Patent ID: 8281120
Filing Date: 2012-10-02
Classification: G06Q,H04L

Abstract:
1. A method for sending a signed e-mail message to a mail server from a device that communicates with the mail server over a network, the signed e-mail message having attachment data and signature data, said method comprising: receiving signer information, recipient information and attachment information; packaging the signer information, recipient information, and attachment information into an e-mail message having a clear-signed secure e-mail exchange format that includes an attachment body part and a signature body part, wherein the attachment body part contains the location of at least one attachment file included in the attachment information, and wherein the signature body part contains the signer information for generating the digital signature; creating an output data stream for streaming the e-mail message from the device to a mail server specified by the recipient information; processing the attachment body part to acquire at least one input data stream for the at least one attachment file location contained in the attachment body part; reading attachment data from the at least one input data stream; in response to receiving a portion of the attachment data from the at least one input data stream, digesting the received portion of the attachment data to generate a digest value, and sending the received portion of the attachment data to the mail server via the output data stream, wherein the received portion of the attachment data is smaller than the size of the attachment data, and wherein the digest value is updated as additional portions of the streamed attachment data are received and digested; and in response to sending all attachment data specified by the attachment information to the mail server, processing the signature body part to acquire a signer specified by the signer information contained in the signature body part, generating the signature data by using the signer to sign the digest value using a signer's private key, and sending the generated signature data to the mail server via the output data stream.