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Ethereum consensus layer is constantly under attack, F2Pool have been doing this for the last 2 years

The BIS report that came out earlier this year highlighters some alarming problems regarding mining, and how miners could exploit their position and first-hand information to manipulate the market. It was theorized that 1 in 30 blocks mined was manipulated in some way shape or form. The whole thing is very similar to insider trading. And I have covered the BIS report in a previous post. Linked below if you want to take a closer look. It is a very interesting read. Now it has come to light that a new type of consensus layer attack has been taking place under our noses for at least the last two years.

What is a consensus layer attack

In the research paper recently released the researchers have come up with a way that one could theoretically attack and manipulate the consensus layer of a blockchain. The type of attack has been dubbed a "Unkle Maker". And what is a Unkle Maker? It is where you manipulate the timestamp of a block to allow you to mint the block instead of the competitor, making their block a Unkle Block.

An Uncle Block is created as a result of a tie between miners when they are able to solve the equation simultaneously. The tie is then resolved by looking at the difficulty of the blocks. The more difficult block is set at the Parent or main block, and the other Block becomes that Blocks Uncle. And the miner who mints the Parent Block also receives the reward for doing so.

Over time the block difficulty is naturally declining, meaning that they become easier and easier to mine. This is to prevent the Blockchain from coming to a complete stop due to unforeseen circumstances. The difficulty is also determined by the number of miners and artificially difficult increases. The Uncle Attack takes advantage of the natural decline in difficulty.

The way this is done is by manipulating the timestamps. If you just have had a difficulty decrease and you are able to set the times one second earlier, you then can count your block as it belonging to the higher difficulty. This means you then will be able to automatically win every tie for that block. And Miners have some leeway regarding the timestamps of blocks. This is not a problem as long as everyone is playing fair.


This is what a manipulated graf of mined blocks looks like, the is F2Pools number of blocked mined. Notice anything "odd"?

But surely no one is doing this type of thing, right? After having devices the possibility and how to execute it the researchers set out to look at an actual Blockhain to see if they could find proof of this actually taking place. They chose Ethereum as it is by far the biggest and most known of the Proof of Work Blockchains.

In walks F2Pool

The researcher looked at the blocks 12,000,000 to 15,226,042 to see if they could find proof of this type of Uncle Attack. And what they found was a resolute yes.

What they found was that the second largest mining pool, F2Pool, has been conducting this type of attack throughout the whole data set. And one of the researchers has been cited as saying they found proof of this going back for two years.

F2Pool appear to have executed this type of Uncle Attack on blocks a timestamp difference from their parents which is divisible by 9. So you can see in the tweet above the clear lack of Uncle Blocks during these timestamps. And the same goes for the picture above, also seen in the tweet.

And what makes this even worse is that F2Pool funder has during this time been complaining, unfounded, that their competitors were doing this type of thing to them. If you think this is a bit ironic and sounds familiar. It might be because Celsius's Founder And CEO Alex Mashinsky was doing a similar thing. Where he repeatedly was telling people to HODL the $CEL token while he was offloading as much f it as he could.

F2Pool's response to these allegations

F2Pools co-founder Chun Wang has responded to these allegations on Twitter and had the following to say:

basically what he is saying is that unless someone wants to change the blockchain. What is there, and they see no reason to change it. In a sense saying that they have been playing within the allowed rules. And in a second response, which actually had me shocked and stunned. Chun Wang had this to say:

This is probably the most savage tweet I have read, probably in all my time on Twitter. Not only is he taking pride in what they have been doing for the last two years. He then goes on bagging about virtually killing another crypto, $TRC, in a similar way back in 2013.

And as F2Pools are active on other coins, and not only on Ethereum. I can only assume that they have the same thing put into practice there as well. 

Chun Wang does however have a point in the last part. And that is basically don't hate the player hate the game. And I would argue that unless this is an Ethereum-only occurrence, which it looks not to be. Then this is definitely something that the other Proof of Work crypto needs to address. For Ethereum, I guess with the Merge being so close they can just say what is done is done and ignore it. But I do not see that as a possibility for any other crypto. 

And to have this bomb dropped on top of the likely chaos that will ensue after the Merge. It can not be fun times being a Proof of Work Crypto right now.

If you want to read my post on the BIS report, that highlights other problems regarding mining. The link to it is here: 

BIS report highlights alarming problems with mining, it could potentially get banned 


You will also be able to find a link to the whole Unkle Maker rapport, it is also worth to note the report is currently under peer review awaiting publication.

What are your thoughts on this whole situation? Do you think F2Pool can have clear continence because what they have done was technically not against the rules, or are they creating bigger problems for crypto as a whole by doing things like this? Please share your thoughts on this in the comment section down below.

If you would like to support me and the content I make, please consider following me, reading my other posts, or why not do both instead.


See you on the interwebs!




Picture provided by:, Midjourney 

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I am a patchy reader and writer of words... I also publish on Hive under @daje10

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