheme wallets with a single click and even use your own seed if you are especially paranoid

    The unit was 40 dollars - https://mycelium.com/entropy [mycelium.com] https://mycelium.com/assets/en... [mycelium.com]

    or you could just get one of many hardware wallets - https://bitcointalk.org/index.... [bitcointalk.org]

  • Did they try finding an entropy source on-calculator like Linux uses for /dev/random? It seems that reading from an unconnected address occasionally yields different values...maybe characterize the distribution to get a lower bound on its entropy, then let it run automated for however many seconds or minutes it takes to accumulate enough. It would be easier on the user than rolling a die a bunch. (Of course, it might be hard to rule out systematic trends in the bits returned without intimate knowledge of th

  • How about my TI-86?

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