>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). 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). -- Roger Clarke http://www.rogerclarke.com/ Xamax Consultancy Pty Ltd 78 Sidaway St, Chapman ACT 2611 AUSTRALIA Tel: +61 2 6288 6916 http://about.me/roger.clarke mailto:[email protected] http://www.xamax.com.au/ Visiting Professor in the Faculty of Law University of N.S.W. Visiting Professor in Computer Science Australian National University _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
