The method includes the steps of receiving at the PEAD first digital data representing the transaction request. The PEAD provides information to the user regarding an ability to approve the transaction request. When the transaction request is approved by the user, the PEAD receives second digital data representing the electronic service authorization token. A remote agent server may provide a bridge between the electronic transaction system and the PEAD. In another embodiment, the private key is stored on the portable device, encrypted. The decryption key is stored outside of the device, at a trusted 3.sup.rd party location. When the user attempts to make a signature the software sends a request for the decryption key, along with the user's password or pass phrase keyed in at the keyboard of the PDA, smart phone, or cell phone, to a server belonging to the trusted 3.sup.rd party.