A system and method thereof, comprising means for: communicating through at least one computer network interface with each of (i) a plurality of providers of accountable resources, and (ii) a plurality of registrars which register clients, each client having access to accountable resources of providers, and maintain client-associated accounts therewith; generating a token verifying that a client is authenticated by a registrar; logging accountable transactions identifying a client-associated account and a transaction valuation, maintained by the registrar; and periodically accounting for the logged accountable transactions between respective registrars and respective providers; wherein a valuation of the accountable transaction is dependent at least on information conveyed in the token.