Invalidity dossier
US 5485474
Scheme for information dispersal and reconstruction
Current assignee: Harvard University
Added 9/23/2026, 2:21:19 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 — US5485474A
Title: Scheme for information dispersal and reconstruction
Assignee: Harvard University (current and original assignee, per the listing)
Key dates:
- Prior art date / priority date: 1988-02-25 (priority stated as an assumption)
- Filing date: 1991-05-15
- Publication (grant) date: 1996-01-16
- Anticipated expiration: 2013-01-16
- Legal status: Expired – Lifetime (as listed)
Inventor: Michael O. Rabin
Purpose: The invention "relates to dispersal and reconstruction of information during communication or storage and retrieval, in order to achieve fault tolerance and load balancing." It addresses storing or transmitting information across portions or links prone to faults, where a fault in one portion does not necessarily imply a fault in another.
Plain-language scope: N characters of information are grouped into N/m groups of m characters, each treated as an element of a field or computational structure. A set of vectors (each with m coordinates) is selected so that any subset of m is very likely—up to certainly—linearly independent. Information is dispersed into n pieces, each nearly (or exactly) 1/m the size of the original and built from the vectors. Reconstruction uses any available m pieces: an m×m matrix of the corresponding vectors is formed and inverted, and the original characters are regenerated by multiplying the inverse matrix times groups of received elements, then reassembled. Applications include fault-tolerant storage media, communication links, distributed storage systems, and packet routing among nodes of a parallel computer. Fingerprints generated from pieces help reject bogus substitutions. The scheme claims space efficiency (n/m can approach 1) and computational efficiency across general-purpose, pipelined, systolic, and parallel/vectorized devices. The excerpt also states the invention features apparatus for performing these methods.
What the excerpt does not establish: The specific claims, their exact wording or numbering, the full detailed description, complete figure contents, the identity of cited prior art, and any legal conclusions about validity, enforceability, or ownership transfers. Litigation and assignment history are not addressed.
Source: https://patents.google.com/patent/[US5485474](/patent/US5485474)/en
Generated 10/1/2026, 9:52:21 PM
Cases on file (0)
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
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
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Obviousness
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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.