MESSAGE DOCUMENT SECURITY

摘要

A method of handling an electronic message created on a trusted or untrusted computer which is connected to a source network (1), wherein said message has a destination address which is not within said source network, comprises the steps of (a) directing messages having such a destination address to a trusted sealing device, (b) presenting the message to its author for visual checking and if acceptable to author associating the message with a seal produced by a trusted sealing device, (c) directing the message and associated seal to a gateway from said source network. Further steps comprise (d) receiving the message and associated seal at a gateway where there is a trusted verification means, and (e) checking the validity of the seal with said trusted verification means. And if and only if said seal is validly associated with said message, (f) directing the message and associated seal out of said source network.