A certificate registry system is configured to issue authentication certificates to each one of a plurality of information providers and to maintain a root certificate corresponding to all of the authentication certificates. Each one of the authentication certificates links respective authentication information thereof to identification information of a corresponding one of the information providers. Each one of the authentication certificates includes a respective Instant Messaging (IM) screen name information of the information provider. The authentication certificates of the certificate registry are associated in a manner at least partially dependent upon at least one of a particular type of information that the information providers provide, a particular organization that the information providers are associated with, a particular type profession in which the information providers are engaged and a particular geographical region in which the information providers are located.