A method of authentication comprising: receiving, from a first authentication device of a first network employing a first wireless protocol and a first authentication protocol, a first authentication message for authenticating a mobile device to the first network, wherein the first authentication message includes a first authentication attribute, wherein an authentication attribute includes an authentication credential of the mobile device or an indication that the mobile device is associated with a subscription associated with the second network; generating, responsive to receiving the first authentication message, a second authentication attribute based on the first authentication attribute; transmitting, responsive to generating the second authentication attribute, a second authentication message including the second authentication attribute to a second authentication device of a second network employing a second wireless protocol that is different from the first wireless protocol and a second authentication protocol; receiving, responsive to transmitting the second authentication message, a third authentication message from the second authentication device of the second network employing the second authentication protocol; and transmitting, responsive to receiving the third authentication message, a fourth authentication message to the first authentication device of the first network employing the first authentication protocol; wherein at least the first authentication message or the second authentication message is selected from a group consisting of an access request and an authentication request, and the third authentication message or the fourth authentication message is selected from a group consisting of a challenge and an access accept; wherein the first authentication protocol is based on a first specification that is a Wireless Roaming Intermediary Exchange specification or a Worldwide Interoperability for Microwave Access, WiMAX, R3 protocol interface specification; and wherein the second authentication protocol is based on a second specification that is the Wireless Roaming Intermediary Exchange specification or the WiMAX R3 protocol interface specificiation, and the first specification is different from the second specification. receiving, from a first authentication device of a first network employing a first wireless protocol and a first authentication protocol, a first authentication message for authenticating a mobile device to the first network, wherein the first authentication message includes a first authentication attribute, wherein an authentication attribute includes an authentication credential of the mobile device or an indication that the mobile device is associated with a subscription associated with the second network; generating, responsive to receiving the first authentication message, a second authentication attribute based on the first authentication attribute; transmitting, responsive to generating the second authentication attribute, a second authentication message including the second authentication attribute to a second authentication device of a second network employing a second wireless protocol that is different from the first wireless protocol and a second authentication protocol; receiving, responsive to transmitting the second authentication message, a third authentication message from the second authentication device of the second network employing the second authentication protocol; and transmitting, responsive to receiving the third authentication message, a fourth authentication message to the first authentication device of the first network employing the first authentication protocol; wherein at least the first authentication message or the second authentication message is selected from a group consisting of an access request and an authentication request, and the third authentication message or the fourth authentication message is selected from a group consisting of a challenge and an access accept; wherein the first authentication protocol is based on a first specification that is a Wireless Roaming Intermediary Exchange specification or a Worldwide Interoperability for Microwave Access, WiMAX, R3 protocol interface specification; and wherein the second authentication protocol is based on a second specification that is the Wireless Roaming Intermediary Exchange specification or the WiMAX R3 protocol interface specificiation, and the first specification is different from the second specification.