Abstract: An electronic data storage system stores electronic data with attaching an electronic signature, and output the electronic data along with the attached electronic signature, which decreases the operation costs with a simple operation. By using a public key-based signature, a third party can verify the data, and by using a secret check code, the electronic signature at registration is always valid without risk of falsification. Also by attaching an electronic signature at access, the validity of the stored data is assured, and a third party can verify the data. By using all of these features, the verification by a third party becomes possible over the long term. In this way the long term storage of electronic data is implemented.

Abstract: An electronic data storage system stores electronic data with attaching an electronic signature, and output the electronic data along with the attached electronic signature, which decreases the operation costs with a simple operation. By using a public key-based signature, a third party can verify the data, and by using a secret check code, the electronic signature at registration is always valid without risk of falsification. Also by attaching an electronic signature at access, the validity of the stored data is assured, and a third party can verify the data. By using all of these features, the verification by a third party becomes possible over the long term. In this way the long term storage of electronic data is implemented.

Abstract: The encryption processing apparatus includes a plurality of encryption processing units each of which executes an encryption processing. One encryption processing unit generates a key, encrypts the key, and delivers the encrypted key to the other encryption processing units. Each of the other encryption processing units decodes the received key and stores the key so that the keys stored in all the encryption processing units is same.

Abstract: The memory backup device obtains power from four power supply systems having different voltages. These power supply systems are selectively employed based on their voltages. In operating, backup is performed by an internal battery as a first power supply system, or by power from a mainframe apparatus as a third or fourth power supply system. When the electronic device is to be stocked in a warehouse, only then, an external battery is connected as a second power supply system.