摘要 |
<p>In a digital payment transactions system a broker generates and stores a secret number. The broker then generates a chain of hash values by successive operations of a hash function, using the secret number as the starting value. The broker then issues to the user a digitally encoded value from some way down the chain of hash values. The user generates a coin stick which comprises a chain of hash values starting with the value communicated by the broker. Subsequently, the broker can transfer further value to the user, without generating a new coin stick, by communicating a digitally encoded value from the broker's hash chain which precedes the value originally communicated to the user.</p> |