Communication system for encrypted data and apparatus for selectively recording and reproducing received analog signal and received digital signal

• US 6,363,210 B1
• Filed: 03/17/1999
• Issued: 03/26/2002
• Est. Priority Date: 08/26/1994
• Status: Expired due to Term

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Tachibana, Hiroaki, Sugimura, Naozumi, Hosokawa, Kyoichi, Okamoto, Hiroo, Yoshizawa, Kazuhiko, Owashi, Hitoaki, Hayakawa, Hiroyuki, Amada, Nobutaka, Noguchi, Takaharu
• Primary Examiner(s): TRAN, THAI Q
• Application Number:
  US09/270,766
• Time in Patent Office: 1,105 Days
• Field of Search: H04/N.576, H04/N.592, 380/4-5, 380/9-10, 380/21, 380/23, 380/25, 380/273, 380/277-286, 380/44-47, 340/825.31, 340/825.34, 360/60, 386/94-95, 705/71, 713/171
• US Class Current: 386/259
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: G11B 15/125 conditioned by the operating function of the apparatus
• CPC Class Codes: G11B 15/1875 adaptations for special effects or editing signal processing or indexing therefor G11B27/00
• CPC Class Codes: G11B 15/4671 by controlling simultaneously the speed of the tape and the speed of the rotating head
• CPC Class Codes: G11B 5/0086 using cyclically driven heads providing segmented tracks
• CPC Class Codes: G11B 5/00878 transducing different track configurations or formats on the same tape
• CPC Class Codes: G11B 5/09 Digital recording
• CPC Class Codes: G11B 5/531 Disposition of more than one recording or reproducing head on support rotating cyclically around an axis
• CPC Class Codes: G11B 5/534 inclined relative to the direction of movement of the tape, e.g. for helicoidal scanning
• CPC Class Codes: H04N 5/775 between a recording apparatus and a television receiver
• CPC Class Codes: H04N 9/7921 for more than one processing mode
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

A communication system has an analog signal broadcasting station for transmitting an analog signal, a digital signal broadcasting station for transmitting a digital signal and a receiving unit for receiving the analog signal from the analog signal broadcasting station and the digital signal from the digital signal broadcasting station. The receiving unit has a recording and reproducing unit for selectively recording one of received analog and digital signals. The recording and reproducing unit has heads for analog signal each having a predetermined azimuth angle and operative to record an analog signal and heads for digital signal each having an azimuth angle larger than that of the analog signal head and operative to record a digital signal, and performs selective recording and reproduction of the analog signal and the digital signal on and from a recording medium.

Claims

1. An apparatus for transmission of encrypted data comprising:

a memory for storing a plurality of customer identifying codes and arithmetic formulas set for individual customers;

means for reproducing data requested for transmission by a customer;

means for reading a customer identifying code and an arithmetic formula of the customer requesting transmission and generating an initial value;

means for operating the initial value pursuant to said read-out arithmetic formula to calculate a key signal;

encrypting means for encrypting data from said reproducing means on the basis of the key signal from said calculating means to generate main data to be transmitted; and

means for multiplying said main data with said initial value and said customer identifying code and transmitting a resulting signal.

2. The transmitting apparatus according to claim 1, wherein said reproducing means is means for reproducing a plurality of pieces of data requested for transmission by a plurality of customers, said apparatus further comprising:

compression means for compressing and coding said plurality of pieces of data reproduced from said reproducing means; and

means for time-division multiplexing coded data from said compression means,

said encryption means being means for encrypting a time-division multiplexed signal from said time-division multiplexing means.

3. A receiving unit for receiving main data transmitted from the transmitting apparatus as recited in claim 1, said receiving unit comprising:

means for receiving multiplexed data transmitted from said transmitting apparatus;

receiving demultiplexing means for demultiplexing said multiplexed data received by receiving means to provide said main data, said initial value and said customer identifying code;

receiving unit memory for storing an identifying code and an arithmetic formula which are identical to those of this customer stored in said memory of said transmitting apparatus;

arithmetic means for confirming reception of data requested for transmission by this customer by collating said customer identifying code with said identifying code in said receiving unit memory and operating said demultiplexed initial value pursuant to said arithmetic formula in said receiving unit memory to calculate a key signal;

recording and reproducing unit for recording and reproducing said main data; and

first decryption means for decrypting said main data on the basis of the key signal calculated by said arithmetic means to provide said data requested for transmission.

4. The receiving unit according to claim 3 further comprising an IC card including said receiving unit memory and said arithmetic means and detachably mounted to a main body of said receiving unit.

5. The receiving unit according to claim 3 further comprising:

means for encrypting the key signal calculated by said arithmetic means by using the identifying code from said receiving unit memory; and

means for multiplexing the key signal encrypted by said encryption means and main data from said receiving demultiplexing means,

said recording and reproducing unit being means for recording data multiplexed by said multiplexing means.

6. The receiving unit according to claim 5 further comprising:

means for demultiplexing multiplexed data reproduced from said recording and reproducing unit into said main data and said encrypted key signal; and

second decryption means for decrypting said encrypted key signal from said demultiplexing means on the basis of said identifying code to provide said key signal.

7. The receiving unit according to claim 3, wherein said recording and reproducing unit records said initial value and said main data, said arithmetic means is means for providing said key signal by operating said initial value reproduced from said recording and reproducing unit pursuant to said arithmetic formula read out of said receiving unit memory, and said main data reproduced from said recording and reproducing unit is decrypted on the basis of said key signal calculated by said arithmetic means.

8. An apparatus for recording at least encrypted main data and a key signal decrypting said encrypted main data, comprising:

a memory for storing an identifying code which identifies an individual customer, and an arithmetic algorithm set for said individual customer;

an arithmetic circuit for calculating the key signal by using said arithmetic algorithm, and an encryption circuit for encrypting the key signal by using said identifying code;

a multiplexing circuit for multiplexing said encrypted main data and said encrypted key signal; and

a recording circuit for recording said encrypted main data and said encrypted key signal multiplexed by said multiplexer circuit.

9. An apparatus for reproducing at least encrypted main data and an encrypted key signal decrypting said encrypted main data, from a storage medium,

said storage medium containing a key calculated by an arithmetic algorithm that is specific to an individual customer, and encrypted by using an identifying code specific to the individual customer, and further containing main data that have been encrypted using the key, said apparatus comprising:

a demultiplexing circuit for demultiplexing said encrypted key signal from reproduced data;

a memory for storing said identifying code that is specific to said individual customer;

a first decryption circuit for decrypting said encrypted key signal demultiplexed by said demultiplexing circuit by using said identifying code; and

a second decryption circuit for decrypting said encrypted main data by using said key signal calculated by said arithmetic algorithm, which key signal has been decrypted by said first decryption circuit.

10. An apparatus for transmitting at least encrypted main data and a key signal decrypting said encrypted main data, comprising:

a memory for storing an identifying code which identifies an individual customer, and an arithmetic algorithm set for said individual customer;

an arithmetic circuit for calculating the key signal by using said arithmetic algorithm, and an encryption circuit for encrypting the key signal by using said identifying code;

a multiplexing circuit for multiplexing said encrypted main data and said encrypted key signal; and

an output circuit for delivering said encrypted main data and said encrypted key signal multiplexed by said multiplexing circuit.

11. An apparatus for receiving transmitted data containing at least encrypted main data multiplexed with an encrypted key signal decrypting said encrypted main data,

said transmitted data containing a key calculated by an arithmetic algorithm that is specific to an individual customer, and encrypted by using an identifying code specific to the individual customer, and further containing main data that have been encrypted using the key, said apparatus comprising:

a demultiplexing circuit for demultiplexing said encrypted key signal from received data;

a memory for storing said identifying code that is specific to said individual customer;

a first decryption circuit for decrypting said encrypted key signal demultiplexed by said demultiplexing circuit by using said identifying code; and

a second decryption circuit for decrypting said encrypted main data by using said key signal calculated by said arithmetic algorithm, which key signal has been decrypted by said first decryption circuit.