<blockquote>
  <p>m*G</p>
  
  <p>bc &lt;&lt;&lt;
  “73111678085084231450767103284505018606851115862905010375565411946552667932016
  * 41313771436092106966070828753784402438291933698697412643075684398900444625545”</p>
</blockquote>

<p>Careful, G is a secp256k1 elliptic curve generator point. You cannot multiply it as you would a scalar. You need a secp256k1 library to perform scalar x EC-Point operations.</p>

CC BY-SA 4.0
2019-01-29T21:32:07.837Z
I suggest you try a command line tool, such as Libbitcoin-BX for EC-point operations in command line: https://github.com/libbitcoin/libbitcoin-explorer/wiki/bx-ec-to-public
James C.
CC BY-SA 4.0
2019-01-29T21:36:54.757Z
thanks james, I'd like to do without library if possible
monkeyUser
CC BY-SA 4.0
2019-01-29T21:41:42.097Z
that library is very powerful, with `bx ec-to-public 5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89` I can find Public Key compressed, But i'd like to use even `A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570` and understand how it works
monkeyUser
CC BY-SA 4.0
2019-01-29T21:44:03.150Z
Have a look at the operations necessary for scalar x EC point operation, it's pretty complex with just basic CL tools: https://en.wikipedia.org/wiki/Elliptic_curve
James C.
CC BY-SA 4.0
2019-01-29T21:45:17.793Z
Yep you are right :)
Thanks again James for your time
monkeyUser
CC BY-SA 4.0
2019-01-29T21:31:05.570Z
2019-01-29T21:31:05.570Z
James C.
<p>I have that result after hash_pbkdf2</p>

<pre><code>5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570
</code></pre>

<p><a href="https://i.sstatic.net/A0K36.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/A0K36.png" alt="enter image description here"></a></p>

<p>left 256 bits are:</p>

<pre><code>5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89
</code></pre>

<p>in base 10 are</p>

<pre><code>m = 41313771436092106966070828753784402438291933698697412643075684398900444625545
</code></pre>

<p>right 256 bits are</p>

<pre><code>A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570
</code></pre>

<p>in base 10 are</p>

<pre><code>G = 73111678085084231450767103284505018606851115862905010375565411946552667932016
</code></pre>

<p>To calculate Master Public Key I have to do</p>

<pre><code>m*G

bc &lt;&lt;&lt; “73111678085084231450767103284505018606851115862905010375565411946552667932016 * 41313771436092106966070828753784402438291933698697412643075684398900444625545”
</code></pre>

<p>result </p>

<pre><code>3020519157716314193817478999423070077945694756523017007189820738431399197829981163447928137705627795431573290757393848092663806903883822516032876636948720
</code></pre>

<p>that result is not correct</p>

CC BY-SA 4.0
2019-01-31T00:58:10.960Z
See https://bitcoin.stackexchange.com/questions/84116/get-master-private-key-from-bip39-seed.
skaht
<hash><public-key><mastering-bitcoin>
Create master public key after HMAC-SHA512
monkeyUser
# Create master public key after HMAC-SHA512

(Asked by: username_0 on 2019-01-29)

I have that result after hash\_pbkdf2

```
5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570

```

[![enter image description here](https://i.sstatic.net/A0K36.png)](https://i.sstatic.net/A0K36.png)

left 256 bits are:

```
5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89

```

in base 10 are

```
m = 41313771436092106966070828753784402438291933698697412643075684398900444625545

```

right 256 bits are

```
A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570

```

in base 10 are

```
G = 73111678085084231450767103284505018606851115862905010375565411946552667932016

```

To calculate Master Public Key I have to do

```
m*G

bc <<< “73111678085084231450767103284505018606851115862905010375565411946552667932016 * 41313771436092106966070828753784402438291933698697412643075684398900444625545”

```

result

```
3020519157716314193817478999423070077945694756523017007189820738431399197829981163447928137705627795431573290757393848092663806903883822516032876636948720

```

that result is not correct

**Tags:** hash, public-key, mastering-bitcoin

> **Comments:**
> **username_1**: See https://bitcoin.stackexchange.com/questions/84116/get-master-private-key-from-bip39-seed.  

---

## 1 answers

### Answer by username_2 on 2019-01-29. Score: 0 | Accepted answer

> m\*G
>
> bc <<<
> “73111678085084231450767103284505018606851115862905010375565411946552667932016
> \* 41313771436092106966070828753784402438291933698697412643075684398900444625545”

Careful, G is a secp256k1 elliptic curve generator point. You cannot multiply it as you would a scalar. You need a secp256k1 library to perform scalar x EC-Point operations.

> **Comments:**
> **username_2**: I suggest you try a command line tool, such as Libbitcoin-BX for EC-point operations in command line: https://github.com/libbitcoin/libbitcoin-explorer/wiki/bx-ec-to-public  
> **username_0**: thanks username_2, I'd like to do without library if possible  
> **username_0**: that library is very powerful, with `bx ec-to-public 5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89` I can find Public Key compressed, But i'd like to use even `A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570` and understand how it works  
> **username_2**: Have a look at the operations necessary for scalar x EC point operation, it's pretty complex with just basic CL tools: https://en.wikipedia.org/wiki/Elliptic_curve  
> **username_0**: Yep you are right :) Thanks again username_2 for your time  

---

