The merge & EIP 3675

The merge from Eth1 to Eth2 will come soon, but with such a massive change, there will be many issues that pop up. This EIP covers not only the merge itself, but also changes made to make sure this as smooth as possible.

What if the PoS chain gets linked onto a minority fork?

This could happen if the block number was hard coded into the EIP and a malicious miner created a fork by proposing the exact block number on a transaction and it would be a mess.

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https://preview.redd.it/ni9bcbzludg71.png?539&format=png&auto=webp&s=aa205722e0a801d43910dc7108ec73c0d3db1fb4

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Thankfully, we don't have to worry about this as it's the difficulty that is hard coded into the EIP that determines when the terminal PoW block gets mined and when the first PoS block (the transition block) begins.

What about existing smart contracts?

As part of the upgrade, several opcodes will be deprecated, and new ones added in.

One notable deprecation that will affect quite a few contracts is the difficulty opcode, which will be set to 0.

Another area of concern is randomness. If your smart contract relied on block hash for pseudo-randomness, it's even more insecure under PoS since block proposers can change the block number.

We're just as excited as you are about the merge, so follow us for more threads like these. Thanks to u/EthCatHerders and u/mkalinin2 for the info and the image this thread was based on: https://youtu.be/zNIrIninMgg

Here's another resource: https://eips.ethereum.org/EIPS/eip-3675