A confidentiality system for ISDN inter-PC high-speed file transfer

We have developed a system enabling high-speed encrypted file transfer, while conducting secret voice communication using ISDN. The system will simultaneously encrypt and decrypt 1mbyte of plain text file on a hard disk and safely transfer the file to the disk of another party in about 2 min and 50 s, between any two PCs registered at the key distribution center. We developed a protocol for transmitting session keys from the key distribution center using UUI at the time of calling and making connection, to share session keys between the terminals at which communications are being conducted. Using this protocol adds about 1s to the normal time spent calling and establishing a connection, and represents a savings in communication costs.