Patent ID: 8321673

Claim:
A method of authentication between Digital Rights Management (DRM) agents, the method comprising: transferring an authentication request message including a first authentication information from a first DRM agent to a second DRM agent; receiving, by the first DRM agent, an authentication response message including a second authentication information from the second DRM agent after verifying whether the first authentication information is valid by the second DRM agent; and verifying, by the first DRM agent, whether the second authentication information is valid, wherein the first DRM agent receives from a Rights Issuer (RI), the first authentication information and a Rights Object (RO) for using content, wherein the second authentication information is transferred from the RI to the second DRM agent, wherein the RO is moved from the first DRM agent to the second DRM agent, wherein the authentication request message comprises one or more parameters of a sender device ID, sender nonce, timestamp, certificate chain, device Online Certificate Status Protocol (OCSP) response, message signature, and extensions, wherein the authentication response message comprises one or more parameters of a status, sender device ID, receiver device ID, request nonce, response nonce, session ID, certificate chain, device OCSP response, signature, and extensions, wherein the first authentication information comprises a first device OCSP response having certificate revocation information related to the first DRM agent, the first device OCSP response emanating from an OCSP server, and wherein the second authentication information comprises a second device OCSP response having certificate revocation information related to the second DRM agent, the second device OCSP response emanating from the OCSP server.