> On 2017/Dec/07, at 1:41 PM, Roger Clarke <[email protected]> wrote: > >> On 07/12/17 12:35, Roger Clarke wrote: >>> [But shares are a form of commodity, i.e. they are undifferentiated, and >>> no-one cares whose they used to be, only that they're mine now. Put >>> another way, whereas provenance matters with some categories of goods >>> (objets d'art being a good example), it matters not at all with shares, >>> because the registry authenticates the holding beng sold, and warrants that >>> the shares are valid. > > At 13:19 +1100 7/12/17, Hamish Moffatt wrote: >> Nobody cares who had the $5 note in my wallet before me either, but that's >> what the Bitcoin blockchain tracks. Currently it's 144Gb according to >> https://blockchain.info/charts/blocks-size. Fascinating reading no doubt. > > The $5 note is a single physical object that isn't replicable (at this stage, > pending progress with 3D printing!). > > Value-authentication of the $5 note is performed by inspecting it and > comparing its appearance against people's expectations (a good forgery being > worth as much as one printed by the official Mint).
That's cash, but most of our money is not at home or on our persons as actual cash, it is in a bank as bits on a banking computer or held in some other assets. There is not a one-to-one correspondence between actual physical cash and bits of money in the bank. Which is probably less safe than bitcoin or stone money from then island of Yap. > A Bitcoin bit-string is born-digital, and readily replicable. > > So some other form of value-authentication is needed. The method used is to > record all aspects of the string's provenance, and ensure that the provenance > is replicated by 'enough' entities, with 'enough' incentive for 'enough' of > those entities to check that the content is valid. > > > Re the 144GB, you do have to wonder about the scalability factor with > blockchaining of frequently transacted digital objects. (However, that's a > separate issue from whether blockchain techniques have anything to offer to > transactions involving commodities). -- Kim Holburn IT Network & Security Consultant T: +61 2 61402408 M: +61 404072753 mailto:[email protected] aim://kimholburn skype://kholburn - PGP Public Key on request _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
