EP0999488A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Self-protecting documents
Assignee: Contentguard Holdings Inc
•
Filing: 1999-10-22
•
Granted: —
•
Expires: 2019-10-22
Abstract
Abstract A system and method for the secure distribution of electronic documents reduces the likelihood of unauthorized reproduction and redistribution by either authorized or unauthorized recipients. A self-protecting document (SPD) contains an encrypted document as well as a secure set of permissions and the software necessary to process the document; full decryption of the document is performed as late as possible so as to minimize the possibility of intercepting the document before it has been fully rendered to screen or to paper.
Inventors
- 👤 Prasad Ram
- 👤 Thanh T. Ta
- 👤 Xin Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 19:55
CPC Classifications
G; G06; G06F; G06F21/00; G06F21/60; G06F21/62; G06F21/6209; G06F21/10; G06F21/106; G06F21/1063; G06F21/107; G06F21/16; G06F2221/00; G06F2221/21; G06F2221/2141; G06F2221/2151
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
33 words
A self-protecting document embodied as data stored on a
tangible storage medium, the self-protecting document comprising: an encrypted content segment containing data representative of
document contents; a permissions segment; and a code segment.
Claim 2
Dependent Claim
18 words
The self-protecting document of claim 1, wherein the code
segment comprises: a rights-enforcement subsection; and a rendering subsection.
Claim 3
Dependent Claim
15 words
The self-protecting document of claim 1, wherein the code
segment further comprises a polarization subsection.
Claim 4
Dependent Claim
18 words
The self-protecting document of claim 3, wherein the
polarization subsection comprises a polarization engine and a depolarization
engine.
Claim 5
Dependent Claim
21 words
The self-protecting document of claim 1, wherein the
polarization subsection contains executable computer code adapted to
modify the encrypted content segment.
Claim 6
Dependent Claim
26 words
The self-protecting document of claim 1, wherein the
polarization subsection contains executable computer code adapted to
modify the encrypted content segment into a polarized content segment.
Claim 7
Independent Claim
52 words
A method for creating a self-protecting document, comprising
the steps of: receiving an unencrypted document; modifying the unencrypted document to produce an original content
segment; creating a rights specification; creating a code segment; and combining the original content segment, the rights specification, and
the code segment to produce a generic self-protecting document.
Claim 8
Dependent Claim
17 words
The method of claim 7, wherein the modifying step comprises
the step of encrypting the unencrypted document.
Claim 9
Independent Claim
78 words
A method for using a self-protecting document having an
encrypted content segment on a user's system, comprising the steps of: obtaining a polarization key; modifying the encrypted content segment with the polarization key to
produce to produce polarized content; rendering the polarized content to produce rendered polarized content
for output on an output device; depolarizing the rendered polarized content with the polarization key
to produce rendered clear content; and sending the rendered clear content to the output device.
Claim 10
Dependent Claim
31 words
The method of claim 9, wherein the step of modifying the
encrypted content segment comprises the substep of transforming the
encrypted content segment via an encryption algorithm employing the
polarization key.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.