3 ms·
> /dev/random will still block after reading a few bytes. Have you tried Haveged? http://www.issihosts.com/haveged/ http://www.issihosts.com/haveged/
by bungle 13y ago
> /dev/random will still block after reading a few bytes.
Have you tried Haveged?
http://www.issihosts.com/haveged/ http://www.issihosts.com/haveged/
- JoachimS 13y agoHavege and other CPU-based entropy sources are interesting. But they do implicit assumptions such as that the TSC is somehow giving you real measurements (and is not virtualized for example) and that the CPU has cache memories, do out-of-order issue etc which makes the exection time variable. We have tested Havege and on modern x86 systems you do get good numbers. But there are embedded SSL stacks that use Havege on such things as AVR32 cpus where the exection time is much more predictable. I have yet to test in those environments, but it does not look like a smart move. Also, Havege includes an entropy estimator that seems to be broken. We used the Simics system simulator and forced the TSC to be stuck and could see that we got bad entropy from Havege. But the estimator happily said that the entropy was good. My suggestion is that if you are to use Havege and friends, use them to feed the OS entropy pool, not as a replacement for /dev/random, /dev/uramndom. And speaking of friends. Jytter is one such friend. I have yet to test it with Dieharder though. http://jytter.blogspot.se/ http://jytter.blogspot.se/
- JoachimS 13y agoI have now tried Jytter on OSX (MBA with Ivy Bridge Core i7). I get about 50 kbps from jytter. Testing the data with Dieharder I get about 82% success rate on the test cases.