Re: [Taler] age-restriction is about coins, not currencies

[Jacob Bachmeyer]

Schanzenbach, Martin wrote:
> I think use cases such as "soft binding" of pocket change to certain 
> products/services could still make sense.
> Eg. 10% for candy, 20% for games etc.
> Even that would be quite difficult to consolidate properly for businesses.
>   
This type of "budgeting aid" could be implemented entirely client-side 
and transparently with respect to the Taler protocols.  Users configure 
their wallets to set certain amounts aside for certain categories and 
indicate the category to associate with each transaction.  The wallet 
rejects the transaction (and offers access to revise the user's budget 
to permit the transaction) if the funds allotted to that category would 
be insufficient within the user's budget.
No other entity need even be able to see the user's categories or budget 
outline; the "restriction" is entirely in the user's wallet and can be 
effectively overridden if the user so chooses.  Businesses would receive 
only the standard tokens, with no indication that token X was budgeted 
for use with them.  The "soft binding" use case is entirely client-side, 
requiring only some additional metadata to preserve the budgeting 
information when synchronizing wallets.

-- Jacob