Internet & Cryptography Patents

Filed in the U.S. on May 21, 1970, granted on January 23, 1973, expired on January 23, 1990 (Lifetime). Mario W. Cardullo and William L. Parks III, working at Communications Services Corporation (Rockville, Maryland), jointly invented the foundational RFID patent US3713148A 'Transponder Apparatus and System.' Claim 1 defines a 'self-contained transponder with writable memory powered by the interrogation signal itself.' Claim 4 extends the carrier wave to light frequency, Claim 5 to acoustic frequency. The Description explicitly cites 'automatic highway toll device for motor vehicles' as a sample application — the conceptual ancestor of ETC, written 31 years before Japan's ETC launched in 2001. 185 forward citations. Read this as the precursor to apartment key fobs, employee badges (HID Prox), Walmart inventory tags, pet ID chips, and the NFC tag inside an Apple TechWoven Case. Title, full Claim 1, inventors, filing/grant/expiration dates, Abstract, and forward citation count retrieved from Google Patents. **The DB record (candidates.tsv) attributing this to 'Charles Walton' is wrong** — Walton was a separate RFID pioneer; he is not an inventor on this patent.

Filed in the U.S. on May 21, 1970; granted January 23, 1973. Communications Services Corporation obtained the RFID (radio frequency identification) ancestor patent US3713148A, 'Transponder apparatus and system.' Inventors are Mario W. Cardullo and William L. Parks III — **two co-inventors** (the 'Charles Walton' entry in the local DB belongs to a separate patent line and is not on this patent). Claim 1 describes a transponder system with 'changeable memory,' 'self-powering from the interrogation signal,' and 'read/write control.' More than 50 years after grant in 1973, read this as the precursor to Suica, PASMO, NFC payment, electronic passports, retail anti-theft tags, and livestock microchips. Basic info, Claim 1 summary, inventors, filing/grant dates, and Abstract retrieved from Google Patents. Full description and comparison to Charles Walton's patents not yet checked.

Filed in the U.S. on October 17, 1986; granted February 13, 1990. Qualcomm Inc obtained the CDMA core patent US4901307A, 'Spread spectrum multiple access communication system using satellite or terrestrial repeaters.' Inventors are Klein S. Gilhousen, Irwin M. Jacobs, and Lindsay A. Weaver, Jr. — **three co-inventors** (Andrew Viterbi, listed in the local DB, is not on this patent). Claim 1 defines a 'spread spectrum multiple access communication system through satellite or terrestrial repeaters' and lays the design skeleton that connects to IS-95 (cdmaOne) → CDMA2000 → 3G WCDMA. Read this as the precursor to 3G/4G/5G. Basic info, Claim 1 summary, inventors, filing/grant dates, and Abstract retrieved from Google Patents. Full description and Viterbi-related patents not yet checked.

Filed in the U.S. on September 17, 1997; granted July 8, 2003; expired August 15, 2018. Jaap Haartsen (Jacobus Cornelis Haartsen) of Ericsson is registered as the **sole inventor** on the Bluetooth core patent US6590928B1, 'Frequency hopping piconets in an uncoordinated wireless multi-user system.' Claim 1 defines a wireless network of master and slave units, in which a virtual frequency hopping channel is derived from the master address and master clock. Multiple piconets coexist without synchronizing with each other (uncoordinated). Read this as the precursor to AirPods, Magic Mouse, hearing aids, Apple Watch, fitness bands, and smart locks. Title, full Claim 1, inventor, filing date, priority date, grant date, abstract, and current assignee retrieved from Google Patents.

Filed August 1995 by Netscape Communications, US5657390A 'Secure socket layer application program apparatus and method' was invented by Taher Elgamal and Kipp E. B. Hickman. It describes a socket API that places a security protocol between the application layer and the transport layer. The body uses 'Secure Sockets Layer,' 'SSL library,' and 'SSL protocol' multiple times. Expired in the U.S. (Lifetime). Current Assignee is Meta Platforms Inc — a curious twist of corporate history. Read this as the precursor to HTTPS, TLS 1.3, HSTS, and QUIC/HTTP3. Title, Abstract, Claim 1 outline, inventors, dates, and Legal Status retrieved from Google Patents; full text and the chain of correspondences with later TLS RFCs not yet read.

Filed October 1986, US4698672A 'Coding system for reducing redundancy' was issued to Compression Labs (CLI), invented by Wen-Hsiung Chen and Daniel J. Klenke. The text says it is 'particularly useful in video compression systems' and never once uses the word 'JPEG.' Yet in 2002, Forgent Networks — which had inherited the patent through corporate transfers — claimed JPEG images infringed it and demanded license fees from companies across the web. Expired in the U.S. on October 27, 2006. Read this as a precursor to WebP, AVIF, HEIC, and to the rise of patent-pool governance. Title, Abstract, Claim 1 outline, inventors, dates, and Legal Status retrieved from Google Patents; full text and Forgent litigation primary sources not yet read.

Filed in the U.S. on March 14, 1995, with priority from Japanese application JP4258794A (March 14, 1994), Toyota Central R&D Labs and NipponDenso jointly received US5726435A 'Optically readable two-dimensional code and method and apparatus using the same.' Three position-detecting symbols (finder patterns) are placed so that any scan line passing through a symbol's center returns the same black:white:black:white:black = 1:1:3:1:1 ratio, regardless of direction. Expired in the U.S. on March 14, 2015. Not Hara's solo invention — five co-inventors. The decisive design choice was Denso Wave's later policy: hold the patent but make the spec royalty-free. Read this as the precursor to PayPay, airline boarding QRs, and vaccination certificates. Title, Claim 1, inventors, filing/priority dates, and Abstract retrieved from Google Patents.

Filed November 1993, US5487069 'Wireless LAN' by O'Sullivan and four co-inventors at Australia's CSIRO describes multi-subchannel modulation (effectively OFDM) for practical data transmission in indoor multipath environments at frequencies above 10 GHz. Later asserted as a standard-essential patent on IEEE 802.11a/g/n/ac, drawing more than $430M in cumulative settlements from 14 Wi-Fi equipment makers worldwide. Title, gist of Claim 1, inventors, filing date, and Legal Status retrieved from Google Patents. Full Description and litigation primary sources not yet read.

Filed September 1977, US4200770A 'Cryptographic apparatus and method' by Hellman, Diffie, and Merkle at Stanford. Built on the computational hardness of the discrete logarithm problem, it patented a way for two parties to derive a shared secret key over an insecure channel without any prior shared secret. Expired in the U.S. in 1997. The ancestor of TLS/HTTPS, Signal, WireGuard, and SSH handshakes. Title, Claim 1, and the Y₁^X₂ mod q = Y₂^X₁ mod q description retrieved from Google Patents. Full Description text and related litigation primary sources not yet read.

Filed January 1995 in the U.S. with priority from German DE3912605 (April 1989), Fraunhofer's US5579430 'Digital encoding process' captures the heart of MP3: spectral transform, variable-precision quantization, and a variable-length code where 'the more frequent the spectral coefficient, the shorter the code word.' Not the single MP3 patent — one core piece of ISO/IEC 11172-3 Layer 3. U.S. expired 2013; Fraunhofer's licensing program ended in 2017. A precursor to Spotify, Apple Music, Podcasts, and Discord audio. Title, Claim 1, inventors, filing/priority dates, and Abstract retrieved from Google Patents.

Filed March 1975, US4063220A by Metcalfe, Boggs, Thacker, and Lampson at Xerox PARC describes 3 Mbps packet communication over coaxial cable using CSMA/CD (carrier sensing + collision detection + randomized backoff). A precursor to modern Ethernet, Wi-Fi, data center networks, and cloud infrastructure. Primary source URL confirmed; Claim 1, CSMA/CD details, and 3 Mbps speed retrieved; full text not yet read.

Filed October 1995, US5774670A by Lou Montulli at Netscape describes 'persistent client state' — what we now call cookies — as the answer to HTTP statelessness. The patent specifies the Set-Cookie header syntax, domain/path matching, and the secure flag. Later assigned to Meta Platforms via Netscape's asset acquisition. A reading aid for understanding modern Cookie regulations, third-party Cookie deprecation, and the design difference vs. JWT/OAuth. Primary source URL confirmed; Claim 1 retrieved; full text not yet read.

Filed October 1949, US2612994A by Woodland and Silver describes a 'classifying apparatus' that identifies articles using concentric circular light-reflective lines and photoelectric scanning. Not linear, not laser-based — the original barcode was circular and read by a photocell. A precursor to modern UPC, QR codes, RFID, and supply-chain identification. Expired 1969. Title, Claim 1, inventors, and filing data retrieved from Google Patents.