creation of (real or pseudo) random numbers (or bits).
3
votes
1answer
109 views
How random are comercial TRNGS
I'm thinking about buying an USB TRNG. The question is: How do I evaluate it's randomness ? I'm sure some are better than others but which is which ? Are thermal-noise better than radio-noise TRNGs?
1
vote
2answers
101 views
True random numbers generated by sensors
Is using sensor raw data a good way of generating true random numbers? I mean using an IPhone's gyro/accelerometer raw output as a base for generating an array of true random numbers.
1
vote
2answers
81 views
CSPRNG in JavaScript using Audio and Video
I ported GnuPG to Javascript using Emscripten (not released yet).
Now I need a good replacement for /dev/random//dev/urandom.
...
0
votes
2answers
74 views
random number generator 10-side dice alternative
A lot of sites like this one Here, refer to 10-side dice to generate random number for otp. I was thinking about new ways to generate random numbers,letters and passwords. here what I got.
to ...
0
votes
1answer
99 views
Is this scheme a provably fair random number generation?
I have thought up a method for generating random numbers between a client and a server which I hope is fair:
The client and server decide on a range in advance, $0$ trough $n-1$.
The server ...
4
votes
1answer
164 views
Quality of randomness on a Linux system with haveged
Has anyone checked if using haveged, a Linux daemon which uses the HAVEGE algorithm, changes the non-deterministic properties of the random data from ...
5
votes
1answer
124 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 ...
2
votes
1answer
71 views
Potential vulnerability in DH key selection - am I understanding this right?
I'm reading through a DH implementation, and I think I found a potential hole.
Public $p$ and $g$ values are properly selected.
A candidate secret value $\bar a$ is pseudo-randomly selected such ...
2
votes
1answer
87 views
Is it feasible to break Diffie-Hellman key exchange when the implementation uses a poor-quality PRNG?
I've come across an implementation of DH in Java that uses the Random class to generate the secret integer value $a$, as shown in in Wikipedia's description of the ...
3
votes
2answers
84 views
Can I combine two PRNGs to make use of more seed data?
I have 320 bits of seed data (actually 512 bits of data with 320 bits of entropy, derived from a Diffie-Hellman shared secret and nonces). The PRNG I am using at the moment is the android version of ...
0
votes
2answers
139 views
Generate random number which should depend on key
i want to generate random number for example from [1..100].
This algorithm which generates random number should work similarly like ("Linear congruential generator").
Here:
c - increment should ...
1
vote
2answers
67 views
GGM PRG construction: Why do we need to change keys all the time with underlying PRG
When constructing a PRF that has n bit input using the GGM PRG, why do we always have to recursively run the PRG using its previous output as a seed key n times. Instead, why don't we run the PRG n ...
-2
votes
1answer
60 views
Cryptographic Primitive Method
Is there any cryptographic primitive bijective (one-to-one and onto) function for creating cryptographic tools like symmetric encryption/decryption, Hash code generator, MAC, HMAC and Random number ...
4
votes
3answers
208 views
Initialize a PRNG with a password
Let's assume that we have a secure PRNG. Is it "safe" to initialize it with password, or seed based on a password like SHA256(password).
If yes, is it "safe" to generate as RSA or DSA key from it? If ...
2
votes
0answers
108 views
Odds of false error detection in a randomness test using the chi-squared test?
Common Criteria classifies the requirements for true Random Number Generators, and specifies how these should be tested against failures (these can occur accidentally, or following deliberate attack, ...
1
vote
1answer
105 views
Why does Fortuna (RNG) require entropy sources to specify accumulator pool?
Re-reading my copy of Cryptography Engineering for the holidays, I was struck by the following question about the Fortuna RNG:
Why require an entropy source specify which pool a random event should ...
3
votes
2answers
116 views
Good enough deterministic PRNG based on hashes
Lets say I have a seed named iv which has a decent amount of entropy.
Are there any glaring issues with the following?
First 64 bytes are generated by SHA512(iv)
Next 64 bytes are generated by ...
2
votes
2answers
139 views
How to generate a random integer in interval $[1, 2^n-1]$ from random integer in interval $[0, 2^n-1]$?
For a project I am working on, I have access to a CSPRNG that outputs a random integer in the interval $[0, 2^n-1]$ for any integer $n$ greater than 0. I cannot use the zero values, so I have my RNG ...
5
votes
2answers
307 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)
...
2
votes
3answers
252 views
ANSI X9.31 standards for generating random numbers
The NIST-Recommended Random Number Generator Based on ANSI X9.31 Appendix A.2.4
Using the 3-Key Triple DES and AES Algorithms has 3DES being used three times for each 64-bit block of random data ...
2
votes
1answer
205 views
Webcam random number generator
I have a question about random number generators.
I have read from a real random number generator, based on a webcam ("randcam"). My problem is, that I do not really understand how the generation of ...
-1
votes
1answer
92 views
Pseudo-random Number generation for Passwords
i want to know what is the best pseudo-random number generation algorithm for passwords? for example my scenario is I have to generate 5K pseudo-random bits from a user-supplied password(6 ...
6
votes
3answers
159 views
Does chaining random number generators lead to loss of randomness?
Assume you chain random number generators, i.e use the result of one PRNG as the seed for the next. What kind of errors can that introduce in the randomness of the numbers generated?
2
votes
1answer
109 views
Seed a PRNG with random data and a password
I'd like to combine a random key file with a password to generate a secure seed for a CSPRNG. The key file is assumed to have very high entropy, but the password will be whatever the user provides. ...
3
votes
1answer
180 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 ...
1
vote
2answers
214 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
1answer
203 views
server side Javascript security
It is accepted that the javascript library lacks the ability to create an adequate PRNG. My understanding that this was mainly due to the limits of a sandboxed browser enviroment that javascript ...
2
votes
1answer
140 views
Proving correctness of pseudorandom generator construction given existing pseudorandom generator
Say if I have a given pseudorandom generator G which takes a k-bit input and outputs a 3k-bit number.
How should I show that a specific construction using this pseudorandom generator is valid?
For ...
0
votes
0answers
99 views
Secure Pseudorandom Number Generators [closed]
Can anyone list the pseudo-random number generators used in todays stream ciphers that are considered secure or highly resistant to cryptanalysis?
2
votes
4answers
341 views
Which is more secure using a CSPRNG for a One-time pad, or AES?
In reading about the One-time pad it appears to need truly random key for the pad. Since true random values are not practical to generate this presents a problem (thus making One-time pad less ...
5
votes
2answers
485 views
HRNG for One Time Pad
I have just advanced to the last grade of high school (in Denmark). In this year, we all get to do one big project, where we can build/invent/create whatever we want to "solve a problem". As I study ...
2
votes
2answers
183 views
Is any decent RNG acceptable as a stream cipher?
I have a function f(x,n) that takes a 128-bit key x, and generates n bytes of pseudo-random data. I've tested the output bytes this function for various keys with the NIST RNG testing suite (NIST ...
9
votes
2answers
545 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 ...
-1
votes
2answers
310 views
Are mouse movement coordinates useful as a seed for a RNG?
Is it good to use a mouse movement as a 64-bit random seed for a Pseudorandom Generator like AES in Counter Mode?
Should I only need to get the X and Y coordinates of the mouse movement?
1
vote
1answer
142 views
Generating a cryptographically secure, many-time use, symmetric encryption key
I need to generate a 256 bit encryption key described by the adjectives in the title. Currently I intend to create the key using this RNG.
Is this a secure manner of creating the key, given that it ...
2
votes
3answers
225 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 ...
2
votes
1answer
166 views
Conforming Randomness To An Alphabet
Imagine that we're trying to create a function to generate a random string conforming to a user-supplied alphabet. That way, users can generate random strings with given characters. Something like:
...
1
vote
3answers
217 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 ...
4
votes
1answer
210 views
I need an opinion of encryption method I thought of in High school
First, I'm really not into cryptography, but have some basic knowledge. This was a thought experiment (and later exercise for my programming skills), but even though it was long time ago and I tried ...
4
votes
2answers
288 views
How many bits can be safely extracted from the BBS generator at each step?
The Blum-Blum-Shub generator is a deterministic Pseudo-Random Bit Generator with security reducible to that of integer factorization.
Setup: Secretly chose random primes $P$, $Q$, with $P\equiv ...
-4
votes
1answer
337 views
128-bit Pseudorandom number Generator
Is there any 128-bit pseudorandom number generator available?
I tried the Blum Blum Shub Generator, but I can't produce a 128-bit pseudo-random number.
Maybe before I produce a 128-bit pseudorandom ...
2
votes
2answers
127 views
Does a hash function in chaining mode or in counter mode make a better pseudo-random number generator?
I have two pseudorandom generators:
$f_1$ takes a random seed $l_0||r_0$ $\in \{0,1\}^{160}$ as input and outputs $r_1||r_2|| \dots ||r_k$, where $l_i||r_i = \operatorname{SHA-1}(l_{i-1}||r_{i-1})$ ...
4
votes
1answer
267 views
How secure is my OTP program?
I'm writing an One-Time Pad encryption program, because I got really interested in the idea of " encryption which has been proven to be impossible to crack if used correctly".
I'm writing the program ...
2
votes
1answer
287 views
Linear Feedback Shift Register Taps
Linear feedback shift register tap charts are availale for registers of length 3 to 168. Does anyone have a chart for register lengths from 168 to 256 or beyond? Thank you.
1
vote
1answer
97 views
Can A PRNG Be Used To Generate Multiple Private Keys for ECDSA?
Suppose Alice seeds a cryptographically strong Pseudo Random Number Generator with a truly random number, and keeps it secret. Alice then uses the output of the PRNG to generate several 256-bit ...
1
vote
2answers
165 views
How do I demonstrate that a PRNG not designed for cryptography is not suitable for generating passwords?
This is a replication of this question on Stack Overflow. There's class Random in .NET runtime which is designed for use as a cheap fast source of pseudo-random ...
6
votes
1answer
564 views
Generating Random Primes
Although this has been extensively discussed around here, I'm curious whether my approach makes sense, or I should just stick to "the standard version".
I'm implementing some homomorphic encryption ...
2
votes
1answer
340 views
What is the correct way to generate cryptographically-secure pseudorandom numbers in C?
I am learning about crypto, purely for my own interest. As part of that I am implementing a simple 'one time pad' toolset in C.
Naturally I need to generate random numbers to create the pad, and they ...
4
votes
2answers
244 views
Predicting PRNG given some of its previous output
I a have a question about PRNGs and this is my very first experience with them. I have the following generator that takes a 56-bit seed 'p' during initialization and then chooses both X and Y randomly ...
0
votes
1answer
155 views
Cryptographically strong pseudo-random seq. generators
If a pseudo-random sequence generator is built so that it uses an n-bit seed and outputs a string that is of length x. Let's say one wants to generate a bit string of length y and uses the previous ...
