The Ethereum Yellow Paper includes on page 6 in equation (44) a term \epsilon which contributes to the difficulty of a block. This term is added to the difficulty in equation (39).


\epsilon is an exponential function which depends on the length of the block chain only. The longer the chain up to the current block H_i, the higher \epsilon and \epsilon is growing exponentially.

This looks very strange. It would mean that the longer the chain, the higher the difficulty and the more difficult and costly it becomes to mine a new block. This is counter intuitive.

Does \epsilon really depend on the length of the block chain? Or is this a typo on in the paper and should it actually depend on something else, i.e. the gas limit H_l instead of the chain length H_i?

1 Answer 1


That portion of the difficulty adjustment formula is the difficulty bomb that will make mining proof-of-work increasingly more difficult to force miners to move to a proof-of-stake network.

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