Cryptographic key, encryption device, encryption/decryption device, cryptographic key management device, and decryption device

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.

1 - 7 . (canceled)  
   
   
       8 . An encryption/decryption device for encrypting and decrypting plaintext data by use of a cipher key, the encryption/decryption device comprising: 
 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.    
   
   
       9 . The encryption/decryption device according to  claim 8 , 
 wherein the first external device executes an exclusive-OR operation for the pseudo random number obtained by the pseudo random number generator in the first cryptographic key and the plaintext data to encrypt the plaintext data, and    the second external device executes an exclusive-OR operation for the pseudo random number obtained by the pseudo random number generator in the second cryptographic key and the cryptographic data to decrypt the cryptographic data.    
   
   
       10 . The encryption/decryption device according to  claim 8 , 
 wherein the first cryptographic key stores a first password in advance,    the second cryptographic key stores a second password in advance,    the first external device collates a password inputted from a first input unit and the first password stored in the first cryptographic key, and permits an encryption processing when both of the passwords coincide with each other, and    the second external device collates a password inputted from a second input unit and the second password stored in the second cryptographic key, and permits a decryption processing when both of the passwords coincide with each other.    
   
   
       11 - 17 . (canceled)