Questions tagged [random-number-generator]
A random number generator is a software or hardware solution which functions as a generator of (real or pseudo) random numbers (or bits).
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questions
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Is random.org truly reliable?
Can someone help me in gaining an understanding of the reliability of random.org being used by a University to select student applicants to extend invitations to?
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1answer
44 views
Is it possible to create a 128-bit UUID from a weak entropy source?
I am looking at a seemingly popular piece of JavaScript code to generate a UUID which is supposed to be a 128-bit number:
...
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2answers
123 views
What's the name of this random number generation algorithm?
I'm looking for the name of an RNG method or algorithm, described below. Combining multiple results of a non-uniform random number generator can produce a more uniform result. It seems like this would ...
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0answers
79 views
RNG to hide some bits
Suppose I have a sequence of bits of length M. I need to hide N out of M bits (hiding means forcing them to be 0) using RNG with a key. How I can relate the output of RNG to the number and positions ...
2
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1answer
63 views
Breaking a Mersenne-twister RNG with unsequential outputs
Pardon me for this newbie-ish question. I'm still a novice in cryptography . I have an application that outputs random numbers from 0 - 12 (endpoints inclusive) unsequentially (some outputs are thrown ...
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0answers
58 views
CSPRNG for Contract Bridge (RAND_MAX = 0xAD55E315634DDA658BF49200)
Some background information:
In contract bridge, there are 0xAD55E315634DDA658BF49200 (just under 2^96) possible bridge deals. Since the 1990s, bridge deals for major tournaments were generated on ...
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0answers
35 views
Understanding a claim made by NIST SP 800-22 on the possibility of calculating $\beta$, the probability of error type 2 in a hypothesis test
NIST SP 800-22 on page 1-4 (that's page 16 of the PDF) states the following. Pay attention to the bold passages. (Emphasis are mine.) Are they true?! Can you advise?
One of the primary goals of ...
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5answers
6k views
Can I encrypt a message by swapping bits in the text?
I have tried out an encryption method, in which I swap bits in the text.
The text length is N bit, then I generate several random number pairs in the range 0..N-1, as [n,k] pairs. After that I swap ...
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1answer
477 views
Practical sources of entropy on an Android device?
What Android API's can be used a practical sources of entropy ?
Given the requirement of sourcing entropy on the phone for purposes of seeding a PRNG, what are good options ?
Edit:
I have a hard ...
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1answer
67 views
How many 12 bit integers output are required to reverse the Mersenne Twister?
I am creating a web app that applies Python's random algorithm (Mersenne Twister) to generate random 12-bit integers. I am concerned as to how a user can predict ...
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1answer
74 views
Would knowing the random seed help to break AES or similar?
Consider I knew the seed of the random number generator that Bob uses to send encrypted emails to Alice. Would I have an advantage in deciphering the message? Also, how does, for example, openssl ...
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1answer
14 views
Allowing third party to verify and/or replay a draw
I’m not an expert in crypto, and I would like to design draw system (like a lottery, but choosing one of the participants), the most open possible, allowing a third party to verify the data/draws, and ...
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0answers
24 views
When will the random bit sequence start to repeat in pseudo random number generator
Let's say we have the Blum-Micali pseudorandom number generator.
from wikipedia:
Let $p$ be an odd prime, and let $g$ be a primitive root modulo $p$.
Let $x_0$ be a seed, and let $x_{i+1} = g^{x_i}\ ...
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2answers
55 views
Extracting Randomness from a Poisson Distribution
I'm working on a quantum random number generator based on the shot noise of CMOS camera sensor. Shot noise in an image is caused by the variance of the number of photons hitting the sensor per unit of ...
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1answer
509 views
Is it possible to construct a PRNG where the output numbers have a certain distribution of hamming weights?
I am in need of a non-uniform random number generator where each n-bit output has a hamming weight with a certain binomial distribution.
For example, I would like a non-uniform PRNG which generates ...
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1answer
96 views
Is it possible to predict a randomly generated BigInteger that uses Java's default Random library?
I've seen it posted on different forms here and here that explain how java.util.Random library uses a linear congruential pseudorandom number generator which can be ...
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1answer
83 views
Randomness extractors from Bourgain’s breakthrough- applications?
Some exciting progress to pure mathematics is due to Bourgain
Springer - Multilinear Exponential Sums in Prime Fields Under Optimal Entropy Condition on the Sources
with applications to randomness ...
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0answers
38 views
Linear approximattion of $(x+y) \bmod 2^n$ in FSM of SNOW 2.0 where $x,y$ in $F_{2}^n$
I would like to understand the linear approximation of $(x+y) \bmod 2^n$ by linear masking method in the paper refereed ""Improved Linear Distinguis'hers for SNOW 2.0" by Kaisa Nyberg and Johan Wall´...
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1answer
85 views
Pseudorandom number generation predictability
Can you expect with certainty that any pseudo-random number generator will produce the same stream with a shared seed?
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1answer
83 views
Construct a specific length-doubling pseudorandom generator from a length-doubling pseudorandom
Let $G$ be a length-doubling pseudorandom generator (i.e., for any $n\in \mathbb{N}$ and for
any $s\in\{0, 1\}^n$ it holds that $G(s)\in\{0, 1\}^{2n}$). Can you construct a length-doubling ...
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3answers
99 views
Why can a symmetric encryption algorithm be considered a pseudo-random number generation algorithm?
I have a question from my teacher: "Why can a symmetric encryption algorithm be considered a pseudo-random number generation algorithm?
Can anyone explain it to me?
And sorry if my english is not ...
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2answers
4k views
A website that identifies an RNG from its output
This happened during a discussion of RNG entropy, and the difficulty of verifying the level of entropy in a long sequence of bits (e.g. a private key.)
A colleague of mine told me about a website ...
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1answer
75 views
If ChaCha20 is being used just as a CSPRNG, is nonce needed?
I'm planning to use ChaCha20 just as a CSPRNG. Key is random (taken from strong initial entropy source) and will be constantly replaced via DJB's fast key-erasure scheme. What should I use as the ...
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2answers
350 views
Why is Math.floor(Math.random()*9000) not secure in JavaScript?
I heard that one can predict the output from Math.Random() of JavaScript, but another day I had an idea to combine Math.random() ...
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1answer
139 views
How to get the original list back given a shuffled list and seed?
Say I have a shuffled list that was shuffled in Python using random.shuffle(). The shuffling was performed using a seeded random number generator. Is there a way I ...
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1answer
753 views
RFC6979: error in reference implementation?
If I correctly understand RFC 6979, there is an error in the ref implementation section 3.2.
In the step H2, RFC specification says
...
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2answers
806 views
How to analyze the off-by-one error's impact on the entropy of the result?
I'm reading Jean-Philippe Aumasson's book Serious Cryptography to learn more about cryptography. On page 37, the author gives an example of Cryptocat's off-by-one error in its PRNG implementation in ...
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1answer
86 views
Mathematical proof or any reference of “Deterministic random bit generator cannot produce more randomness than the randomness of seed”
The heading tells everything. Any proof or any kind of reference is welcome regarding this:
Can we get more randomness from a deterministic random bit generator than the entropy that we feed to the ...
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1answer
115 views
Murder Mystery Party
For a "Murder Mystery Party", one person is chosen anonymously to be the murderer
(i.e., only the murderer knows who the murderer is) by shuffling cards with
everyone randomly taking a private card (...
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1answer
112 views
Dieharder input file with a sequence of only binary numbers
I have a RNG producing sequences of binary numbers, ad I would like to run Dieharder test using them as an ascii txt input file. However I haven't been able to do it properly. Should I use a header ...
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2answers
86 views
Mathematical definition of deterministic and non-deterministic random bit generators
Can anyone give the mathematical definition of deterministic and non-deterministic random bit generator?
Providing a reference will also be very helpful.
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2answers
86 views
Doesn't d6 to binary for 256-bit bitcoin private key generation produce biased results?
If the mapping table looks like:
1: 000
2: 001
3: 010
4: 011
5: 100
6: 101
Then you are guaranteed that your key will never have a chain of 4 or more 1s, much fewer chains of 3 ones than would ...
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1answer
132 views
Distance between consecutive primes distribution
In several prime generation schemes I saw we pick a random number uniformly at random from a wide range and find the next prime after it.
Obviously with such a scheme some primes are more likely than ...
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1answer
103 views
Can a PRNG be made into a CSPRNG by hashing the outputs?
So I was contemplating this answer to my last question, and it got me thinking:
If I understand it right, one of the required properties of a CSPRNG is that it resists leaking information about its ...
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1answer
133 views
Is the PCG PRNG a CSPRNG, or why not?
Is the PCG family of PRNG algorithms cryptographically secure, and if not, what about them makes them inadequate for that?
I have a good enough understanding of the general problem space that if you ...
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1answer
64 views
Faster Shuffling for a Simple Application
Alice, Bob, and Charlie are working on three projects.
Alice is the manager. At the beginning of each day, she chooses one
project to work on (this choice is based on her preferences and is
not ...
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0answers
35 views
NIST Approved Entropy Source List
Per NIST SP 800-90B – Section 3 – Entropy Source Validation : This Recommendation provides requirements for validating an entropy source at a stated entropy rate. Validation consists of testing by an ...
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1answer
66 views
Min Entropy Value for Health Test per NIST 800-90B for 32 bit Noise Source
NIST 800-90B recommends Section 4.4.1 Repetition Count Test & Adaptive Proportion Test for health test on Noise sources.
In the equation to calculate the cut-off value C for Repetition Count Test,...
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2answers
104 views
PRNG next bit test
I would like to know whether a specific PRNG satisfy the next-bit test or not.
will satisfying all of NIST statistical tests on PRNG guarantees passing the next-bit test? Or is there a specific ...
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1answer
25 views
Does concatinating mutliple digests of hashes from CSRN result in a CSRN?
Kind of a noob question. Suppose;
We generate 1,000 cryptographic-ally secure random numbers & store each of them in an array1.
For each number in this array1, we take the hash sha256(CSRN) then ...
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4answers
10k views
The GCD strikes back to RSA in 2019 - Good randomness is the only solution?
When someone collects lots of RSA public modulus, the first thing comes to mind is;
$$\text{GCD them all}$$
If you calculate the GCD of two different RSA modulus and if the result is not 1 then you ...
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2answers
742 views
Perfect shuffle possible with limited raw entropy?
I am trying to shuffle a standard 52-card deck in a perfect way (every outcome should be possible at an equal chance). I am not, at this point, concerned with cryptanalysis attacks against it.
I have ...
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2answers
218 views
The importance of randomness in the creation of a key
Why does it matter what kind of random number generation is used during key generation?
E.g. this answer states ...
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1answer
83 views
Creating Random Pad from XORed Sections of Pi
If two strings of equal length from random offsets in Pi were XORed together, would this result in a cryptographically secure random number suitable for use in a one-time pad? If so, would this mean ...
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1answer
79 views
PRNG XOR Pipeline
For an OTP I need the 'best' random data I can acquire.
Please check if my thinking for stacking PRNGs together in a pipeline can only make the output statistically better, never worse?!
So take a ...
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3answers
117 views
Should the seed of CSPRNG produce the same random number?
Assume we are designing a CSPRNG to be used in encryption like that used for ECC-based cryptography.
Is it required that the seed always produces the same random number always? Or should it be ...
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1answer
89 views
What is the weakpoint of PRNG based encryption? [closed]
Let's say I used this encryption schema:
In words instead of images:
Hash the encryption key with SHA256
Split it in half, first half use as XOR key for first 128 bit block of plaintext
Hash the ...
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1answer
127 views
Is it possible to recover the seed value from a Mersenne Twister PRNG state?
So I know that you can recover the state of a mersenne twister generator by observing a sequence which is long enough.
I was wondering if you could be able to recover the actual seed value used or ...
2
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1answer
118 views
Strong RNG for encryption/authentation algo
I saw in the market several hardware options for creating strong RNG to produce strong KEYS:
HSM
TPM internal TRNG
Intel RDSEED (TRNG)/RDRAND
My questions are;
What is the strength/entropy ...
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0answers
44 views
using non prime numbers in Blum Blum Shub or Blum Micali
I would like to use Blum Blum Shub, or Blum Micali methods as random number generators only. I am not interested in their encryption capabilities.
I was wondering, if I replaced the prime numbers ...
