8. A method of controlling access to information of a first individual in response to a request for the information by a second individual and returning the information to the second individual based on the relationship between the first and second individuals, comprising the steps of: generating, at a local computer system that manages a first database, an ID token of the first individual and an ID token of the second individual from records stored in the first database using a one-way hash algorithm; transmitting a request for information about a relationship between the first and second individuals over a computer network from the local computer system to a third party computer system that manages a second database, the request including the ID tokens of the first and second individuals and identifying the one-way hash algorithm used to generate the ID tokens; receiving, at the local computer system, information about the relationship between the first and second individuals over the computer network from the third party computer system; and returning the information from the local computer system to the second individual based on the relationship between the first and second individuals.
8. A method of controlling access to information of a first individual in response to a request for the information by a second individual and returning the information to the second individual based on the relationship between the first and second individuals, comprising the steps of: generating, at a local computer system that manages a first database, an ID token of the first individual and an ID token of the second individual from records stored in the first database using a one-way hash algorithm; transmitting a request for information about a relationship between the first and second individuals over a computer network from the local computer system to a third party computer system that manages a second database, the request including the ID tokens of the first and second individuals and identifying the one-way hash algorithm used to generate the ID tokens; receiving, at the local computer system, information about the relationship between the first and second individuals over the computer network from the third party computer system; and returning the information from the local computer system to the second individual based on the relationship between the first and second individuals. 12. The method of claim 8 , wherein the request transmitted to the third party computer system over the computer network is formatted in accordance with an API that has been developed to work with the third party computer system.