Tadashi Kaji

This inventor holds 23 USPTO granted patents and 14 published patent applications, plus 1 CIPO patent and 5 EPO patents, primarily in Encrypted Communication. Top assignee: Hitachi, Ltd.. Active years: 2001-2026.

IDiyas Innovation Intelligence. (2026). Inventor Profile: Tadashi Kaji. Retrieved from https://idiyas.com/inventor/tadashi-kaji

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

USPTO Granted Patents = 23 (Patent Applications = 14)

% Patents Active = 8.7

CIPO Patents = 1

EPO Patents = 5 (Patent Applications = 9)

Average Co-Inventor Count = 4.8

ph-index = 6

Forward Citations = 105(Granted Patents)

Location History:

Fujisawa, JP (2001 - 2013)
Yokohama, JP (2008 - 2013)
Tokyo, JE (2016)

Company Filing History:

23 out of 42,726

Hitachi, Ltd.

patents

Years Active: 2001-2026

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Areas of Expertise:

Data Circulation Control

Vulnerability Countermeasure

Public-Key Certificate Validation

Encrypted Communication

Communication Status Management

Key Allocation System

Digital Document Exchange

Authentication Infrastructure

Cryptographic Communication

Data Communication System

Service Network System

Printer Selection Assistance

23 patents (USPTO):Sort by Forward CitationsExplore Patents

1. 12563040 - Data circulation control method, data circulation control system, and approval server (2026-02-24),

2. 9372995 - Vulnerability countermeasure device and vulnerability countermeasure method (2016-06-21),

3. 8516245 - Method, product and apparatus for accelerating public-key certificate validation (2013-08-20),

4. 8402524 - ID bridge service system and method thereof (2013-03-19),

5. 8238555 - Management server, communication apparatus and program implementing key allocation system for encrypted communication (2012-08-07),

6. 8218769 - Encrypted communication system, communication status management server, encrypted communication method, and communication status management method (2012-07-10),

7. 8205074 - Data communication method and data communication system (2012-06-19),

8. 8095676 - Mediating system and method to establish communication session, allowing private information to be protected (2012-01-10),

9. 8094337 - Device and system for assisting printer selection through a network (2012-01-10),

10. 8081758 - Communication support server, communication support method, and communication support system (2011-12-20),

11. 8041822 - Service network system and server device (2011-10-18),

12. 8019996 - Method for encrypted communication with a computer system and system therefor (2011-09-13),

13. 8010793 - Data communication method and system (2011-08-30),

14. 7984290 - System and method for encrypted communication (2011-07-19),

15. 7940780 - Data communication system enabling data communication between communication devices through a server (2011-05-10),

Title: Innovations and Contributions of Tadashi Kaji

Introduction

Tadashi Kaji is a prominent inventor based in Yokohama, Japan, known for his innovative contributions in the field of computer security and public-key certificate validation. With a remarkable portfolio of 22 patents, Kaji has made significant advancements that enhance the safety and efficiency of networked computing systems.

Latest Patents

Among his latest patents are two notable innovations: a vulnerability countermeasure device and a vulnerability countermeasure method. The vulnerability countermeasure device is designed to store configuration information that connects multiple computers within a network. It effectively assesses vulnerabilities in software and executes countermeasure policies. This invention calculates the specific computer where data will reach based on its routing information, acquires the software present, and determines its vulnerability based on established information.

Additionally, Kaji holds a patent for a method, product, and apparatus aimed at accelerating public-key certificate validation. This patent introduces a validation authority that periodically searches for and verifies certificate paths and revocation lists. By classifying these paths, it registers valid and invalid paths in databases, greatly improving the efficiency of certificate validity requests.

Career Highlights

Tadashi Kaji is currently employed at Hitachi Ltd., a multinational company recognized for its technological advancements and innovations. His work at Hitachi has allowed him to collaborate on impactful projects that strengthen cybersecurity measures across various sectors.

Collaborations

Kaji frequently collaborates with esteemed colleagues such as Takahiro Fujishiro and Kazuyoshi Hoshino. Together, they contribute to the ongoing development of advanced technologies within their fields, fostering a collaborative environment that promotes innovation and research.

Conclusion

Tadashi Kaji exemplifies the spirit of innovation with his extensive contributions to cybersecurity and software vulnerability assessments. His patents not only reflect his dedication to advancing technology but also serve as a testament to his impact on enhancing the safety and efficiency of networked systems.

Profile summary based on public USPTO records.