Problem: not possible to cancel SendToEthereum transactions

[thomas-nguy]

Implement a new events in the EVM hooks to be able to cancel an "unbatched" transaction.

Critical points are:

• Verify the sender address and allows to unbatch only transactions related to him.
• Contract needs also to refund the user if it is successfull

[yihuang]

Maybe with the eip-712 feature in ethermint now, we don't need to add these events anymore, instead ask the client to sign a cosmos message directly using metamask.

[thomas-nguy]

hmmm with our current design, cosmos native tokens are still managed by the smart contract. We cannot use EIP-712 without major architecture change.

[yihuang]

hmmm with our current design, cosmos native tokens are still managed by the smart contract. We cannot use EIP-712 without major architecture change.

I see, currently, the internal MsgSendToEthereum's sender is the contract, if we transfer the native token to user first, we can set the sender to the user. But then when the user cancels the msg, he'll be left with the native tokens, need another action to move it back to erc20 again. maybe indeed make sense to add a cancel event for it since we are already here.
Is it possible to do a major architecture change right now though, are the related frontend support already done?

[thomas-nguy]

I think it is still possible the change the architecture but we might consider that we have a lot of tokens already bridged
(CRO + solo machine bridged tokens + cosmos tokens)

But we can spend some time to think about a better architecture