A method of and system for utilizing an access token to authenticate a client device for accessing a resource server include generating a session key for a communication session between the device and a resource server, deriving a nonce from the session key, and transmitting a request to an identity platform for authenticating the device to access the resource server, where the request includes the nonce. Upon confirmation of authentication, the method and system may include receiving an access token from the identity platform, the access token including information that confirms authentication of the device, and transmitting the access token to the resource server to enable access to the resource server, where the access token includes the nonce.