<blockquote>
  <p>I have been reading a lot about this 10 minute block in the Bitcoin network. I'm slightly confused because I thought mining was a somewhat random process, mostly based on how powerful your mining facilities are.</p>
</blockquote>

<p>Correct, and because its random, its theoretically possible to mine the next block within seconds, it could even be the first hash you try. Its just probability, the 10 minutes is the <em>average</em> block time.</p>

<blockquote>
  <p>So if I had a quantum computer and could really churn through calculations, couldn't I mine a block faster than 10 minutes? Or is there something in the network taht would prevent me from submitting my mined block until 10 minutes had passed since the last mined block?</p>
</blockquote>

<p>This is somewhat unrelated to the randomness, because a more powerful computer can try more hashes anyway so is more likely to find a valid block sooner, yes. But this is the purpose of the mining difficulty. The difficulty changes once every 2016 blocks to keep the time roughly 10 minutes average. If blocks are mined too quickly, the difficulty will increase so it again takes 10 minutes on average.</p>

<p>Also note that quantum computers are a very unlikely threat to bitcoin mining. Quantum computers aren't just better at everything, there is quite a lot of hype around them without foundation :)</p>

CC BY-SA 3.0
2018-01-07T18:33:59.310Z
I shoudl have read your answer before I asked my other question to Nate, but I'll ask a follow-up here.  You said, "The difficulty changes once every 2016 blocks to keep the time roughly 10 minutes average."  So does that mean if the previous 2016 blocks were mined really quickly the difficulty target of the next 2016 blocks would be adjusted to try adn make teh average time of the 4032 (the quickly mined 2016 and the as yet unmined next 2016) most recent blocks mined 10 minutes?
Dave
CC BY-SA 3.0
2018-01-07T20:23:44.623Z
@Dave not quite, it would be adjusted so that the next 2016 are mined at 10 minutes average, it wouldn't try and compensate for the quick 2016
meshcollider
CC BY-SA 3.0
2018-01-19T10:32:05.677Z
But having said that, it is still possible that the next 2016 blocks may be mined in less than 10 minutes on average. Who knows, all the miners got lucky and found the right has quicker.
Suhas
CC BY-SA 3.0
2018-01-05T22:23:14.580Z
2018-01-05T22:23:14.580Z
meshcollider
<p>Yes (temporarily), but doing so would require a 51% attack, preferably just after the difficulty has been adjusted (at 51% the mining time for you would be an average of ~9:30 (9 minutes and 30 seconds) until the difficulty change which would happen in about a week in this case or another miner with a relatively small amount of control (2% would be fine, but let's say they have 5%) stops you from centralizing the network like Libra. If you want to do this PERMANENTLY, then (purely theoretically) mine 2^257 (or something like that) hashes per block. That particular number would decrease avg. time to 5 minutes.</p>

CC BY-SA 4.0
2019-06-26T14:09:46.887Z
Mining a block faster than 10 minutes has nothing to do with a 51% attack - blocks are mined faster than 10 minutes all the time
Raghav Sood
CC BY-SA 4.0
2019-06-26T14:11:41.780Z
I mean by “block time” average block time over a longer period (like a day in this case), not individual block times.
Number File
CC BY-SA 4.0
2019-06-26T14:13:41.120Z
Again, that has happened several times in the past, usually when someone brings a large chunk of mining power online quickly, before a difficulty adjustment period has completed - it does not require a single entity to have more than 51% of the hashrate, only for the average hashrate to be greater than the previous difficulty adjustment period had estimated
Raghav Sood
CC BY-SA 4.0
2019-06-26T14:15:04.217Z
I mean by my answer not just the entire network, but a single entity and the network.
Number File
CC BY-SA 4.0
2019-06-26T14:05:12.603Z
2019-06-26T14:14:02.537Z
2019-06-26T14:14:02.537Z
Number File
<p>Nope, nothing prevents it.  The actual time from one block to the next is random, and it very often happens to be less than ten minutes, just by chance.  </p>

<p>Ten minutes is the <em>target</em> time.  The block difficulty adjusts with the goal of having ten minutes be the <em>average</em> time between blocks.  Of course if the average is ten minutes, then you would expect some blocks to be faster and others slower.</p>

CC BY-SA 3.0
2018-01-06T00:18:36.650Z
Can you please share the statistical assumptions of that time? I guess the 10 minutes is a mean right? What is the rule to update the difficulty?
user_Lee
CC BY-SA 3.0
2018-01-06T07:38:17.620Z
The time between blocks follows a negative exponential distribution, with mean 10 minutes.
Pieter Wuille
CC BY-SA 3.0
2018-01-07T18:30:06.613Z
Where does the difficulty target come from?  Is that set by the Bitcoin algorithm, kind of like how the number of Bitcoins given as a reward halves every so often?
Dave
CC BY-SA 3.0
2018-01-07T18:35:46.577Z
@Dave: Yes, it's set by the algorithm.  It is calculated by a prescribed formula from the timestamps of previous blocks, which provide an estimate on the hash rate of the entire network.
Nate Eldredge
CC BY-SA 3.0
2018-01-05T22:23:36.693Z
2018-01-05T22:23:36.693Z
Nate Eldredge
<p>I have been reading a lot about this 10 minute block in the Bitcoin network.  I'm slightly confused because I thought mining was a somewhat random process, mostly based on how powerful your mining facilities are.  So if I had a quantum computer and could really churn through calculations, couldn't I mine a block faster than 10 minutes?  Or is there something in the network taht would prevent me from submitting my mined block until 10 minutes had passed since the last mined block?</p>

<blockchain><unconfirmed-transactions><block><mining-theory>
Could I theoretically mine a block faster than 10 minutes?
Dave
# Could I theoretically mine a block faster than 10 minutes?

(Asked by: username_0 on 2018-01-05)

I have been reading a lot about this 10 minute block in the Bitcoin network. I'm slightly confused because I thought mining was a somewhat random process, mostly based on how powerful your mining facilities are. So if I had a quantum computer and could really churn through calculations, couldn't I mine a block faster than 10 minutes? Or is there something in the network taht would prevent me from submitting my mined block until 10 minutes had passed since the last mined block?

**Tags:** blockchain, unconfirmed-transactions, block, mining-theory


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## 3 answers

### Answer by username_5 on 2018-01-05. Score: 4 | Accepted answer

Nope, nothing prevents it. The actual time from one block to the next is random, and it very often happens to be less than ten minutes, just by chance.

Ten minutes is the *target* time. The block difficulty adjusts with the goal of having ten minutes be the *average* time between blocks. Of course if the average is ten minutes, then you would expect some blocks to be faster and others slower.

> **Comments:**
> **username_6**: Can you please share the statistical assumptions of that time? I guess the 10 minutes is a mean right? What is the rule to update the difficulty?  
> **username_7**: The time between blocks follows a negative exponential distribution, with mean 10 minutes.  
> **username_0**: Where does the difficulty target come from?  Is that set by the Bitcoin algorithm, kind of like how the username_3 of Bitcoins given as a reward halves every so often?  
> **username_5**: @username_0: Yes, it's set by the algorithm.  It is calculated by a prescribed formula from the timestamps of previous blocks, which provide an estimate on the hash rate of the entire network.  

---

### Answer by username_1 on 2018-01-05. Score: 2

> I have been reading a lot about this 10 minute block in the Bitcoin network. I'm slightly confused because I thought mining was a somewhat random process, mostly based on how powerful your mining facilities are.

Correct, and because its random, its theoretically possible to mine the next block within seconds, it could even be the first hash you try. Its just probability, the 10 minutes is the *average* block time.

> So if I had a quantum computer and could really churn through calculations, couldn't I mine a block faster than 10 minutes? Or is there something in the network taht would prevent me from submitting my mined block until 10 minutes had passed since the last mined block?

This is somewhat unrelated to the randomness, because a more powerful computer can try more hashes anyway so is more likely to find a valid block sooner, yes. But this is the purpose of the mining difficulty. The difficulty changes once every 2016 blocks to keep the time roughly 10 minutes average. If blocks are mined too quickly, the difficulty will increase so it again takes 10 minutes on average.

Also note that quantum computers are a very unlikely threat to bitcoin mining. Quantum computers aren't just better at everything, there is quite a lot of hype around them without foundation :)

> **Comments:**
> **username_0**: I shoudl have read your answer before I asked my other question to username_5, but I'll ask a follow-up here.  You said, "The difficulty changes once every 2016 blocks to keep the time roughly 10 minutes average."  So does that mean if the previous 2016 blocks were mined really quickly the difficulty target of the next 2016 blocks would be adjusted to try adn make teh average time of the 4032 (the quickly mined 2016 and the as yet unmined next 2016) most recent blocks mined 10 minutes?  
> **username_1**: @username_0 not quite, it would be adjusted so that the next 2016 are mined at 10 minutes average, it wouldn't try and compensate for the quick 2016  
> **username_2**: But having said that, it is still possible that the next 2016 blocks may be mined in less than 10 minutes on average. Who knows, all the miners got lucky and found the right has quicker.  

---

### Answer by username_3 on 2019-06-26. Score: 0

Yes (temporarily), but doing so would require a 51% attack, preferably just after the difficulty has been adjusted (at 51% the mining time for you would be an average of ~9:30 (9 minutes and 30 seconds) until the difficulty change which would happen in about a week in this case or another miner with a relatively small amount of control (2% would be fine, but let's say they have 5%) stops you from centralizing the network like Libra. If you want to do this PERMANENTLY, then (purely theoretically) mine 2^257 (or something like that) hashes per block. That particular username_3 would decrease avg. time to 5 minutes.

> **Comments:**
> **username_4**: Mining a block faster than 10 minutes has nothing to do with a 51% attack - blocks are mined faster than 10 minutes all the time  
> **username_3**: I mean by “block time” average block time over a longer period (like a day in this case), not individual block times.  
> **username_4**: Again, that has happened several times in the past, usually when someone brings a large chunk of mining power online quickly, before a difficulty adjustment period has completed - it does not require a single entity to have more than 51% of the hashrate, only for the average hashrate to be greater than the previous difficulty adjustment period had estimated  
> **username_3**: I mean by my answer not just the entire network, but a single entity and the network.  

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