High-definition digital content is driving the need for higher security in the system-on-chip (SoC) devices used to transfer content between consumer devices. The number and types of these devices that store and play video and audio content is skyrocketing. Digital Content Protection (DCP) is a mechanism for the use of copyrighted content such as movies and music by authorized (licensed) personnel while blocking the use of this content by unauthorized persons.
One example of DCP is High-Bandwidth Digital Content Protection (HDCP) for controlling the flow of high-definition video (and audio) from source to display. The HDCP protocol for this transfer comprises authentication of receiving devices, encryption of the content, and procedures to revoke authorization for equipment no longer licensed to receive the HDCP content. Typically, HDCP encryption key storage requirements are just a few kilobytes, but the storage technology has to be low cost, highly secure, field-updatable, non-volatile and very reliable.
Besides media storage and transfer, secure encryption keys are found in many other devices, including encrypted flash memory drives, HDDs (hard disk drives) and electronic POS (Point of Sale) systems.
An HDCP system has three "pieces":
The following example shows a DVR connected to an HDTV. An entire set of encryption keys for one device requires about 2.5 Kbits of storage.
The following diagram illustrates a Digital TV SoC using Sidense OTP to securely store HDCP keys for decoding HDMI video.