Methods and devices for authentication and key exchange

One feature pertains to a content accessing device for securing content. The content accessing device is provisioned with a cryptographic algorithm, and generates a symmetric key also known to a content storage device. The content accessing device sends a first authentication challenge to the content storage device, where the first authentication challenge is based on the cryptographic algorithm and the symmetric key. The content accessing device receives a second authentication challenge from the content storage device in response to sending the first authentication challenge, and determines whether the first authentication challenge is different from the second authentication challenge. If the second authentication challenge is different from the first authentication challenge the content accessing device sends a first response to the content storage device in response to the second authentication challenge.