1. More Entropy, Please

    This was originally a story written to my imaginary/sworn(?) elder sister and her daughter in Singapore.

    It began with "Hello, ..., It's long time since..."

    NOTE: In this article, we discuss a possible side channel attack (of gniibe). Although we discuss the vulnerability by an …

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  2. A 64-bit computer^Wcalculator design

    In my public key cryptography project, this is deadly needed: non-electrical manual computer^Wcalculator, so that I can manually compute digital signature.

    Here is a figure to show the basic design of its register of 64-bit.

    +-----------------------------------------------+
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    |<> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>|
    |<> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>|
    |                                               |
    |-----------------------------------------------|
    |                                               |
    |<> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>|
    |<> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>|
    |<> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>|
    +-----------------------------------------------+
    

    It's 3-3 abacus. You may know that Japanese abacus adopts 1-4 system, while Chinese …

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  3. Flying Stone Mini 55 Test Plan

    We need to specify the test plan to manufacture the board. In order to encourage designing and manufacturing by yourselves, we show our test plan for Flying Stone Mini 55 here.

    As of August 2014, free software tool to program MCU's flash ROM is not yet ready (for reset signal …

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  4. Flying Stone Mini 55 and its purpose

    The purpose of FSM-55 is to encourage more people to join development of free software and free hardware design.

    Its features are intentionally (quite) limited, so that people can design their own boards by themselves.

    The experience around FST-01

    We developed FST-01 in 2011 and we have been selling since …

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