In message <[email protected]> on Tue, 24 Apr 2018 19:24:40 +0200, Kurt Roeckx <[email protected]> said:
kurt> On Tue, Apr 24, 2018 at 07:20:42AM +0200, Richard Levitte wrote: kurt> > Like I think I mentioned a few days ago, I'm currently on a conference. I'll take this up in more depth later this week. kurt> > kurt> > I have a question, though... Kurt said at some point that all that was needed on the VMS side was to collect data, the rest can be done elsewhere (thankfully). However, I don't really understand what the collected data is supposed to be. Just the same stream of bytes that I would feed the entropy acquisition, or something else? Is the time delta between samples a factor in this? kurt> kurt> The API support getting data that has 1 bit of entropy per 128 bit kurt> received (DRBG_MINMAX_FACTOR). If it's worse than that, you might kurt> have to write your own extract method. I might have to either way, don't I. A method I'm pondering is to pass all the data gathered (700-something bytes) through sha512 and add the result to the pool. I have no idea what that says about the entropy of the original data, which is at somewhere between 0.1 and 0.2 entropy bits per data bit according the 3rd order entropy calculation that I replicated from the Linux /dev/urandom driver. kurt> A stream of bytes it just fine. kurt> kurt> I think the tme delta will really depend on your source. If it kurt> really changes all the time, it really doesn't matter much how kurt> fast you do it. But I think some (most?) of the variables don't kurt> change that often. It doesn't change *all* the time, but with a 1-10 second sleep between data gatherings, there's always *something* that has changed enough to give a 3rd order diff from previous sampling that's > 0. So what I've done for now is to make two files, one that's the raw data, repeatedly gathered every 1-10 seconds until I got about 1 Mib of data, the other being a concatenation of sha512 calculations of those same (*) data until I filled that file up to 1 Mib. I suspect that the latter isn't quite valid, considering Paul said something about no transformation whatsoever, but I thought it would be worth a try. I'll have to try and feed this to the entropy test programs you indicated earlier... Cheers, Richard -- Richard Levitte [email protected] OpenSSL Project http://www.openssl.org/~levitte/ _______________________________________________ openssl-project mailing list [email protected] https://mta.openssl.org/mailman/listinfo/openssl-project
