Patent ID: 6807277
Filing Date: 2004-10-19
Classification: H04L

Abstract:
An electronic messaging system having a return receipt feature, the system comprising a sender computer, a server computer and a recipient computer, wherein:the sender computer is configured to send to the server computer, an issue request to have an encryption key issued; the server computer is configured to receive the issue request, issue a first encryption key and key retrieval information to the sender computer in response to the issue request, and store a first decryption key corresponding to the first encryption key in an associated memory whose location is referenced by said key retrieval information; the sender computer is further configured to encrypt a message using the first encryption key to thereby form an encrypted message, and send the encrypted message along with the key retrieval information to the recipient computer; the recipient computer is configured to receive the encrypted message and the key retrieval information, and send to the server computer a retrieval request including the key retrieval information to obtain the corresponding first decryption key; and the server computer is further configured to receive the retrieval request from the recipient computer, send to the recipient computer the corresponding first decryption key, as indicated by the key retrieval information sent by the recipient computer, and notify the sender computer that the corresponding first decryption key was retrieved by the recipient.