Invalidity dossier
US 7003667
Targeted secure printing
Current assignee: Canon Inc
Added 9/23/2026, 4:09:02 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US7003667B1
Title: Targeted secure printing
Assignee: Canon Inc. (original assignee); recorded assignment to CANON KABUSHIKI KAISHA on 1999-12-14.
Key dates: Priority/filing date 1999-10-04; granted and published 2006-02-21; anticipated expiration 2019-10-04. Legal status listed as "Expired – Fee Related." Inventors: Royce E. Slick, Craig Mazzagatte, Neil Y. Iwamoto. Application No. US09/411,070.
Purpose: To enable secure printing in a network where a print job may otherwise be intercepted—whether by network snooping or by someone viewing the document at the output device before the recipient arrives—so that an image can be generated only by an intended image output device in the presence of an intended recipient.
Plain-language scope: A randomly generated symmetric key encrypts the print data. That key is then encrypted twice with asymmetric (public/private key) algorithms: once with the public key of the intended image output device and once with the public key of the intended recipient. Both the encrypted data and the twice-encrypted key are sent to the output device. The key can only be recovered by decrypting with both private keys—the device's private key and the recipient's private key, with the recipient's private key personally supplied by the recipient. Because the symmetric key is needed to decrypt the print data, printing is confined to the intended device in the intended recipient's presence. The two encryptions may be performed in either order. The twice-encrypted key may be carried in a header with identity information.
Source: https://patents.google.com/patent/[US7003667](/patent/US7003667)/en
What the excerpt does not establish: The full claims, the complete written description, drawing content, all cited prior art, the exact scope of claim coverage (e.g., facsimile embodiments), and the reasons underlying the assignment or expiration status. Classifications listed include G06F21/608 (secure printing) and H04L9/0825.
Generated 10/1/2026, 9:51:05 PM
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Litigation summary
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Proceedings on file (0)
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PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.