<p>First of all, when 1 second has passed, the miner can just increment the timestamp in the header. This already gives us 4 Ghash/s rather than 4 GHash/block.</p>

<p>When this is not enough, and the nonce range is exhausted before a second has passed, the miner builds a new proposed block with a hash to search through. Specifically, the very first transaction in the block (the coinbase, which also receives the subsidy and fees) has a 100-byte area that essentially contains arbitrary data. So miners use this area as an 'extra nonce'.</p>

CC BY-SA 3.0
2014-11-27T17:30:55.703Z
2014-11-27T17:30:55.703Z
Pieter Wuille
<p>In the mining process, everytime a block has to be confirmed, a certain hash with an incremental nonce is generated: If the nonce is a 32 bit number it can assume a value between 0 and 2^32 - 1. It gives about max 4.000.000.000  attempts on the same block to find the right hash. But if the target begins with 13 zeroes why isn't 2^32 too little to find the correct hash?</p>

CC BY-SA 3.0
2016-03-16T10:44:18.900Z
related: [How can we be sure that a new block will be found?](http://bitcoin.stackexchange.com/q/22978/5406)
Murch
<coinbase-transaction><mining-technical-details><nonce>
Has the nonce used in mining been sized?
nglpx1
# Has the nonce used in mining been sized?

(Asked by: username_0 on 2014-11-27)

In the mining process, everytime a block has to be confirmed, a certain hash with an incremental nonce is generated: If the nonce is a 32 bit number it can assume a value between 0 and 2^32 - 1. It gives about max 4.000.000.000 attempts on the same block to find the right hash. But if the target begins with 13 zeroes why isn't 2^32 too little to find the correct hash?

**Tags:** coinbase-transaction, mining-technical-details, nonce

> **Comments:**
> **username_1**: related: [How can we be sure that a new block will be found?](http://bitcoin.stackexchange.com/q/22978/5406)  

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## 1 answers

### Answer by username_2 on 2014-11-27. Score: 7

First of all, when 1 second has passed, the miner can just increment the timestamp in the header. This already gives us 4 Ghash/s rather than 4 GHash/block.

When this is not enough, and the nonce range is exhausted before a second has passed, the miner builds a new proposed block with a hash to search through. Specifically, the very first transaction in the block (the coinbase, which also receives the subsidy and fees) has a 100-byte area that essentially contains arbitrary data. So miners use this area as an 'extra nonce'.


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