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).
684
questions
2
votes
1answer
68 views
Cryptography Engineering - Design Principles and Practical Applications - Chapter 9 Generating Randomness - Section 9.4 The Generator
I'm currently reading "Cryptography Engineering - Design Principles and Practical Applications" written by "Niels Ferguson, Bruce Schneier, Tadayoshi Kohno" published by Wiley in ...
1
vote
2answers
74 views
Using raw encrypted network data for randomness
I've read that encrypted data should be, theoretically, indistinguishable from random data. Using this principle of encryption, could I combine encrypted network traffic streams to generate either a ...
7
votes
4answers
2k views
Radioactive Decay, Gaussian or Uniform?
I'm trying to understand the nature of true randomness. I'm building an RNG using a radioactive source. Basically, I'm measuring the time between consecutive decays which in theory should be ...
1
vote
1answer
37 views
Can you explain to me how permuted congruential generator XSL-RR-RR works?
I found note about XSL-RR-RR on wikipedia:
https://en.wikipedia.org/wiki/Permuted_congruential_generator
But I don't understand what this means:
count = (int)(x >> 122)
low64 = rotr64((uint64_t)...
1
vote
0answers
44 views
Min Entropy per Bit for Trevisan's Extractor/or An Extractor
We know that: trevisan's extractor based on min entropy of the relative system. For trevisan extractor, we need source, seed, min entropy value per bit and error rate for per bit
I have the code for ...
2
votes
1answer
32 views
Differences between Extractors and Privacy Amplification for Quantum Random Generators
We know that for the last step of QRNG: we need to separate quantum and classical noises from each other so we use extractors, after extractor we need privacy amplification step. At this point: if ...
1
vote
1answer
110 views
Dieharder How can I make my input file suitable for Dieharder?
I created my random numbers and I saved them into a txt file. My input file includes just 0 and 1. Here is the link of my file
And I of course read some answer before asking that question but I could ...
4
votes
1answer
68 views
Does piping MT19937 random stream into SHA512 make the state of MT unrecoverable in practice?
It's well known that state of a Mersenne twister is quite easy to recover after you observe enough samples. But what happens if we pipe blocks comming out of MT into SHA512 and give this as output.
...
1
vote
1answer
70 views
Is a stream cipher and a (cryptographically secure) PRNG nearly the same thing?
If I let the authentification tag aside (which is important), encrypting with AES-GCM and a fixed key and nonce:
...
7
votes
1answer
349 views
Introduction to LLL algorithm applied to linear modular inequalities
What is the Lenstra–Lenstra–Lovász lattice basis reduction algorithm about?
How is it applied to solve for $x\pmod m$ a system of modular inequalities $(u_i\,x+v_i\bmod m)<w$ for $0\le i<n$?
I'm ...
2
votes
0answers
34 views
How are ChaCha-based ARC4Random CSPRNGs initialized and reseeded?
I'm doing a spare-time project to collect cryptographic algorithms, implement them, and lastly benchmark them.
For the CSPRNG part, I'm evaluating NIST-SP-800-90Ar1 HMAC-DRBG and CTR-DRBG (Hash-DRBG ...
0
votes
1answer
37 views
Understanding the Inner State of a RNG
Based on the BSI evaluation criteria for quality of deterministic random number generators:
K4 – It should be impossible, for all practical purposes, for an attacker to calculate, or guess from an ...
2
votes
1answer
145 views
Reverse Java seed using outputs generated from nextInt(6)+1
Given a set of numbers within the range of 1-6:
[3,4,3,4,5,6,2,3,1,5,2,3,6,2,2,3,3,6,6,4,5,2,5,3,5,2,4,4,2,6,3,6,1,5,1,3,6,1,1,2,2,4,5,3,1,2,3,4,4,6]
generated using Java's nextInt(6)+1, is it ...
2
votes
0answers
38 views
Fisher Yates on “faulted” random number generator cryptanalysis
For the sake of curiosity and fun, i have implemented a C# program that operate as deck dealer on 40 cards deck (following the Fisher Yates shuffeling algorithm https://en.wikipedia.org/wiki/Fisher%E2%...
1
vote
2answers
209 views
Why is breaking the Blum Blum Shub PRNG not an undecidable problem?
The Blum Blum Schub (BBS) pseudo random number generator (PRNG) is defined inductively by
$$
x_{i+1} = x_i^2 \mod N
$$
to generate the bit sequence $b_0b_1b_2...$ where the bits are taken to be the ...
0
votes
1answer
59 views
Is it secure to repeatedly rehash a digest to extend the digest length?
Upon reading through the source code of Rainbow, a post-quantum signature algorithm, I found a hashing function that, using SHA-512, produced a variable length digest.
This was achieved was by ...
14
votes
1answer
1k views
What issues are there while using Linux's /dev/urandom for generating cryptographic keys?
As of Linux 5.1 the /dev/random no longer uses the blocking pool. There is a talk about the change on the page Removing the Linux /dev/random blocking pool
I ...
1
vote
1answer
50 views
Lehmer random number generator cipher - looking for differentials
I'm looking for differentials in my kind of toy encryption scheme. I can't find any.
Let's consider linear congruential generator:
$X_{k+1} = a \cdot X_{k} \mod 2^{128}$
Such that $a$ is some number ...
5
votes
1answer
77 views
The Rationale behind NIST's counter/LFSR recommendation on deterministic IV constructions on SP 800-38D
The NIST has a "SP 800-38D: Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC". This guideline is a base for AES-GCM from definition to security ...
3
votes
2answers
175 views
What is the advantage of adversary if the random number repeats?
In proof of CPA-security of encryption scheme $(r, F_k(r)\oplus m )$
where:
$F_k$ is a keyed function
$r\in_R\{0,1\}^n$ is a random number,
on page 85 of Introduction to modern cryptography we have
...
1
vote
1answer
61 views
Getting a random number on an STM32L0x1 device for SRP6a
I'm trying to get a random number for a STM32L0x1 MCU to use it in protocol SRP6a.
(I know that there are MCUs with an embedded hardware random number generator. But it would cost twice as much as the ...
0
votes
1answer
44 views
Why does l'Ecuyer reject p-values close to 1?
When applying several tests to a given generator, p-values smaller
than 0.01 or larger than 0.99 are often obtained by chance even if the
RNG behaves correctly with respect to these tests (such values ...
0
votes
1answer
60 views
On the Acceptability of a Naive Pseudo Random Number Generator
My question is probably both philosophical and technical.
Background
I was developing a CSPRNG, and I needed to shuffle the bits in one step in the middle of the algorithm - any naive shuffle would ...
5
votes
3answers
3k views
Why is the output of a True Random Number Generator (TRNG) insecure after it has been compressed?
I came across the following statement regarding true random number generators (TRNG):
A “P1 medium” [AIS31] true random number generator (TRNG) may not be directly used due to cryptographic reasons. ...
0
votes
0answers
16 views
(RNG) For the Middle Square Method, is there a table of periods for various seeds?
I'm interested in the properties of the original middle square method as articulated by John von Neumann and in particular in the relation between seed value and its period length (in cases where the ...
1
vote
2answers
85 views
On The Next Bit Test
I would like to know what $O(v(n))$ really means in detailed and simple words please.
I found it everywhere in the literature I am reviewing but I cannot find what the intuition of it (especially if ...
2
votes
1answer
83 views
Using AES-CTR as a PRNG
AES-CTR is not considered as a CSPRNG, why ?
Is it unsecure to use it when a password is hashed with Argon2id to produce the seed to generate all random data needed for an end-to-end encyption system ...
2
votes
0answers
33 views
RNG and Mersenne twister learning resources for the amateur
I am a complete amateur in the area of random number generators. I would appreciate resources to begin learning.
Also I would also like to learn about Mersenne twister. Resources that are easy on the ...
7
votes
1answer
83 views
What quality of randomness is needed for randomized side channel countermeasures?
Using per-operation randomness is a popular and effective way to protect cryptographic implementations against side-channel attacks, e.g. using Shuffling (randomizing the processing order eg for AES ...
1
vote
3answers
215 views
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?
1
vote
1answer
197 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:
...
4
votes
2answers
139 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 ...
0
votes
0answers
82 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
votes
1answer
195 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 ...
1
vote
0answers
65 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 ...
0
votes
0answers
44 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 ...
13
votes
7answers
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 ...
1
vote
1answer
687 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 ...
0
votes
1answer
101 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 ...
0
votes
1answer
90 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 ...
0
votes
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 ...
0
votes
0answers
38 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}\ ...
1
vote
3answers
95 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 ...
5
votes
1answer
519 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 ...
3
votes
1answer
101 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 ...
3
votes
1answer
89 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 ...
2
votes
0answers
42 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´...
0
votes
1answer
91 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?
1
vote
1answer
115 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 ...
2
votes
3answers
159 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 ...
