Interface that allows token transfer to various EVM chains using QR Code
We have an idea of multi chain wallet with possibility to send and receive money with just scanning a QR code. If there is any possibility it should be integrated with fiat currency as well. Basically a futuristic wallet where user doesn't care what blockchain he is using, everything should be taken care by the wallet. Even if we cannot build it completely in the hackathon we can try to make this a good start at hackathon by trying to at least build basic blocks for that. To give an example idea is to build something like apps called paytm, phonepe, gpay in india. Main idea is, users can send transactions such as token transfers to multiple EVM chains with one wallet. And users send their tokens to the relayer, and the relayer can pay the user's gas fee instead. It is currently hard-coded, but we plan to apply it through a price oracle soon. This demo only covers ERC20, but NFT is also possible. There are several problems to be addressed. Transactions can be reused and abused even if the user doesn’t want. We try to solve this problem through nonce or block height. Another problem is that relayers can drop transactions. This will require further consideration in the future.
How it's made
We utilized most of the ideas of EIP-2462. (https://github.com/hsy822/eip2462-sample) In the demo, only ethereum chain and polygon chain are implemented, but it was confirmed that it works with celo, klaytn, etc. through the eip-2462 sample site. (https://hsy822.github.io/eip2462-sample/) It is a natural design to separate the relayer part into the backend, but it was implemented simply by hardcoding it in relation to time.