Data transfer system, data transfer program and video server system

A video server system comprising:

• a receiver for receiving a broadcast;
• a compressor which receives the broadcast from the receiver and generates compressed data of a size smaller than the broadcast;
• an encryptor which generates encrypted data by making a predetermined cryptographic key and by encrypting the broadcast with the cryptographic key;
• a first data storage device which stores the encrypted data;
• a decryptor;
• and
• a controller, and
• a second server, which includes a second data storage device, said second server being connected to the network, and storing compressed data and the cryptographic key on the second data storage device;
• wherein, in accordance with a first transfer command to transfer the broadcast from the first data storage device to the second data storage device, said controller controls the compressor to compress the broadcast on the first data storage device and pass the compressed data to the second data storage device, controls the encryptor to encrypt the broadcast on the first data storage device and send the encrypted data to the first data storage device and thereafter, gives the first data storage device a first erase instruction telling the first data storage device to erase the broadcast from itself, and
• wherein, in accordance with a second transfer command to restore the broadcast on the first data storage device, the controller controls the decryptor to decrypt the encrypted data on the first data storage device and thereafter gives the first data storage device a second erase instruction telling the first data storage device to erase the encrypted data from itself, and the second data storage a third erase instruction, telling the second data storage device to erase the compressed data and the cryptographic key from itself, respectively.

A computer program embodied in a computer readable media for transferring original data, which has been stored on a first data storage device, to a second data storage device, the program comprising the steps of:

• (a) receiving the original data from the first data storage device, generating compressed data of a size smaller than the original data, and passing the compressed data to the second data storage device;
• (b) making a predetermined cryptographic key and passing the key to the second data storage device;
• (c) receiving the original data from the first data storage device, encrypting the original data with the cryptographic key and sending the encrypted data back to the first data storage device;
• and
• (d) giving the first data storage device a first erase instruction, telling the first data storage device to erase the original data from itself;
• (e) receiving the encrypted data and the cryptographic key from the first and second data storage devices, respectively, and decoding the encrypted data with the cryptographic key;
• (f) sending the decrypted data back to the first data storage device;
• (g) giving the first data storage device a second erase instruction, telling the first data storage device to erase the encrypted data from itself;
• and
• (h) giving the second data storage device a third erase instruction, telling the secind data storage device to erase the compressed data and the cryptographic key from itself.