Patent ID: 8369587

Claim:
A digital signature system, comprising: an Electronic Data Interchange (EDI) server; and a portable terminal communicating with the EDI server, comprising: a touch-sensitive display; and a processing unit, comprising: a receiving module configured for receiving a file from the EDI server; a signature mode control module configured for providing a signature file mode and a non-signature file mode for users to selected; a signature file creating module configured for signature input through the touch-sensitive display and creating a signature file to record the input signature if the signature file mode is selected; a non-signature file creating module configured for recognizing signature input through the touch-sensitive display, converting the input signature to recognizable characters, and creating a non-signature file to record the characters if the non-signature file mode is selected; and a file combining module configured for combining the signature file and the file from the EDI server to a composite signature file, and combining the non-signature file and the file from the EDI server to a composite non-signature file.