<p>It really depends on how much of the private key you're missing. Every missing byte increases the search space by a factor of 256. Assuming you can search one million keys every second (a reasonable approximation for a modern CPU utilizing all its cores running a decently optimized search algorithm):</p>
<ul>
<li>4 missing bytes, 2<sup>32</sup> = 4,294,967,296 keys, about 1 hour to search through</li>
<li>5 missing bytes, 2<sup>40</sup> = 1,099,511,627,776 keys, about 12 days to search through</li>
<li>6 missing bytes, 2<sup>48</sup> = 281,474,976,710,656 keys, about 8 years to search through</li>
</ul>
<p>As you can see, the chances of recovering the rest of the key within a reasonable timeframe fall pretty quickly. If there's a lot of funds to recover you can of course spend funds on acquiring more computing power, but even increasing it 256 times still offsets just one missing byte.</p>

CC BY-SA 4.0
2024-05-25T06:52:01.503Z
Thankyou. I will ponder my next step
Jonathan
CC BY-SA 4.0
2024-05-24T23:16:12.743Z
2024-05-24T23:16:12.743Z
Vojtěch Strnad
<p>I have only a partial private key due to hard drive damage. I have the full public key I plan to extrapolate back on the secp256k1 elliptic curve to locate the full private key. What are my chances of getting it correct?</p>

<private-key><recover-private-key><elliptic-curve>
Obtaining other portion of my private key
Jonathan
# Obtaining other portion of my private key

(Asked by: username_0 on 2024-05-24)

I have only a partial private key due to hard drive damage. I have the full public key I plan to extrapolate back on the secp256k1 elliptic curve to locate the full private key. What are my chances of getting it correct?

**Tags:** private-key, recover-private-key, elliptic-curve


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## 1 answers

### Answer by username_1 on 2024-05-24. Score: 0 | Accepted answer

It really depends on how much of the private key you're missing. Every missing byte increases the search space by a factor of 256. Assuming you can search one million keys every second (a reasonable approximation for a modern CPU utilizing all its cores running a decently optimized search algorithm):

* 4 missing bytes, 232 = 4,294,967,296 keys, about 1 hour to search through
* 5 missing bytes, 240 = 1,099,511,627,776 keys, about 12 days to search through
* 6 missing bytes, 248 = 281,474,976,710,656 keys, about 8 years to search through

As you can see, the chances of recovering the rest of the key within a reasonable timeframe fall pretty quickly. If there's a lot of funds to recover you can of course spend funds on acquiring more computing power, but even increasing it 256 times still offsets just one missing byte.

> **Comments:**
> **username_0**: Thankyou. I will ponder my next step  

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