Questions tagged [random-number-generator]

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convert decimal random values to binary for ent testing

I have ascii random values from /dev/urandom in a file like: 435 678 437 897 They are uniformly distributed and have perfect average. feeding the file to ent test suite yields low entropy value and ...
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1answer
51 views

Generating (pseudo) random numbers from a log file (eg. /var/log/maillog)

First: I really know that a true random number generator should have real random input, like something that is impossible to predict. Now, consider this: A busy mail-server can generate tens of ...
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2answers
10k views

Can't load /root/.rnd into RNG : where can I find it, or how to create it?

I'm trying to setup a VPN server with OpenVPN, on an Ubuntu Server 18.04, and I want to use EasyRSA to build my PKI CA. So, while connected as root, I launch the EasyRSA scripts which I copied to /...
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118 views

Kernel random numbers generator fails on VMWare in a Debian VM - “Cannot find a hardware RNG device to use”

On a VMWare hypervisor in Apache CloudStack context, I get the following error with Debian 10: Aug 19 18:52:10 vm-ednus-1046 rng-tools[632]: Starting Hardware RNG entropy gatherer daemon: (Hardware ...
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1answer
41 views

Entering a random number sequence seed under surveillance [closed]

I'm trying to transmit a continuous sequence of random numbers from my computer over to another country (for validation purpose). This sequence is a series of pseudo random numbers recursively ...
52
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2answers
6k views

dd is producing a 32 MB random file instead of 1 GB

I wanted to produce a 1 GB random file, so I used following command. dd if=/dev/urandom of=output bs=1G count=1 But instead every time I launch this command I get a 32 MB file: <11:58:40>$ dd ...
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0answers
343 views

Configure the default Random Number Generator algorithm in Windows.

How do I configure the default random number generator on Windows? Windows 7 and above. I would like to check whether the "Dual Elliptic Curve Deterministic Random Bit Generator (Dual EC DRBG)" ...
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1answer
391 views

RANDBETWEEN but smaller than another cell value

I would like to generate a number that is random but smaller than the cell above (I'm doing 4th grade subtraction worksheet). What is the formula for this? I tried =randbetween(C3, 99) but it didn'...
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1answer
51 views

Excel formula Help: Random sequence number

Would like to seek assistance for excel formula for difference between two or more numbers . In this sample if i put value randomly in cell G2 is there formula to put generate random number between ...
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1answer
35 views

TrueRNG Pseudo GUI Issues - Collision

I am trying to create a Pseudo GUI for the TrueRNG Hardware using RNGCapture.exe and a custom Batch Based Menu. The RNGCapture program is only command line and a Royal Pain to create Multiple Entropy ...
4
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1answer
258 views

Play random movie/episode within a folder from its context menu

The Goal I have a relatively expansive media collection stored locally on my machine within two parent folders ("Movies" and "Shows"). My goal is to be able to play at random any one of the movies or ...
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1answer
4k views

Auto generate unique number with no duplicate

How can I auto generate number if 1 of the column is fixed with the number that I want and another column randomly generate the number that is not in first column? I do not want any duplicate. For ...
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0answers
290 views

Unable to plot a scatter plot in excel

I have taken integers from 1 to 100 as my total population set. Now I generated 5 random numbers (using =randbetween() command) and called it my sample 1. Similarly, I created 200 such samples. Now I ...
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1answer
935 views

Biased Random results in Excel

Over on WorldBuilding we like to play with science-fictiony themes, including "what if there were more that two sexes" (examples here, here, here). All good clean fun and, I thought, a chance for me ...
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3answers
2k views

How often does /dev/urandom sample seeding from /dev/random?

Unless I am totally confused and it doesn't do that. I want to know whether or not /dev/urandom will gain increased entropy if I take a hardware RNG and plug its entropy into /dev/random. So to ...
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1answer
328 views

cat /dev/random brings up print dialog

I was just messing around and in the terminal of my Mac I did cat /dev/random just to watch the endless stream of random values. It has now brought up a print dialog and it wants to print half a page ...
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1answer
1k views

What AMD processors provide RDRAND?

The latest AMD programmer manuals, dated June 2015, include the RDRAND instruction in the instruction set. Confer, AMD64 Architecture Programmer’s Manual Volume 3: General-Purpose and System ...
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1answer
1k views

Should I use “/dev/random” or “/dev/urandom” for large random data needs? [duplicate]

Sometimes I want a lot of highly-random data, for example to overwrite a file or even a whole hard disk. Should I use /dev/random or /dev/urandom? What are the advantages or disadvantages of each? Is ...
3
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1answer
4k views

Why am I constantly running out of entropy?

So I've been trying to create a new GPG key, and keep getting this well-known error: Not enough random bytes available. Please do some other work to give the OS a chance to collect more entropy! (...
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2answers
958 views

\/?' was unexpected at this time error in batch file

I am trying to integrate a password generator into my batch file so that it generates multiple passwords. Unfortunately it give the following error: \/?' was unexpected at this time. The expected ...
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2answers
497 views

Random selection with a caveat / criteria

I have a 6 x 6 grid. I have 36 samples split into three equal groups (A, B, and C). I want a formula to arrange the samples in that grid randomly. However each row and each column must contain two of ...
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3answers
1k views

How do computers generate random numbers

This may very well be the only question I ever ask on this stackexchange site. In programming there are many different ways to generate random numbers depending on different languages. What has been ...
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1answer
2k views

How do I generate random numbers between a range in cells? [duplicate]

I'm wanting to create a button that generates a string of 10 random numbers into cells, and pulls the range for these random numbers from, for instance, in B1 and B2. Basically, I'm looking to use the ...
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1answer
614 views

Not quite grasping /dev/random and /dev/urandom

I am not quite understanding the difference between /dev/random and /dev/urandom on Linux systems. What does it mean to run out of “entropy” and how does the system get more? What does it mean when ...
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1answer
1k views

How to generate inverted normal random numbers in VBA?

I am trying to generate 5.000 random variables using these excel functions: normsinv(rand()). This is the code I wrote: Dim r As Integer r = 1 For r = 1 To 5001 .Cells(r + 1, 1) = Application....
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1answer
546 views

How do computers generate random numbers? [closed]

How does a computer generate 'random' numbers? How close to truly 'random' can a number generated by a computer actually be? Is there software / programming language out that that might generate a ...
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4answers
17k views

Creating a large file of random bytes quickly

I want to create a large file ~10G filled with zeros and random values. I have tried using: dd if=/dev/urandom of=10Gfile bs=5G count=10 it creates a file of about 2Gb and exits with a exit status 0....
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3answers
79k views

How to keep random numbers from changing in Excel?

I am trying to generate a set list of random numbers between 1 and 5 using the RANDBETWEEN formula. I'm running into a problem that every time I click another cell anywhere in the sheet or even open ...
672
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18answers
79k views

How are pseudorandom and truly random numbers different and why does it matter?

I've never quite got this. Just say you write a small program in any language at all which rolls some dice (just using dice as an example). After 600,000 rolls, each number would have been rolled ...
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1answer
2k views

Is reading from /proc/sys/kernel/random/entropy_avail draining entropy?

When I'm doing watch cat /proc/sys/kernel/random/entropy_avail, the amount of entropy steadily decreases, until I get about 150-200. Initially I get over 2000. When I stop reading that value and wait ...
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1answer
2k views

Excel VBA: Rnd() method isn't random enough

I'm using Excel and VBA to simulate a large number of dice rolls. The problem I'm having is after a certain period of time, the rolls start repeating, and I start getting results that are anything ...
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1answer
2k views

Randomly reorder pages in PDF document

I'm looking for a series of commands to randomize the order of pages in an existing PDF document.
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3answers
19k views

Why does `cat /dev/urandom` break your terminal?

In reference to this question: https://serverfault.com/questions/534449 How does cat /dev/urandom make some terminal emulators go wonky?
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2answers
29k views

MS Excel: Unique random number generator within a range

I searched for a similar question but couldn't find one.. I want to generate 10 groups out of numbers ranging from 1-60 (including both), with each and every group containing random and non-repeating ...
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1answer
1k views

Calculating mean of value across random trials/refreshes in Excel?

Say I have a 1000 cells filled with random values and a particular cell that computes a final answer based on those 1000 values. Now I wish to track the value of the answer over 1000 trials i.e., I ...
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3answers
1k views

What's the best way to get a random(ish) sequence of printable/alphanumeric characters?

I know I can get random (well, pseudo-random) characters, unconstrained, from '/dev/random' (or /dev/urandom). But what if I need these characters to generate a filename? I need to somehow have a ...
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3answers
5k views

How can I know whether my machine have RNG hardware support?

I came across a blog concerning entropy pool problem and learn that there are a special hardware called RNG. I have read this kernel RNG page but I still wonder whether there is a way to find out if ...
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3answers
789 views

Random Number in Linux

In linux /dev/random is based of "environmental variables" and /dev/urandom is based off an algorithm and the time. My questions are: Where does /dev/random gather these variables from. And if you ...
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3answers
6k views

how to record mic input and pipe the output to another program

Hi everyone Im trying to follow a tutorial on generating truly random bits How To Generate Truly Random Bits This is the command from the tutorial but it does not work rec -c 1 -d /dev/dsp -r 8000 -...
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3answers
930 views

How to generate random numbers with a .wav file?

I want to generate random numbers within a certain range (1 to 26) using a .wav file with only static noise. The results need to be repeatable. Is there any service/program/method of accomplishing ...
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1answer
416 views

Are GPG keys generated on windows as secure as ones generated on linux?

Under linux you run out of system Entropy when trying to generate GPG keys unless you use /dev/urandom. Under windows, you get the speed of /dev/urandom without any tweaks. Does windows have that ...
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2answers
9k views

Why is GNU shred faster than dd when filling a drive with random data?

While securely erasing a hard drive before decommissioning I noticed, that dd if=/dev/urandom of=/dev/sda takes nearly a whole day, whereas shred -vf -n 1 /dev/sda only takes a couple of hours with ...
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2answers
2k views

How to determine a coin toss online? [closed]

What resources can I use if I'm trying to settle a coin flip online? Obviously, a coin toss app won't work if it only displays the result to me - the other party should also see it. And we can't meet ...
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2answers
897 views

Have a script execute a command randomly every now and then

I have a script which I am scheduling to run daily with Cron. However I want a certain section of the script to only run randomly occasionally, with a certain probability of executing on any given ...
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5answers
28k views

Why is my /dev/random so slow when using dd?

I am trying to semi-securely erase a bunch of hard drives. The following is working at 20-50Mb/s dd if=/dev/zero of=/dev/sda But dd if=/dev/random of=/dev/sda seems not to work. Also when I ...
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7answers
32k views

how do you make a letter password generator in batch?

I'm having a hard time figuring out how to make a password generator with random letters in it. For example, ASWED-ASDWAD-EFEST. So far I can only make random numbers by using the code @echo off :...
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1answer
1k views

Math Round multiple cells, generate integers and histogram integer values

I want your help for the following points: How generate integer values using Data menu > Data Analysis > Random Number Generation or (if this action can't be done) how round multiple cells in same ...
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3answers
718 views

Does 'urandom' share the same entropy of 'random'?

Does the entropy pool /dev/random used the same to /dev/urandom? I want to mknod /dev/random 1 9 to replace the slow random, I think the current entropy is randomly enough, if urandom is based on ...