- <item>
- <title>Unlimited randomness with the ChaosKey?</title>
- <link>http://people.skolelinux.org/pere/blog/Unlimited_randomness_with_the_ChaosKey_.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Unlimited_randomness_with_the_ChaosKey_.html</guid>
- <pubDate>Wed, 1 Mar 2017 20:50:00 +0100</pubDate>
- <description><p>A few days ago I ordered a small batch of
-<a href="http://altusmetrum.org/ChaosKey/">the ChaosKey</a>, a small
-USB dongle for generating entropy created by Bdale Garbee and Keith
-Packard. Yesterday it arrived, and I am very happy to report that it
-work great! According to its designers, to get it to work out of the
-box, you need the Linux kernel version 4.1 or later. I tested on a
-Debian Stretch machine (kernel version 4.9), and there it worked just
-fine, increasing the available entropy very quickly. I wrote a small
-test oneliner to test. It first print the current entropy level,
-drain /dev/random, and then print the entropy level for five seconds.
-Here is the situation without the ChaosKey inserted:</p>
-
-<blockquote><pre>
-% cat /proc/sys/kernel/random/entropy_avail; \
- dd bs=1M if=/dev/random of=/dev/null count=1; \
- for n in $(seq 1 5); do \
- cat /proc/sys/kernel/random/entropy_avail; \
- sleep 1; \
- done
-300
-0+1 oppføringer inn
-0+1 oppføringer ut
-28 byte kopiert, 0,000264565 s, 106 kB/s
-4
-8
-12
-17
-21
-%
-</pre></blockquote>
-
-<p>The entropy level increases by 3-4 every second. In such case any
-application requiring random bits (like a HTTPS enabled web server)
-will halt and wait for more entrpy. And here is the situation with
-the ChaosKey inserted:</p>
-
-<blockquote><pre>
-% cat /proc/sys/kernel/random/entropy_avail; \
- dd bs=1M if=/dev/random of=/dev/null count=1; \
- for n in $(seq 1 5); do \
- cat /proc/sys/kernel/random/entropy_avail; \
- sleep 1; \
- done
-1079
-0+1 oppføringer inn
-0+1 oppføringer ut
-104 byte kopiert, 0,000487647 s, 213 kB/s
-433
-1028
-1031
-1035
-1038
-%
-</pre></blockquote>
-
-<p>Quite the difference. :) I bought a few more than I need, in case
-someone want to buy one here in Norway. :)</p>
-
-<p>Update: The dongle was presented at Debconf last year. You might
-find <a href="https://debconf16.debconf.org/talks/94/">the talk
-recording illuminating</a>. It explains exactly what the source of
-randomness is, if you are unable to spot it from the schema drawing
-available from the ChaosKey web site linked at the start of this blog
-post.</p>
-</description>
- </item>
-