US 6,185,683 · Granted 2001-02-06

The 2001 Patent That Tried to Make Email as Trustworthy as a Sealed Letter

Before we had email signatures and encrypted attachments, Intertrust patented a way to deliver documents electronically with the same level of trust and proof as handing someone a paper document in person. The system could digitally 'sign' files, watermark them, and have a trusted middleman witness and archive everything—basically creating a secure digital mailroom.

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The plain-English version

What it protects

What's protected here is a system for delivering electronic documents and files through a 'trusted' intermediary that validates, witnesses, and archives the transaction. The claim covers marking documents with digital signatures, seal images, fingerprints, watermarks, or hidden data (steganography), plus the infrastructure of a reliable virtual distribution environment that records and verifies who sent what, when, and to whom. Anyone building a competing system that combines trusted intermediary validation with these marking and archival techniques would potentially infringe.

Why it matters

This patent arrived during the late 1990s when businesses were desperate for ways to execute contracts and exchange sensitive documents electronically without losing the legal weight of paper signatures and notarized seals. It staked out intellectual property around the concept of a 'trusted electronic witness'—a third party that could prove a transaction happened exactly as claimed. That idea became foundational to modern digital signature services, blockchain-based attestation, and enterprise document management systems, though the patent's specific claims may have narrowed over litigation and expiration.

Real-world use

When you sign a contract online using DocuSign or a similar e-signature platform, and it timestamps and records who signed when and from where, you're experiencing a modern descendant of the trusted delivery and archival system this patent outlined.

Original USPTO abstract

Documents and other items can be delivered electronically from sender to recipient with a level of trustedness approaching or exceeding that provided by a personal document courier. A trusted electronic go-between can validate, witness and/or archive transactions while, in some cases, actively participating in or directing the transaction. Printed or imaged documents can be marked using handwritten signature images, seal images, electronic fingerprinting, watermarking, and/or steganography. Electronic commercial transactions and transmissions take place in a reliable, “trusted” virtual distribution environment that provides significant efficiency and cost savings benefits to users in addition to providing an extremely high degree of confidence and trustedness. The systems and techniques have many uses including but not limited to secure document delivery, execution of legal documents, and electronic data interchange (EDI).

Patent details

Publication number: US 6,185,683
Filing date: 1998-12-28
Grant date: 2001-02-06
Assignee: Intertrust Technologies Corp.
Inventor(s): GINTER KARL L., SHEAR VICTOR H., SPAHN FRANCIS J., VAN WIE DAVID M., WEBER ROBERT P.
CPC class: G06Q50/184

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