Disclosed is a total system for preventing an online and off-line leakage of information, which includes a security maintenance client having a program storing a file in a storing device and a file security control part which encodes the file content to be stored in the storing device and stores a log information, and security maintenance server which receives the log information and a decoding key and decodes the encoded file. The security maintenance client further includes a communication security control part which has a communication program transmitting a file and encodes the file content to be transmitted to a transmission destination of a network and stores a log information. The security maintenance server further includes an automatic key transmission part which receives a decoding key to be transmitted to the transmission destination according to a file transmission security policy after receiving the log information and the transmission destination.