Hi,
I am not sure if this is the correct mailing list to post this query. I can appreciate anybody who can point me the right one, if this is not the one. After reading about random number generators I did some search in internet and learnt that all the software random number generators have a period. Even the blum blum shub and RSA have the period and that the sequence will repeat it self after some time though the time period is very long. I also read that it is possible to implement a random number generator with a period of the life time of the universe. But this also theoretically has a limit. What I want to know is, is there any algorithm that theoretically has no period. Thanks JB ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [hidden email] Automated List Manager [hidden email] |
Jagannadha Bhattu wrote:
>Hi, > >I am not sure if this is the correct mailing list to post this query. >I can appreciate anybody who can point me the right one, if this is >not the one. > > >After reading about random number generators I did some search in >internet and learnt that all the software random number generators >have a period. Even the blum blum shub and RSA have the period and >that the sequence will repeat it self after some time though the time >period is very long. I also read that it is possible to implement a >random number generator with a period of the life time of the >universe. But this also theoretically has a limit. What I want to know >is, is there any algorithm that theoretically has no period. > > If you use numbers with a finite size (which is the custom on current computers) you can easily (in theory) calculate the possible number of permutations, you'll find a period for every given sample size. Though usually you'll have to search for a VERY long time. Computers indeed are not built for eternity... ;) >[...] > > Hope it helps, Ted ;) -- PGP Public Key Information Download complete Key from http://www.convey.de/ted/tedkey_convey.asc Key fingerprint = 31B0 E029 BCF9 6605 DAC1 B2E1 0CC8 70F4 7AFB 8D26 smime.p7s (4K) Download Attachment |
In reply to this post by Jagannadha Bhattu
Of course all software RNG have their period! Because they are *P*RNG - PSEUDO random number generators. In other words - good enough for a limited time, and assuming that the adversary cannot get the seed. There can possibly be no software-based true RNG: if it is produced by an ALGORITHM, then it is DETERMINISTIC to begin with! As the same algorithm given the same input, would produce the same output - hardly "random".
RNG must be based on some physical effect, that itself is random. You can COLLECT randomness from various sources, such as zener diode noise, fluctuations of disk seek time, etc. So software can be a PART of an RNG (like the code that accesses and retrieves the data), but never - the source of random data. ----- Original Message ----- From: Jagannadha Bhattu <[hidden email]> Date: Friday, July 15, 2005 4:47 am Subject: Random number generator > Hi, > > I am not sure if this is the correct mailing list to post this query. > I can appreciate anybody who can point me the right one, if this is > not the one. > > > After reading about random number generators I did some search in > internet and learnt that all the software random number generators > have a period. Even the blum blum shub and RSA have the period and > that the sequence will repeat it self after some time though the time > period is very long. I also read that it is possible to implement a > random number generator with a period of the life time of the > universe. But this also theoretically has a limit. What I want to know > is, is there any algorithm that theoretically has no period. > > Thanks > JB > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List [hidden email] > Automated List Manager [hidden email] > OpenSSL Project http://www.openssl.org User Support Mailing List [hidden email] Automated List Manager [hidden email] |
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