Simtec Entropy key

For when you really need random numbers

The Entropy Key, or eKey, is a small, unobtrusive and easily installed USB stick that generates high-quality random numbers, or entropy, which can improve the performance, security and reliability of servers. It can also be used with scientific, gambling and lottery applications, or anywhere where good random numbers are needed. It has been developed by UK-based Simtec Electronics, a design consultancy and manufacturing partner with 20 years of experience in designing and building high-speed, high-performance electronics with a speciality in embedded ARM-based designs. It is currently undergoing testing with the help of selected customers.

The eKey contains two high-quality quantum noise generators, and an ARM Cortex CPU that actively measures, checks and confirms all generated random numbers, before encrypting them and sending them to the server. It also actively detects attempts to corrupt or sway the device. It aims towards FIPS-140-2 Level 3 compliance with some elements of Level 4, including tamper-evidence, tamper-proofing, role-based authentication, and environmental attacks. If it detects that one of its two generators has failed, may be about to fail, or if it detects a physical attack, it will automatically shut down.

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  1. So is this going to be offered through adafruit? I can’t find any purchasing information.

  2. @drake, all the information is on the page we linked to – we’re not carrying it, we just thought it was interesting.

  3. Drake, it would make a nifty kit, but this isnt our product 🙂 The noisiness from reverse-biasing zener diodes is well known in EE and its cool someone made a product from it

  4. I used something similar to this with one of my clients. It had an LCD and every time you logged into the server, you had to enter the number. I was told it was a random # generator that was based on the time? Very annoying, and probably not as secure as they thought it was.

  5. @marc –

  6. @ladyada: No zener diodes were harmed in the making of the Entropy Key.

    @marc: No, you’re thinking SecureID, which is an authentication gizmo that follows the “something you know, and something you have” mantra. The Entropy Key isn’t one of these; it is a random number generator for use by the system for all sorts of tasks (such as SSL and TLS transactions, certificate creation, PGP key creation, etc), rather than for humans logging in.

    We had a lot of fun making this; the CPU we used is wonderful for such small devices, and it’s really easy to get your own code going on it.

  7. @Rob, well, it does say PN junction, which is a diode. and one could classify any diode as a zener diode (albeit a very bad one) 😉
    is there anything special about the diode used?

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