A method and system for allowing access to an exchange by a casual user without compromising exchange security. The present invention allows a casual user to provide required input and complete simple business transactions without becoming a registered member of the exchange. The system knows what information to provide to or to collect from the casual user and provides him with a context sensitive personal identification number (CS-PIN) to allow access for that purpose. The method of the invention comprises: receiving a request from an external application; generating and transmitting an external message to the casual user containing information on accessing said casual access application; generating a context sensitive personal identification number upon access of the casual access application by the casual user using the information contained in the external message; storing the CS-PIN in a CS-PIN holder accessible to the casual user; and completing the request upon access by the casual user using the CS-PIN.