A few days ago I ordered a small batch of +the ChaosKey, 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:
+ ++ ++% 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 +% +
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:
+ ++ ++% 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 +% +
Quite the difference. :) I bought a few more than I need, in case +someone want to buy one her in Norway. :)
+
