<p>Do not use such a file from any (public) source!</p>
<p>Generate it yourself always, preferable off-line.</p>
<p>On linux:</p>
<pre><code>dd if=/dev/urandom bs=1024 count=1 2&gt; /dev/null 1&gt; seed.bin
</code></pre>
<p>This file can be read by vanitygen if you execute it with the -s option, like so:</p>
<pre><code>$ ./vanitygen64 -v -s ./seed.bin 1XYZ1
Read 1024 bytes from RNG seed file
Prefix difficulty:            264104224 1XYZ1

...
</code></pre>

CC BY-SA 4.0
2021-07-15T08:55:09.767Z
2021-07-15T09:05:42.817Z
2021-07-15T09:05:42.817Z
Ytsen de Boer
<p>It uses RAND_load_file function from OpenSSL, which accepts any binary input - random bytes. Under Linux and OSX the /dev/random file can be used, I don't know  equivalent under Windows. However, OpenSSL uses /dev/random by default, so there is no improvement using it explicitly. </p>

<p>Only scenario might be when you need faster random numbers generator, as /dev/random is quite slow and you start vanitygen very often. Then you can for example use /dev/urandom (but in this case you expose yourself to small but perhaps exploitable possibility that the seeds for generated addresses will be related). Certified hardware random numbers generators would be preferred in this case (some recent Intel and VIA CPUs have one).</p>

CC BY-SA 3.0
2012-12-12T02:01:13.167Z
2012-12-12T02:01:13.167Z
Juraj
<p>or you can get some random bytes file ftom <a href="http://www.random.org/" rel="nofollow">http://www.random.org/</a> and use it as your imput</p>

CC BY-SA 3.0
2015-11-27T06:00:38.963Z
Actually it is not recommended since data from random.org is public and it could be used to attack you.
Felipe
CC BY-SA 3.0
2013-05-18T22:01:34.070Z
2013-05-18T22:01:34.070Z
413j0
<p>Vanitygen has the option for a file to contain random numbers as an alternative to the built-in random number generator.</p>

<p>What is the correct way to generate this file on Windows, OSX? (and Linux)</p>

<p>What is the range of each number (upper and lower bound)?</p>

<p>What is the correct format of the file (CRLF, LF only)?</p>

<vanitygen><random>
Need a random seed for vanitygen; where can I obtain one?
makerofthings7
# Need a random seed for vanitygen; where can I obtain one?

(Asked by: username_0 on 2012-12-11)

Vanitygen has the option for a file to contain random numbers as an alternative to the built-in random number generator.

What is the correct way to generate this file on Windows, OSX? (and Linux)

What is the range of each number (upper and lower bound)?

What is the correct format of the file (CRLF, LF only)?

**Tags:** vanitygen, random


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## 3 answers

### Answer by username_1 on 2021-07-15. Score: 1

Do not use such a file from any (public) source!

Generate it yourself always, preferable off-line.

On linux:

```
dd if=/dev/urandom bs=1024 count=1 2> /dev/null 1> seed.bin

```

This file can be read by vanitygen if you execute it with the -s option, like so:

```
$ ./vanitygen64 -v -s ./seed.bin 1XYZ1
Read 1024 bytes from RNG seed file
Prefix difficulty:            264104224 1XYZ1

...

```


---

### Answer by username_2 on 2012-12-12. Score: 1

It uses RAND\_load\_file function from OpenSSL, which accepts any binary input - random bytes. Under Linux and OSX the /dev/random file can be used, I don't know equivalent under Windows. However, OpenSSL uses /dev/random by default, so there is no improvement using it explicitly.

Only scenario might be when you need faster random numbers generator, as /dev/random is quite slow and you start vanitygen very often. Then you can for example use /dev/urandom (but in this case you expose yourself to small but perhaps exploitable possibility that the seeds for generated addresses will be related). Certified hardware random numbers generators would be preferred in this case (some recent Intel and VIA CPUs have one).


---

### Answer by username_3 on 2013-05-18. Score: -1

or you can get some random bytes file ftom <http://www.random.org/> and use it as your imput

> **Comments:**
> **username_4**: Actually it is not recommended since data from random.org is public and it could be used to attack you.  

---

