Secure data transfer method

摘要

A method of transferring a file from a first to a second computer comprises the steps of encrypting the file on a first computer using an unique key code, authenticating to a third computer wherein a second user is selected and transmitting the file to the second computer. On receipt of the file the second user authenticates to the third computer and receives the key code to decrypt the file. The verification process uses a mask code applied to a pseudo-random string to create a volatile identification code. The verification is completed when the user code and a code generated by the third computer match. Entry of the mask code may be done through a designed interface which does not require special key presses. In a second embodiment the first computer undertakes the role of the third computer to verify a second user. In a third embodiment where a first computer downloads a file from a second computer, the verification method uses a telephone wherein the identification code is transmitted from the telephone to the second computer in response to a challenge issued on the first computer and if successful the second computer transmits the decryption key to the first computer.