Title:
DATA TRANSMITTING APPARATUS
Document Type and Number:
WIPO Patent Application WO/2006/051741
Kind Code:
A1
Abstract:
A time required for a wiretapper to decrypt an encrypted text is significantly increased to provide a data transmitting apparatus having a high concealing characteristic. In a data transmitting apparatus (17105), a multilevel encoding part (111) switches a plurality of key information to generate a multilevel code sequence in which the average values of signal levels are different, and then combines the generated multilevel code sequence with information data to generate a multilevel signal having a level corresponding to the combination of the two signal levels. A light modulating part (125) converts the multilevel signal to a modulated signal of a predetermined modulation scheme for transmission. In a data receiving apparatus (17205), a light demodulating part (219) demodulates the modulated signal received thereby to the multilevel signal. A multilevel demodulating part (212) switches a plurality of key information to generate a multilevel code sequence in which the average values of signal levels are different, and then identifies the multilevel signal based on this generated multilevel code sequence to reproduce the information data.
Inventors:
IKUSHIMA TSUYOSHI
FURUSAWA SATOSHI
FUSE MASARU
FURUSAWA SATOSHI
FUSE MASARU
Application Number:
PCT/JP2005/020308
Publication Date:
May 18, 2006
Filing Date:
November 04, 2005
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD (JP)
IKUSHIMA TSUYOSHI
FURUSAWA SATOSHI
FUSE MASARU
IKUSHIMA TSUYOSHI
FURUSAWA SATOSHI
FUSE MASARU
International Classes:
H04L9/16; H04K1/02
Foreign References:
| JPH06104793A | 1994-04-15 |
Other References:
HIROTA O. ET AL.: "Quantum stream cipher based on optical communications", 8 July 2004 (2004-07-08), XP002996547, Retrieved from the Internet
NISHIOKA T. ET AL.: "Hikari Tsushin Ryoshi Ango no Anzensei (Security of Y-00 protocol)", 2004 NEN ANGO TO JOHO SECURITY SYMPOSIUM YOKOSHU (SCIS 2004), vol. 1 OF 2, 27 January 2004 (2004-01-27), pages 237 - 242, XP002996548
NISHIOKA T. ET AL.: "Hikari Tsushin Ryoshi Ango no Anzensei (Security of Y-00 protocol)", 2004 NEN ANGO TO JOHO SECURITY SYMPOSIUM YOKOSHU (SCIS 2004), vol. 1 OF 2, 27 January 2004 (2004-01-27), pages 237 - 242, XP002996548
Attorney, Agent or Firm:
Ogasawara, Shiro (13th Floor 1-23-101, Esakach, Suita-shi Osaka, JP)
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