<ol>
<li>Difficulty tells you how likely it is that vanitygen will be able to find the address pattern you're looking for on the next guess. A value of 2n is twice as difficult (half as likely) than a value of n.</li>
<li>Because the process is completely random, it's impossible to give you a '100%' ETA. We can only estimate that, on average, you will find your key before some time period <em>half</em> the time (hence why 50% is used). Note that it re-adjusts the value to 75% once it hits that 50% mark (and re-adjusts again after hitting 75%, until the key is eventually found).</li>
<li>That is the likelihood that you would have found your key by <em>now</em>, from the time when you started generating your key.</li>
</ol>

CC BY-SA 3.0
2016-07-28T07:01:53.593Z
Thank you. Do you know why finding alphabet is more difficult that finding only digits address: `1abcdef` takes more time than `1123456`
Aminadav Glickshtein
CC BY-SA 3.0
2016-07-28T04:24:29.553Z
2016-07-28T04:24:29.553Z
Klakurka
<p>I am running this command</p>

<pre><code>$ vanitygen64.exe 1abcdefg
Difficulty: 778316249440
[125.17 Kkey/s][total 39015067414][Prob 4.9%][50% in 46.3d]
</code></pre>

<ol>
<li><p>What is it mean <code>Difficulty</code>? I understand that higher takes more time, but what is the scale, why it is different from total? Why alphabet is more difficult than only digits <code>vanitygen</code>1234567`?</p></li>
<li><p>What is it mean <code>50%</code> in 46 days, why it not tell me 100%. After 46 days, how much percent will be that it will complete in the next 46 days? If it is same reasons  as in <a href="https://en.wikipedia.org/wiki/Half-life" rel="nofollow">Half-Life in nuclear physics</a> I understand it.</p></li>
<li><p>The big question. What it is <strong><code>Prob 4.9%</code></strong>? <code>Prob</code> of what?</p></li>
</ol>

CC BY-SA 3.0
2016-07-27T12:06:04.223Z
General warning: use of vanity addresses is bad. Bad for yourself and bad for others you transact with. Address re-use is bad for privacy and safety.
Jannes
CC BY-SA 3.0
2016-07-27T12:59:25.973Z
I know. But it is for a gift. Giving someone BTC on his name, then he can use it once...
Aminadav Glickshtein
<wallet><address><vanity-address><vanitygen>
What is it mean Difficuly & prob when using vanitygen?
Aminadav Glickshtein
# What is it mean Difficuly & prob when using vanitygen?

(Asked by: username_0 on 2016-07-27)

I am running this command

```
$ vanitygen64.exe 1abcdefg
Difficulty: 778316249440
[125.17 Kkey/s][total 39015067414][Prob 4.9%][50% in 46.3d]

```

1. What is it mean `Difficulty`? I understand that higher takes more time, but what is the scale, why it is different from total? Why alphabet is more difficult than only digits `vanitygen`1234567`?
2. What is it mean `50%` in 46 days, why it not tell me 100%. After 46 days, how much percent will be that it will complete in the next 46 days? If it is same reasons as in [Half-Life in nuclear physics](https://en.wikipedia.org/wiki/Half-life) I understand it.
3. The big question. What it is **`Prob 4.9%`**? `Prob` of what?

**Tags:** wallet, address, vanity-address, vanitygen

> **Comments:**
> **username_1**: General warning: use of vanity addresses is bad. Bad for yourself and bad for others you transact with. Address re-use is bad for privacy and safety.  
> **username_0**: I know. But it is for a gift. Giving someone BTC on his name, then he can use it once...  

---

## 1 answers

### Answer by username_2 on 2016-07-28. Score: 5 | Accepted answer

1. Difficulty tells you how likely it is that vanitygen will be able to find the address pattern you're looking for on the next guess. A value of 2n is twice as difficult (half as likely) than a value of n.
2. Because the process is completely random, it's impossible to give you a '100%' ETA. We can only estimate that, on average, you will find your key before some time period *half* the time (hence why 50% is used). Note that it re-adjusts the value to 75% once it hits that 50% mark (and re-adjusts again after hitting 75%, until the key is eventually found).
3. That is the likelihood that you would have found your key by *now*, from the time when you started generating your key.

> **Comments:**
> **username_0**: Thank you. Do you know why finding alphabet is more difficult that finding only digits address: `1abcdef` takes more time than `1123456`  

---

