AA system in which a requesting entity seeking access to a controlled resource is authenticated by an access authentication component includes the requesting entity initially opening a security account with the access authentication component, the access authentication component establishing and maintaining a record including information pertaining to the account and being retrievable based on a unique identifier for the requesting entity, and associating a public key of a public-private key pair with the record; the requesting entity originating an electronic message and generating a digital signature using a private key of the key pair, and sending the digitally signed electronic message to the access authentication component with the unique identifier; authenticating the electronic message using the public key associated with the record identified by the unique identifier; and upon successful authentication, authenticating access to the controlled resource. Security information is considered in authenticating the requesting entity.