The preferred embodiments described herein provide a method and system for calling line authenticated key distribution. In one preferred embodiment, an authentication key is provided to a calling party if the calling party is phoning from a calling line associated with an authorized user. This preferred embodiment provides a more secure authentication key distribution method as compared to the prior art since preventing an unauthorized user from gaining access to an authorized user's calling line is more feasible and reliable than attempting to prevent an unauthorized user from obtaining an authorized user's password. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.