H04K 1/04
Secret communication: by frequency scrambling, i.e. by transposing or inverting parts of
Official title: by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band
H04K1/04 (Secret communication: by frequency scrambling, i.e. by transposing or inverting parts of) appears on 119 US grants and 77 published applications in this corpus.
Search patents in H04K- Granted patents
- 119
- Published applications
- 77
- Assignees
- 81
- Inventors
- 262
- Latest grant
- 26 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 2 | 0 |
| 1978 | 1 | 0 |
| 1979 | 1 | 0 |
| 1980 | 2 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 1 | 0 |
| 1988 | 3 | 0 |
| 1989 | 4 | 0 |
| 1990 | 3 | 0 |
| 1991 | 3 | 0 |
| 1992 | 2 | 0 |
| 1993 | 1 | 0 |
| 1994 | 2 | 0 |
| 1995 | 3 | 0 |
| 1996 | 2 | 0 |
| 1997 | 0 | 0 |
| 1998 | 3 | 0 |
| 1999 | 2 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 0 | 1 |
| 2003 | 1 | 2 |
| 2004 | 1 | 2 |
| 2005 | 1 | 4 |
| 2006 | 0 | 0 |
| 2007 | 1 | 1 |
| 2008 | 2 | 1 |
| 2009 | 1 | 2 |
| 2010 | 3 | 3 |
| 2011 | 2 | 4 |
| 2012 | 3 | 3 |
| 2013 | 4 | 1 |
| 2014 | 4 | 1 |
| 2015 | 2 | 2 |
| 2016 | 4 | 2 |
| 2017 | 2 | 4 |
| 2018 | 0 | 2 |
| 2019 | 5 | 4 |
| 2020 | 8 | 10 |
| 2021 | 8 | 8 |
| 2022 | 5 | 9 |
| 2023 | 7 | 3 |
| 2024 | 4 | 3 |
| 2025 | 3 | 3 |
| 2026 | 3 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Communications system to adjust a signal scrambler26 May 2026US 12,640,833 B2Intel Corporation
- Acoustic pattern determination5 May 2026US 12,620,401 B2Hewlett-Packard Development Company, L. P.
- System and method for secure processing of speech signals using pseudo-speech representations20 Jan 2026US 12,531,051 B2Microsoft Technology Licensing, LLC
- Operating method of electronic apparatus for transmitting signal and electronic apparatus supporting the same2 Dec 2025US 12,489,543 B2Agency for Defense Development
- Signal modification for control channel physical layer security18 Mar 2025US 12,256,214 B2QUALCOMM Incorporated
- System and method for secure processing of speech signals using pseudo-speech representations16 Apr 2026US 2026/0105907 A1Microsoft Technology Licensing, LLC
- Expendable Active Decoy5 Feb 2026US 2026/0036408 A1Embraer S.A.
- Signal modification for control channel physical layer security19 Jun 2025US 2025/0203354 A1QUALCOMM Incorporated
- Multi-access point (multi-ap) joint transmission in a wireless network17 Apr 2025US 2025/0126641 A1Newracom, Inc.
- Method for designing interference noise of speech based on the human speech structure6 Mar 2025US 2025/0078843 A1ZJU-Hangzhou Global Scientific and Technological Innovation Center
Most cited
By later US patents
- Fourier masking analog signal secure communication system90US 4,393,276 ABell Telephone Laboratories, Incorporated · 1983
- Deterrence of device counterfeiting, cloning, and subversion by substitution using hardware fingerprinting50US 8,848,905 B1Sandia Corporation · 2014
- Analog scrambling with continuous synchronization49US 5,278,907 ATranscrypt International, Inc. · 1994
- Communications system with tandem scrambling devices48US 4,914,696 AMotorola, Inc. · 1990
- Speech component coded multiplex carrier wave transmission45US 3,991,273 ABell Telephone Laboratories, Incorporated · 1976