Patent ID: 8165295
Filing Date: 2012-04-24
Classification: H04L,H04N

Abstract:
1. A data transmission method comprising the steps of: performing encryption for information data included in a data packet having a data flag formed of a first combination of a plurality of inhibited codes that are not used as information codes representing information, the information data being formed without using the inhibited codes, so as not to generate the inhibited codes in order to generate encrypted information data that includes no inhibited codes; replacing the first combination of the plurality of inhibited codes in the data flag in the data packet with a second combination of the inhibited codes, the second combination being different from the first combination, to form an encrypted data packet that has the replaced data flag and that includes the encrypted information data; and transmitting the encrypted data packet, wherein when the transmitted encrypted data packet does not include decrypting information, a type of original information data represented by identification data before the replacing is not recognized and reproduced information data based on encrypted information data included in the encrypted data packet is not processed as data belonging to a same type of information as the information data represented by identification data before the replacement of the first combination with the second combination.