Title:
2次的情報信号のRLLコードシーケンスへの付加及びRLLコードシーケンスから2次的情報信号を取り出すための装置及び方法
Document Type and Number:
Japanese Patent JP4738711
Kind Code:
B2
Abstract:
A method and device for adding or extracting a secondary information signal to/from a runlength-limited code sequence, includes detecting a polarity of a runlength at a first predetermined position of the runlength-limited code sequence and setting a parameter reflecting the degree of freedom that is present in the runlength-limited channel code, e.g., the selection of a merging bit pattern in the CD-standard, on the basis of the detected polarity so as to obtain a predetermined polarity of a runlength at a subsequent second predetermined position of the runlength-limited code sequence. The predetermined polarity then corresponds to a binary value of the secondary information. Thus, a side-channel with a small capacity is provided, which is positioned very close to the physical channel such that the secondary information is hard to be detected from the EFM bit stream. Therefore, the side-channel can be used as a hidden channel for copy protection purposes.
Inventors:
Coenwillem MJ
Tarstra Johann Sea
Sterling antonius am
Haems Skark Jacobs PJ
Tarstra Johann Sea
Sterling antonius am
Haems Skark Jacobs PJ
Application Number:
JP2002520227A
Publication Date:
August 03, 2011
Filing Date:
July 31, 2001
Export Citation:
Assignee:
Koninklijke Philips Electronics N.V.
International Classes:
G11B20/14; G11B20/00; G11B20/10; H03M5/14; H03M7/14; H03M7/46
Foreign References:
| WO2002001560A1 | ||||
| EP0918326A1 |
Attorney, Agent or Firm:
Susumu Tsugaru
Fueda Shusen
Sakiko Shibata
Fueda Shusen
Sakiko Shibata