Patent ID: 7668314
Filing Date: 2010-02-23
Classification: H04L,H04N

Abstract:
1. An encrypted data communication system for communicating an encrypted stream from a device at a transmitting end to a device at a receiving end, the encrypted stream being generated by encrypting a video stream with a start code which is a unique code, wherein the device at transmitting end includes: an encryption processing unit for encrypting at least one part of the video stream, without the start code, by an exclusive-OR operation of a random number and at least one part of the video stream, and a transmitter for transmitting the encrypted stream including the video stream at least one part of which is encrypted without the start code, and the start code being not encrypted, and a synchronization marker which is arranged before or after the start code; and wherein the device at receiving end includes: a receiver for receiving the encrypted stream, a detector for detecting a sequence of the start code and the synchronization marker from the received encrypted stream to determine that the detected start code is valid, and a decryptor for decrypting the received video stream at least one of which is encrypted without the start code, based on a position at which the start code is detected.