The Digital Transmission Content Protection (DTCP) defines a cryptographic protocol for protecting audio /video entertainment content from illegal copying, intercepting and tampering as it traverses high performance digital buses, such as the IEEE 1394 standard. DTCP ensures that the copy protection mechanism is built into Digital Audio/Video devices themselves (in addition to Traditional Encryption). This seminars will outline the basic principles of cryptography; and tells us about the cryptographic functions used in it. It will briefly look at the IEEE1394 standard where it is being implemented. This seminars will nevertheless discuss DTCP including different layers of copy protection and some implementation aspects. This seminars also provides a case study of typical use of content protection in Digital TV and Digital VCR implementation. A product solution could include hardware and software implementation for the Digital Transmission Content Protection mechanism.