Data transmission method and data transmission apparatus

• US 20060018468A1
• Filed: 10/01/2004
• Published: 01/26/2006
• Est. Priority Date: 10/20/2003
• Status: Abandoned Application

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ichimura, Gen, Toba, Kazuaki
• Application Number:
  US10/954,191
• Publication Number:
  US 20060018468A1
• Time in Patent Office: Days
• US Class Current: 380/200
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/606 by securing the transmission between two devices or processes
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/23473 by pre-encrypting
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

The present invention relates to a data transmission method used in the data transmission system. The data transmission method decrypts encrypted data, applies again encryption effective in the transmission system at transmission time so as to transmit the encrypted data from a sending side to a receiving side. The receiving side applies decryption effective only at the transmission time to the transmitted data to obtain clear text.

Claims

1. A data transmission method that transmits an input source data that has been encrypted using a first encryption scheme into the data form that a receiver can decrypt, comprising the steps of:

decrypting an encryption according to the first encryption scheme applied to the input source data;

applying predetermined process to data in a predetermined position in the decrypted source data;

encrypting the source data in which the predetermined process has been applied to the data in a predetermined position into the data form that the receiver can decrypt using a second encryption scheme different from the first encryption scheme; and

transmitting the data that has been encrypted according to the second encryption scheme to the receiver.

2. The data transmission method according to claim 1, wherein the data in a predetermined position to which predetermined process is applied does not involve reproduction of the source data performed in the receiver.

3. The data transmission method according to claim 1, wherein the predetermined process applied to the data in a predetermined position in the decrypted source data is substitution with other data.

4. The data transmission method according to claim 1, wherein the predetermined process applied to the data in a predetermined position in the decrypted source data is deletion of the data in a predetermined position.

5. The data transmission method according to claim 1, comprising:

processing a part of data that is not required in a decryption unit, the data conforming to a format having an unallocated region such as a reserved region; and

applying encryption to the processed data using the second encryption scheme.

6. A data transmission apparatus that transmits an input source data that has been encrypted using a first encryption scheme into the data form that a receiver can decrypt, comprising:

decryption means for decrypting an encryption according to the first encryption scheme applied to the input source data;

data process means for applying predetermined process to data in a predetermined position in the decrypted source data;

encryption means for encrypting the source data in which the predetermined process has been applied to the data in a predetermined position into the data form that the receiver can decrypt using a second encryption scheme different from the first encryption scheme; and

transmission means for transmitting the data that has been encrypted according to the second encryption scheme to the receiver.

7. The data transmission apparatus according to claim 6, wherein the data in a predetermined position to which predetermined process is applied does not involve reproduction of the source data performed in the receiver.

8. The data transmission apparatus according to claim 6, wherein the predetermined process applied to the data in a predetermined position in the decrypted source data is substitution with other data.

9. The data transmission apparatus according to claim 6, wherein the predetermined process applied to the data in a predetermined position in the decrypted source data is deletion of the data in a predetermined position.

10. The data transmission apparatus according to claim 6, comprising:

processing a part of data that is not required in a decryption unit, the data conforming to a format having an unallocated region such as a reserved region; and

applying encryption to the processed data using the second encryption scheme.

11. A data receiving apparatus that receives the transmitted encrypted reproduction data and reproduces the data, the data transmitted to the receiver having been obtained by decrypting an encryption according to the first encryption scheme applied to the input source data that has been encrypted, applying predetermined process to data in a predetermined position in the decrypted source data, encrypting the source data in which the predetermined process has been applied to the data in a predetermined position into the data form that the receiver can decrypt using a second encryption scheme different from the first encryption scheme, the receiver comprising:

reception means for receiving the encrypted reproduction data;

reproduction means for reproducing the source data;

decryption means for decrypting the encrypted reproduction data received by the reception means;

detection means for detecting predetermined process applied to a part of the decrypted reproduction data; and

reproduction data supplement means for generating reproduction data that the reproduction means can reproduce, which is substantially the same as a part of the source data that has been processed, and adding the reproduction data to the detected processed portion so as to supply the reproduction means with the supplemented data.

12. The data transmission apparatus according to claim 11, wherein the predetermined process applied to a part of the reproduction data is deletion of a part of the source data.