Abstract: A method and a system for performing a transaction between at least one first party and at least one second party are disclosed. A data network connects data input/output terminals of the parties. In the data network, a secure and trusted transaction server is provided, in which a profile of the parties is registered, having a party identifier identifying a particular party, and authentication data for authenticating the party and data sent by the party. The parties communicate with each other through the transaction server by means of various transaction messages, which are digitally signed using a table of random numbers and a hashing operation, wherein the table of random numbers is generated by reading a token.