DECODING APPARATUS IN DATA ENCRYPTION SYSTEM, ENCRYPTION DEVICE, ENCRYPTED DATA DECODING METHOD, AND STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a data encryption system adopting a public key encryption system that eliminates the need for storage of a private key to a storage medium. SOLUTION: A data acquisition means 1 acquires received data acting like a seed to generate a pair of public and private keys. A key pair generating means 2 generates a key pair uniquely corresponding to data being the seed. A public key transmission means 3 transmits the public key in a pair of the generated keys to a decoder. A data re-acquisition control means 4 controls the key pair generating means 2 to acquire the data being the seed for generating a key pair newly every time receiving encrypted data generated by using the received public key. A key pair reproduction control means 5 controls the key pair generating section 2 to generate a key pair from the data that are newly acquired and act like the seed. A decoding means 6 uses the private key in the key pair generated by the key pair generating control means 5 under the control of the key pair generating means 2 to decode the encryption data.