DATA TRANSFER METHOD AND SYSTEM

PROBLEM TO BE SOLVED: To provide a data transfer system in which the ciphertext generated by using a security module can be decrypted even by a computer not possessing a function to encrypt/decrypt the data. SOLUTION: The data cryptographic equipment 1 divides the plaintext which is the data to be encrypted successively from the top into a block of a predetermined size within a security module 10 provided with a function to internally store a cipher key in confidentiality for encrypting data and encrypts the plaintext in a block unit. The data cryptographic equipment 2 stores the cipher table generated in the security module 10, divides the ciphertext successively from the top into the block of the same size as that of the plaintext, and decrypts the ciphertext in the block unit by referring to the cipher table, thereby generating the plaintext of the ciphertext. COPYRIGHT: (C)2008,JPO&INPIT