Title:
ENCRYPTED DATA RECEPTION DEVICE AND DECRYPTION KEY UPDATING METHOD
Document Type and Number:
WIPO Patent Application WO/2004/105308
Kind Code:
A1
Abstract:
A reception device and a decryption key updating method for encrypted data such as DTCP standard capable of eliminating the update timing difference of a public key NC between a data reception device and a data transmission device at an early stage without increasing the enquiry packet amount between the devices. An inspection section checks whether a decryption has been successful according to the fixed information arranged at a predetermined bit position of the decrypted data. If an inspection result indicating data decryption failure is output continuously by a predetermined number of times, a judgment section outputs a judgment signal indicating that updating of the decryption key following the updating of the encryption key of the data transmission device has failed and a calculation section updates the decryption key according to the judgment signal.
Inventors:
KOSAKI MAKOTO (JP)
Application Number:
PCT/JP2003/006436
Publication Date:
December 02, 2004
Filing Date:
May 22, 2003
Export Citation:
Assignee:
FUJITSU LTD (JP)
KOSAKI MAKOTO (JP)
KOSAKI MAKOTO (JP)
International Classes:
G03C7/392; H04L9/08; H04N7/167; H04N7/24; H04Q7/38; G03C1/005; G03C7/396; (IPC1-7): H04L9/08; G09C1/00; H04L9/14
Foreign References:
| JP2000228059A | 2000-08-15 | |||
| JPH0563142A | 1993-03-12 | |||
| JPH06164630A | 1994-06-10 | |||
| JP2000332743A | 2000-11-30 | |||
| JP2002247542A | 2002-08-30 |
Attorney, Agent or Firm:
Yamanaka, Ikuo (Nagoya Center Building 2-22, Nishiki 2-chome, Naka-k, Nagoya-shi Aichi, JP)
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