A signing interface is disclosed for facilitating digital signing of
electronic messages by a buyer or other subscribing party in an
e-commerce or other context. The signing interface provides a mechanism
by which a seller's Web applications may invoke a buyer's smartcard
subsystem or other signing module to execute a digital signature. The
signing interface preferably comprises a signing interface library and a
signing plug-in resident on the buyer's computer. The signing interface
library is preferably implemented as a Java package and associated
libraries that are installed locally on the buyer's computer and made
accessible to signed Java applets provided by the seller's Web server.
The signing plug-in is preferably implemented as a plug-in, ActiveX
control, or similar code that is installed locally on the buyer's
computer and made accessible through the buyer's Web browser using an
embedded browser object on a seller's Web page. In a preferred
embodiment, the signing interface may be adapted to facilitate access to
system services such as a warranty service provided via a four-corner
trust model.