For digital rights management (DRM), a method for performing authentication between a device and a portable storage, which is performed by the device, includes transmitting a first key to the portable storage, receiving a third key and a first encrypted random number obtained by encrypting a first random...http://www.google.com.hk/patents/US8209535?utm_source=gb-gplus-share專利 US8209535 - Authentication between device and portable storage
