@misc{MR15,
  author =    { Silvio Micali and Ronald L. Rivest },
  title =     { Method and system for micropayment transactions },
  howpublished = { U.S. Patent 8,983,874.  Issued March 17, 2015. },
  date =      { 2015-03-17 },
  OPTmonth =  { March 17, },
  OPTyear =   { 2015 },
  urla =      { <a href="http://www.google.com/patents/US8983874">google-patent-page</a> },
  abstract = { A micropayment system and method is presented for a payor
               U to establish payment to payee M for a transaction T, which
               typically has a very low value $T_V$.  The micropayment scheme
               minimizes the bank's processing costs, while at the same time
               eliminating the need for users and merchants to interact in order
               to determine whether a given micropayment should be selected for
               payment.  In one embodiment, the micropayment scheme includes time
               constraints, which require that an electronic check C for the
               transaction T be presented to a bank B for payment within a
               predetermined time/date interval.  In another embodiment,
               the micropayment scheme includes a selective deposit protocol,
               which guarantees that a user is never charged in excess of
               what he actually spends, even within a probabilistic framework.
               In another embodiment, the micropayment scheme includes a
               deferred selection protocol, which provides the bank with
               control and flexibility over the payment selection process.
             }
}