<p>An inflation bug is one which allows an attacker to print new money, beyond what is permitted by the subsidy rule (50 BTC per block during the first 210000 blocks, 25 BTC the next 210000 blocks, 12.5 BTC in the 210000 blocks after that, etc.).</p>
<p>This may take several shapes:</p>
<ul>
<li>Allowing a malicious miner to introduce more coins than the subsidy rule allows in a block.</li>
<li>Allowing an attacker to construct a transaction that is unbalanced (has more in output values than in input value).</li>
<li>Any bug that would permit an attacker to construct UTXOs out of nothing.</li>
</ul>

CC BY-SA 4.0
2022-05-31T00:37:23.363Z
2022-05-31T00:37:23.363Z
Pieter Wuille
<p>I often hear that the worst bug that could impact bitcoin is an inflationary bug.</p>
<p>But what exactly is meant by 'inflationary bug'?</p>

<bitcoin-core><protocol><doublespend>
What is an inflationary bug in the context of bitcoin?
StatsScared
# What is an inflationary bug in the context of bitcoin?

(Asked by: username_0 on 2022-05-31)

I often hear that the worst bug that could impact bitcoin is an inflationary bug.

But what exactly is meant by 'inflationary bug'?

**Tags:** bitcoin-core, protocol, doublespend


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## 1 answers

### Answer by username_1 on 2022-05-31. Score: 4 | Accepted answer

An inflation bug is one which allows an attacker to print new money, beyond what is permitted by the subsidy rule (50 BTC per block during the first 210000 blocks, 25 BTC the next 210000 blocks, 12.5 BTC in the 210000 blocks after that, etc.).

This may take several shapes:

* Allowing a malicious miner to introduce more coins than the subsidy rule allows in a block.
* Allowing an attacker to construct a transaction that is unbalanced (has more in output values than in input value).
* Any bug that would permit an attacker to construct UTXOs out of nothing.


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