Cryptographic key, encryption device, encryption/decryption device, cryptographic key management device, and decryption device
First Claim
1. A cryptographic key constituted to be freely attachable and detachable to/from an external device encrypting and decrypting data by use of a cipher key, the cryptographic key comprising:
- a pseudo random number generator for generating a pseudo random number of a chaotic time series based on a data size of the data, a chaotic function and ail initial value of the chaotic function; and
a transmission/reception control unit for receiving the data size of the data from the external device and transmitting the pseudo random number of the chaotic time series as the cipher key to the external device, the pseudo random number being generated in the pseudo random number generator, when the cryptographic key is attached to the external device.
2 Assignments
0 Petitions
Accused Products
Abstract
A cryptographic key 1 constituted to be freely attachable and detachable to/from a personal computer 2 encrypting and decrypting data by use of a cipher key includes: a pseudo random number generator 14 for generating a pseudo random number of a chaotic time series based on a data size of the data, a chaotic function and an initial value of the chaotic function; and a USB controller 12 for receiving the data size of the data from the personal computer 2 and transmitting the pseudo random number of the chaotic time series as the cipher key to the personal computer 2, the pseudo random number being generated in the pseudo random number generator 14, when the cryptographic key 1 is attached to the personal computer 2.
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Citations
17 Claims
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1. A cryptographic key constituted to be freely attachable and detachable to/from an external device encrypting and decrypting data by use of a cipher key, the cryptographic key comprising:
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a pseudo random number generator for generating a pseudo random number of a chaotic time series based on a data size of the data, a chaotic function and ail initial value of the chaotic function; and
a transmission/reception control unit for receiving the data size of the data from the external device and transmitting the pseudo random number of the chaotic time series as the cipher key to the external device, the pseudo random number being generated in the pseudo random number generator, when the cryptographic key is attached to the external device. - View Dependent Claims (2, 3, 4)
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5. An encryption device for encrypting plaintext data by use of a cipher key, the encryption device comprising:
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a cryptographic key having a pseudo random number generator for generating a pseudo random number of a chaotic time series based on a data size of the plaintext data, a chaotic function and an initial value of the chaotic function; and
an external device for transmitting the data size of the plaintext data to the cryptographic key upon being equipped with the cryptographic key, and for encrypting the plaintext data by use of the pseudo random number of the chaotic time series as the cipher key, the pseudo random number being sent from the cryptographic key. - View Dependent Claims (6, 7)
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8. An encryption/decryption device for encrypting and decrypting plaintext data by use of a cipher key, the encryption/decryption device comprising:
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a first cryptographic key having a pseudo random number generator for generating a pseudo random number of a chaotic time series based on a data size of the plaintext data, a chaotic function and an initial value of the chaotic function;
a second cryptographic key having a same constitution as the first cryptographic key;
a first external device for transmitting the data size of the plaintext data to the first cryptographic key upon being equipped with the first cryptographic key, and for encrypting the plaintext data by use of the pseudo random number of the chaotic time series from the first cryptographic key as the cipher key to create cryptographic data; and
a second external device for receiving the cryptographic data from the first external device, for transmitting a data size of the cryptographic data to the second cryptographic key upon being equipped with the second cryptographic key, and for decrypting the cryptographic data by use of the pseudo random number of the chaotic time series from the second cryptographic key as the cipher key. - View Dependent Claims (9, 10)
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11. A cryptographic key management device for managing a cryptographic key constituted to be freely attachable and detachable to/from an external device,
wherein the cryptographic key includes: -
a pseudo random number generator for generating a pseudo random number of a chaotic time series based on a data size of data, a chaotic function and an initial value of the chaotic function;
a transmission/reception control unit for receiving the data size of the data from the external device upon being attached to the external device, and for transmitting the pseudo random number of the chaotic time series as the cipher key to the external device, the pseudo random number being generated in the pseudo random number generator; and
a memory having a program area for storing a program, an update password for indicating permission and refusal of update of the program of the program area, and a program update area for storing the update program, the external device includes;
a password deletion unit for sending out a delete command to the cryptographic key to delete the update password therefrom when updating the program of the program area in the memory; and
a transmission unit for transmitting the update program in a unit of a predetermined length to the cryptographic key after deleting the update password, and the cryptographic key turns into an update mode by the deletion of the update password, and stores the update program from the external device in the unit of the predetermined length in the program update area, then transports the update program in the unit of the predetermined length to the program area, the update program being stored in the program update area. - View Dependent Claims (12, 13)
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14. A cryptographic key management device for managing a cryptographic key constituted to be freely attachable and detachable to/from an external device,
wherein the external device includes; -
an initial value table storing a cryptographic key number and an initial value of a chaotic function for each cryptographic key, the cryptographic key number and the initial value being made to correspond to each other; and
a transmission unit for reading out the initial value corresponding to the cryptographic key number from the initial value table to transmit the initial value to the cryptographic key when the cryptographic key is attached to the external device, and the cryptographic key includes;
a memory for storing the initial value from the external device; and
a pseudo random number generator for generating a pseudo random number of a chaotic time series based on the initial value stored in the memory, a data size of data and the chaotic function. - View Dependent Claims (15)
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16. A decryption device for decrypting cryptographic data by use of a cryptographic key constituted to be freely attachable and detachable to/from an external device,
wherein the external device includes: -
a cryptographic file storing the cryptographic data and a group password inherent in a plurality of users capable of using the cryptographic data;
a transmission unit for transmitting the group password and a data size of the cryptographic data to the cryptographic key when an inputted coincides with the group password stored in the cryptographic file; and
a decryption unit for decrypting the cryptographic data in the cryptographic file by use of a cipher key from the cryptographic key, and the cryptographic key includes;
a pseudo random number generator for generating a pseudo random number of a chaotic time series based on the data size of the cryptographic data from the external device, a chaotic function and the group password as an initial value of the chaotic function; and
a transmission/reception control unit for receiving the group password and the data size of the cryptographic data from the external device, and for transmitting the pseudo random number of the chaotic time series as the cipher key to the external device, the pseudo random number being generated in the pseudo random number generator. - View Dependent Claims (17)
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Specification