creation of (real or pseudo) random numbers (or bits).
16
votes
4answers
668 views
How to fairly select a random number for a game without trusting a third party?
Several people are playing a game with random events and require a way to produce a random number. (Such as dice rolls or a lottery.)
Can this be done such that each player has the power to be ...
5
votes
2answers
320 views
creating a small number from a cryptographically secure random string
i'm trying to figure out the best way to generate a cryptographically secure random number between 0 and 200 from a cryptographically random string of bytes (ie. read from /dev/urandom or some such)
...
6
votes
2answers
1k views
Predicting values from a Linear Congruential Generator
I have learnt that Linear Congruential Random Number Generators are not cryptographically secure - my understanding is that given an LCG of the form:
...
6
votes
1answer
136 views
Correct way to map random number to defined range?
Say that we have a secure random number generation that outputs 32 bit random numbers, so it's output is a true random number between 0 and a MAX.
What is the best way to map this random number to a ...
9
votes
2answers
561 views
Blum Blum Shub vs. AES-CTR or other CSPRNGs
Following on from D.W.'s comments on a previous question, what properties does Blum Blum Shub have that make it better / worse than other PRNGs? Are there significant implementation difficulties or ...
8
votes
4answers
627 views
Properties of PRNG / Hashes
There are a lot of quite elaborate PRNG's out there (e.g. Mersenne Twister et.al.), and they have some important properties, especially when it comes to crypto applications.
So, I was wondering how ...
6
votes
3answers
401 views
What tests can I do to ensure my PRNG is working correctly?
In the past I have used the Chi-squared test to check the statistical randomness of my generator. Is this a good test to use? Are there other tests?
4
votes
3answers
251 views
Is there some way to generate a non-predictable random number in a decentralised network?
Is there a way to generate a random number with given restrictions:
It will be used in a decentralised network with a big number of peers (no central authority to generate it)
Its generation should ...
3
votes
2answers
198 views
Feedback on rolling my own entropy gatherer
First of all, I don't recommend doing this. This was something I created when I didn't know better and didn't have a solution available to me.
Long ago I created my own entropy gather for a ...
4
votes
2answers
913 views
Is the following statement about PRG true or false?
Is the following statement true?
If $G: \{0,1\}^k \rightarrow \{0,1\}^n$ is a PRG, then so is $G':\{0,1\}^{k+l} \rightarrow \{0,1\}^{n+l}$ defined as $$G'(x.x')=G(x).x'$$ where $x \in \{0,1\}^k$ and ...
3
votes
1answer
184 views
Are there secure stream ciphers that cannot be parallelized?
Are there any stream ciphers (or a deterministic random number generators, that should work as well I guess?) that cannot be parallelized?
So for example if I seed it with a specific value, and then ...
2
votes
2answers
238 views
Avalanche noise RNG for one-time pad use
I came across this little HRNG widget and was really intrigued as I have been looking for a decent but afordable source for truly random bits to use in a one-time pad.
The question is, would a HRNG ...
2
votes
3answers
230 views
PRNG taking advantage of very large seed
Can anyone suggest a good (CS)PRNG algorithm that takes advantage of having a very large (ideally arbitrarily large) seed? I'd like to use several kilobytes, perhaps several hundred kilobytes, of ...
1
vote
3answers
220 views
Entropy of system data - use all and hash, or trim least significant bits?
I'm working on a background entropy collector for key generation that monitors hardware and produces an entropy pool.
Here's my list of sources:
Mouse position
Keyboard timings (i.e. time between ...
