| 主权项 |
1. A communication system, comprising:
a sender unit; a recipient unit; and a control unit, wherein each of the sender unit, the recipient unit and the control unit comprises at least one of the group consisting of a server computer comprising a memory element, a client computer, a desktop computer, a laptop computer, a personal digital assistant, and a mobile phone; wherein the sender unit, the recipient unit and the control unit being communicatively coupled via a communication network; wherein the sender unit is adapted to generate an electronic message to be transmitted to the recipient unit and to send a sending information message to the control unit indicating that the electronic message is transmitted to the recipient unit; wherein the sender unit is adapted for mandatorily attaching a predetermined attachment to the electronic message, the predetermined attachment having a particular extension allowing a software installed on the recipient unit to automatically determine the type of message; wherein the recipient unit is adapted to receive the electronic message and to send a receipt information message to the control unit, the receipt information message indicating that a user of the recipient unit has received the electronic message and that the electronic message comprises the predetermined attachment; wherein the sender unit is adapted to generate the electronic message as an encrypted electronic message by encrypting electronic data; wherein the sender unit is adapted to generate a fingerprint of the electronic message, the fingerprint allowing for unambiguous identification of the electronic message, and to send the fingerprint to the control unit; wherein the sender unit is adapted to send a decryption key to the control unit as at least a part of the sending information message, the decryption key being adapted to decrypt the encrypted electronic message; wherein the recipient unit is adapted to generate a fingerprint of the electronic message, the fingerprint allowing for unambiguous identification of the electronic message, and to send the fingerprint to the control unit; wherein the control unit is adapted to compare the fingerprint generated by the recipient unit and the fingerprint generated by the sender unit; wherein the control unit is adapted to trigger sending of the correct decryption key to the recipient unit only upon positive match of the fingerprints; and wherein the control unit is adapted for rejecting delivering of the correct decryption key when the predetermined attachment to the electronic message is missing. |
