[Japanese patent Number] 2002-366030
[NAME] Hierarchical encryption methods for various data and media
[Inventor] Tetsuya Takahashi
[Owners]
FIT Corporation and FusionSys Corporation

HES (Hierarchical Encryption System) is a common-key-based encryption method. Main characteristics of HES:

* HES was invented in Japan.
* It is possible to stream-wise encrypt data.
* It is possible to make a master key.
* It is possible to encrypt data hierarchically.

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[Japanese patent number] 2003-404537
[Name] A method and a system for managing electrical contents and a program implementing the method and the system

[Inventors] Tadashi Syouji and Tetsuya Takahashi
[Owners] FIT Corporation and FusionSys Corporation