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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Is it possible that PracRand did not detect looping of the generator?
I'm testing my own PRNG generator which should has period $2^{38}$ bytes. So after exactly $2^{38}$ bytes it should start repeat. But PractRand find no anomalies after $2^{39}$ bytes.
Could it be that ...
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RNG Distribution with multiple instances [closed]
If I need to generate random 8 bytes with RandomNumberGenerator class, I can generate all 8 bytes with a single instance and also I can use two instances of ...
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1answer
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Exponentiation of Linear Congruential Generators
Linear Congruential Generators, that class of pseudo random generators with recursive rule
$x_{n+1}\equiv a\cdot x_n +b\ \ (\mod m)$, $a,b,x_n\in Z/mZ$, $m,n\in N$
are considered inapt for use in ...
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1answer
68 views
Where is the specification for SHA1PRNG?
I searched for the algorithm of the SHA1PRNG, which is implemented in Java's SecureRandom Class. Does anyone know how this algorithm works exactly? I have not found a source where the algorithm is ...
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1answer
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Average spectral score of multiplier in LCG
LCGs have a property that when plotted in 2 or more dimensions, lines or hyperplanes will form, on which all possible outputs can be found.[2] The spectral test compares the distance between these ...
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1answer
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Do there exists PRNGs that provably pass the next bit test?
I am wondering if there are any results in literature which construct a PRNG that is proved to pass the next bit test? If so, can you state what the PRNG is and where I can find more details on it? ...
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2answers
134 views
Household sources of secure randomness?
In my home, I have a coin. I can use that coin to generate random bits. These bits are mostly secure unless someone is watching me flip it. They're also only random-ish... maybe I'm a "bad ...
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Questions about Blake2x: Its state size (internal state) and its security when generating keys with size more than 256/512bits
I read the Blake2x paper: https://www.blake2.net/blake2x.pdf
It says Blake2x can be used to build a "DRBG" (CSPRNG): https://csrc.nist.gov/glossary/term/deterministic_random_bit_generator
&...
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How to connect an external noise source file to openssl-fips-2.0.16
[ECDSA][ECDH]
Due to Insufficient Entropy in Operating system of MCU
=> Could not generate random number by using BN_rand() function
(security strength fail, and RAND_bytes fail)
Below is my ...
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1answer
81 views
Existence of algorithm predicting next bit in output sequence
Let $X = [0, 1]\cap \mathbb{Q}$, and let $f:X \rightarrow X$ be a chaotic map (i.e. the logistic map with rational parameter). My question is as follows, and is purely theoretical in nature. Pick ...
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Is it possible to crack a Linear Congruential Generator if I only know the modulus of the output?
Edit suggested by fgrieu:
I have one hundred integers in $\{0,1,2,3,4,5\}$ which I suspect are consecutive values of $\lfloor x_n/2^{16}\rfloor\bmod6$ computed as $x_{n+1}:=a\cdot x_n+b\bmod m$, with $...
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Are PRNGs Key Derivation Functions?
PRNG is a mechanism to produce randomness from an initial random seed, so basically a way to derive more secrets from one secret.
Looking at the Wikipedia entry for KDF you find
In cryptography, a ...
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How to check security strength of random k if k is an input parameter of ECDSA signature generation function using openssl-fips
As I understand,
1.The security strength is specified in bits according to https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf
2.Security strength is depend on the length of ...
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108 views
When are PRNG used and when are CSPRNG used
I understand that PRNG are Random Number Generators that uses a deterministic algorithm based off of a seed.
I also understand that CSRNG are PRNG that are cryptographic-ally safe to use for ...
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2answers
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Is it insecure to make nonce using random number generator and hashing algorythm with secret key like HMAC?
I'm building a project on Arduino Mega microcontroller and I need some nonce generator for challenge-response exchange. But I failed to find some alphanumerical string generators. Then I came up with ...
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Node.js uuid.v4 vs crypto.randomUUID. Which implementation is more cryptographically secure?
For a long time I've used the uuid npm package for my v4 uuid needs. It seems in recent versions of node they have introduced a built-in crypto module with the method randomUUID.
Some benchmarks have ...
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1answer
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Is hashing random numbers generated from a TRNG enough to create a key? [duplicate]
Is hashing random numbers generated from a TRNG enough to create a key?
Basically taking the output of something like a Lavarand and pass that through a hash function like sha-2.
I guess at the end of ...
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How are the keys used in cryptography generated?
It seems there are keys everywhere in cryptography. From things like HMAC to encryption (both asymmetric and symmetric).
The bit I do not totally understand now is how are cryptographic keys generated?...
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1answer
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DIY TRNG on an embedded system for Ethereum private key generation
I'm trying to build this Ethereum hardware wallet on a custom designed embedded system and I'm no expert. Googling around I found this Robust, low-cost, auditable random number generation
for embedded ...
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2answers
423 views
Difference between Non-uniformly random and Uniformly random
I am reading up on Key Deriving Functions (KDF) and in a section of the Real-World Cryptographic book by David Wong, a comparison is being made with Pseudorandom number generator (PRNG). And one of ...
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Mersenne twister word size and degree of recurrence combination
For a 32-Bit variant of Mersenne twister, if the outputs Should be a 5-Bit integer(word size) then what is the value of recurrence according to the k-distribution?
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Program to predict a 5-bit output from mersenne Twister random module from python
Is there a program to predict the mersenne twister random module in python for a 5-bit integer output, provided the consecutive 3994 outputs are available?
The random module is not seeded so i guess, ...
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How to reproduce seeds in Random Number Generator like WELL, KISS etc
I am curious about Padding the seeds of Random Number Generator.
(I am sure that terminology, padding the seeds, is not correct. If someone knows the proper word, please let me know :) )
What is ...
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Can AES fail PractRand?
Mellisa O'Neil tested Xoroshiro128+ with 512 terabytes (2^49 bytes) of data. And finally it failed. Would AES fail PractRand with enough data?
When we can expect that AES will fail? Maybe with $2^{64}$...
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463 views
A source of randomness that anyone can independently, conveniently and robustly access?
Does there exist a source of randomness that anyone in the world can independently, conveniently and robustly access?
For example, the 10th decimal place of the temperature in Mexico City is ...
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2answers
187 views
What are the fastest algorithms that sample from the uniform distribution?
Lots of cryptography algorithms rely on pseudorandom number generators. Sometimes, given a plaintext, you need to generate a pseudorandom number from it. What are some fast algorithms that do so?
I've ...
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1answer
68 views
When not to reject a random number generator?
I have constructed a true random number generator, and I applied the NIST randomness Test Suite to its results. I have generated around 200 files with my TRNG, each being $10^6$ bits in length.
The ...
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1answer
48 views
Randomness extraction on correlated data in TRNG
True random number generator (TRNG) designs I read about mostly consist of two digital stages:
Low-frequency sampling (of a physical noise source)
Randomness extractor
The noise signal is sampled at ...
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1answer
209 views
Randomness extraction from a Santha-Vazirani (semi-random) source
In a quest to better understand randomness extractors (in the context of TRNG post-processing), I read some papers about the von Neumann Extractor and Santha-Vazirani (SV-) sources. The von Neumann ...
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How can I recover mersenne twister when only the part of the bits?
https://github.com/tna0y/Python-random-module-cracker
Here, when we get 32*624 bits of outputs from Mersenne-twister we can recover Mersenne twister. My question is when we get the parts of the bits, ...
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Can we combine two true random generators to obtain a new one?
It is well known that a true random generator exploits the randomness occurs in some physical phenomena. Also, the output of a true random generators can be either biased or correlated. Therefore, de-...
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Design an algorithm to generate random session key
good day.
I am asked to design the a simple algorithm to generate random session key id of block length of 8 and change continuously every time it refreshes. Is there any simple algorithm to create ...
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Security proof for PRNG
Could you help to find an example of where the next kind of proof is performed, please?
"if we can distinguish the randomly generated bits of a PRNG from a random sequence, then we can ...
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2answers
134 views
CSPRNG in Javascript?
I'm trying to obtain a random, unpredictable quite long number (± 20-25 digits) using Javascript (created by user's client) as fast and light as possible. Is this solution reliable, robust and secure ...
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Is using /dev/hwrng for raw key material secure?
Is using /dev/hwrng for raw key material secure (as long as you trust the hardware)?
I tested it using the rngtest tool and it has good output.
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How to compute the dataset size required by dieharder tests?
I am trying to use the dieharder random number test suite.
However, this suite requires massive amount of data (this paper claims 228GB for no rewinding for every test) for most of the tests. I'd like ...
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Mismatch between NIST SP800-90A test vectors and CTR_DRBG output
I am testing my Python implementation of NIST SP800-90A CTR_DRBG https://csrc.nist.gov/publications/detail/sp/800-90a/rev-1/final (AES-256, no df) with the CAVP test vectors (https://csrc.nist.gov/...
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Rigorous practical pseudorandom generators
It is known that existence of pseudorandom generators (PRGs) is equivalent to the existence of one-way functions. In turn, the latter is an open problem.
I am curious if someone developed kind of &...
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2answers
124 views
Does watching Youtube generate entrophy
Does watching videos (either online videos such as off youtube or saved locally) generate enough (if any) entropy to create secure encryption keys? I understand that some activities such as memory ...
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Benchmark for CSPRNG as stream ciphers?
My limitation in my security protocol is that I want my RNG as CSPRNG and I also want it to be super fast.
If I use Salsa20 or ChaCha or AES counter mode, I don't get the desired speed. I want my PRNG ...
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2answers
409 views
Is a LFSR sufficient for post-processing a biased TRNG?
I am building a TRNG on a FPGA based on ring oscillators. I found out that Linear Feedback Shift Registers (LFSRs) are commonly used for the post-processing of TRNGs. Here is my initial design:
Let's ...
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1answer
164 views
Which test suit is better to say if PRNG is CSPRNG:TestU01 or NIST?
Actually my concern is that I am planning to apply xoshiro256+ for implementation of stream cipher https://prng.di.unimi.it/
for my cryptographic application. It passes the BigCrush tests. Will it ...
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Distributed Random Oracle with Verifiable Shares
$Setup$:
Let's assume a quorum of $n$ nodes where each have a secret share $y_i$ from a know and safe leaderless DKG protocol.
Define $\mathcal{L}^i(y_i) = y$ as the lagrange interpolation for $x=0$, ...
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Is multiple encryption with stream ciphers vulnerable to meet-in-the-middle attacks?
Let's suppose I encrypt something with a stream cipher (CSPRNG) two times using two 256-bit keys and different IVs.
Will I get 512-bit encryption strength?
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What is novel about Seedless RNGs?
Seedless Fruit is the Sweetest: Random Number Generation, Revisited introduces a theoretical framework for "seedless" RNGs.
AFAICT, this framework injects entropy directly into the ...
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Why are $\lceil 1/\operatorname{entropy-per-bit} \rceil$ number of bits not sufficient to generate an unbiased bit?
Consider a biased RNG badrand() generating 1 with probability $0.9$ and 0 with probability $...
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1answer
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What is the NIST recommended maximum bias for random number generators?
What is the maximum bias recommended by NIST for random number generators?
This answer says that it is $2^{-64}$.
Is it same for all applications? Does NIST have a publication with more information?
I ...
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3answers
279 views
How to combine $n$ 'less random' bits to generate one 'more random' bit?
Suppose we have a random number generator badrand() generating 1 with probability $0.9$ and 0...
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Random number generator in C++ [closed]
I've wrote a simple random number generater in C++.
Simply, I thought, the random things in software. I wrote it based on below:
When an object is created on the stack, its address is random.
The ...
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1answer
244 views
On the initializaton of the "xorwow" PRNG
In the original paper, Marsaglia defines the xorwow() function and gives some example values for the initial state of $x$, $y$, $z$, $v$, $w$ and $d$. But it is not ...
