Chaos cryptographic communication method and chaos cryptographic communication system

• US 7,054,446 B2
• Filed: 05/16/2001
• Issued: 05/30/2006
• Est. Priority Date: 05/17/2000
• Status: Expired due to Fees

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Abe, Takahiro, Ishihara, Tetsuya, Shono, Katsufusa
• Primary Examiner(s): Smithers, Matthew
• Assistant Examiner(s): FIELDS, COURTNEY D
• Application Number:
  US09/855,798
• Publication Number:
  US 20020009200A1
• Time in Patent Office: 1,840 Days
• Field of Search: 380/263, 380/37, 380/42
• US Class Current: 380/263
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 2209/84 Vehicles
• CPC Class Codes: H04L 9/001 using chaotic signals
• CPC Class Codes: H04L 9/0852 Quantum cryptography transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03

Abstract

Each of plural CPUs enciphers a plaintext code which is a secrecy object according to chaos block encryption and then enciphers it according to chaos stream encryption. Then, it transmits an obtained cipher code through communication line. On the other hand, each of plural CPUs that received the cipher code synchronously restores the received cipher code according to chaos stream encryption and then restores according to chaos block encryption thereby to obtain an original plaintext code.

Claims

1. A cryptographic communication method for use in cryptographic communication of information through communication lines among plural CPUs, the method comprising:

installing cryptographic algorithms containing a combination of chaos block encryption and chaos stream encryption in each of said plural CPUs;

deriving a cipher key, for carrying out cryptographic communication of information, from a data base; and

carrying out said cryptographic communication of information by applying said combination of chaos block encryption and said chaos stream encryption to the information.

4. A chaos cryptographic communication method as claimed in claim 1 wherein respective data bases for said cipher key, a cipher table and a restoration table in said chaos block encryption are controlled unitarily by providing with an appropriate initial value x(0).

2. A cryptographic communication system constructed by connecting plural CPUs through communication lines for carrying out cryptographic communication among the CPUs, wherein

said plural CPUs, after enciphering a plaintext code which is a secrecy object by chaos block encryption, encipher by chaos stream encryption and transmit an obtained cipher code, and

after synchronously restoring a received cipher code by said chaos stream encryption, restore by said chaos block encryption so as to obtain an original plaintext code.

5. A chaos cryptographic communication system as claimed in claim 2 wherein respective data bases for a cipher key, a cipher table and a restoration table in said chaos block encryption are controlled unitarily by providing with an appropriate initial value x(0).

3. A cryptographic communication system constructed by connecting plural CPUs through communication lines for carrying out cryptographic communication among the CPUs, wherein

said plural CPUs, after enciphering a plaintext code which is a secrecy object by chaos block encryption, encipher by chaos stream encryption and transmit an obtained cipher code, and

after synchronously restoring a received cipher code by said chaos stream encryption, verify a block cipher key and after it is certified that it is a legal access, restore by said chaos block encryption so as to obtain an original plaintext code.

6. A chaos cryptographic communication system as claimed in claim 3 wherein respective data bases for a cipher key, a cipher table and a restoration table in said chaos block encryption are controlled unitarily by providing with an appropriate initial value x(0).