<p>"SPV mining" refers to a bad practice where a miner starts hashing a new block on top of an unverified parent block. If the parent block turns out to be invalid due to a double spend or newly activated soft fork, the new block will also be invalid.</p>

<p>The term SPV in this case is used because the miner only verifies the headers of the incoming block and then immediately starts mining the next block. </p>

<p>This has happened on main net before: when BIP66 activated in 2015, a short chain of blocks was mined on top of an invalid block that did not enforce the new rules. </p>

<p>This question may be a duplicate:</p>

<p><a href="https://bitcoin.stackexchange.com/questions/38437/what-is-spv-mining-and-how-did-it-inadvertently-cause-the-fork-after-bip66-wa#38439">What is SPV mining, and how did it (inadvertently) cause the fork after BIP66 was activated?</a></p>

CC BY-SA 4.0
2019-12-25T16:56:11.453Z
2019-12-25T16:56:11.453Z
pinhead
<p>Can anyone explain this simply? I am not finding enough explanation exactly on this type of attack. If possible, add some additional reading to your answer so that I can understand more.</p>

CC BY-SA 4.0
2019-12-25T08:31:20.067Z
I am not sure what exploit you are referring to. Perhaps this https://www.reddit.com/r/Bitcoin/comments/7752jc/trying_to_understand_spv_vulnerability_as_stated/ is relevant? A majority miner can inflate coinbase transaction and then spend those additional coins fraudulently with you - your SPV node just checks whether the chain is ok.
fiction
CC BY-SA 4.0
2019-12-25T17:58:34.640Z
Are you referring to this? https://medium.com/coinmonks/bdos-blockchain-denial-of-service-385c8c56b401?
Chris Chen
<blockchain><mining-theory><attack><block-validity>
What is the SPV Mining Exploit?
0xash
# What is the SPV Mining Exploit?

(Asked by: username_0 on 2019-12-25)

Can anyone explain this simply? I am not finding enough explanation exactly on this type of attack. If possible, add some additional reading to your answer so that I can understand more.

**Tags:** blockchain, mining-theory, attack, block-validity

> **Comments:**
> **username_1**: I am not sure what exploit you are referring to. Perhaps this https://www.reddit.com/r/Bitcoin/comments/7752jc/trying_to_understand_spv_vulnerability_as_stated/ is relevant? A majority miner can inflate coinbase transaction and then spend those additional coins fraudulently with you - your SPV node just checks whether the chain is ok.  
> **username_2**: Are you referring to this? https://medium.com/coinmonks/bdos-blockchain-denial-of-service-385c8c56b401?  

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## 1 answers

### Answer by username_3 on 2019-12-25. Score: 2

"SPV mining" refers to a bad practice where a miner starts hashing a new block on top of an unverified parent block. If the parent block turns out to be invalid due to a double spend or newly activated soft fork, the new block will also be invalid.

The term SPV in this case is used because the miner only verifies the headers of the incoming block and then immediately starts mining the next block.

This has happened on main net before: when BIP66 activated in 2015, a short chain of blocks was mined on top of an invalid block that did not enforce the new rules.

This question may be a duplicate:

[What is SPV mining, and how did it (inadvertently) cause the fork after BIP66 was activated?](https://bitcoin.stackexchange.com/questions/38437/what-is-spv-mining-and-how-did-it-inadvertently-cause-the-fork-after-bip66-wa#38439)


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