Re: decentralized wallets and payment processors

> On 7 Apr 2015, at 11:39, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> 
> My model is very simple.  A wallet has a balance.  It has a way to pay another entity.  It has deposits and withdrawals.  
> 
> That's the main part of it, there's other things like an address book and integrations API, but that's secondary.
> 
> What I discovered in programming a wallet with linked data is that when you program the single user case, the multi user case is not too much more complicated.  So whilst I had originally considered writing one system for the wallet and one for the payment processor, I have found the same code can largely be reused for both.  This lead me to realize that making the browser wallet multi user is not a lot of work, and offers interesting new functionality.
>  
> 
> A related perspective is on wallet synchronisation.  Imagine that a user have the same wallet installed on a number of different devices. The aim is to synchronise changes when the wallets are online. For instance, copying new receipts to the other wallets. Synchronisation would also apply to user preferences, and to payment instruments.  This could be implemented via keeping a copy of wallet in the cloud, or via peer to peer connections where each instance of the wallet has the list for the set of instances.   The peer to peer approach is more complex as you need to allow for devices being offline so that they have to be synchronised later when they next go online.  Moreover in principle, there could be more than one wallet with new receipts etc.  One solution involves a mechanism for electing one of the devices as a temporary master that manages version control. Another solution is based upon clock synchronisation.
> 
> Im very glad you brought up syncronization, because this is exactly the challenge I ran into.  I have one wallet on my desktop, one in the office, and one in the cloud.  I'd like them to be consistent without having to worry.  Im still looking for a good way to solve this, right now I'm using an always on web server with websockets.  But the P2P approach sounds very attractive, I just dont know how to do it.

You may want to look at: http://en.wikipedia.org/wiki/Leader_election

The problem gets more interesting when there is a very large number of nodes, whereupon self-organising scale free networks of relationships provides an efficient solution in combination with election of leaders.

—
   Dave Raggett <dsr@w3.org <mailto:dsr@w3.org>>