Hi @sauliusgrigaitis ! I'm interested in working on this. I have worked with BLS signatures before and would love to give this a try. Can you please assign this to me and give me an idea on how I should get started?

@shreyas-londhe We usually do not assign issues to external contributors because external contributors rarely finish tasks. The best is to simply signal here that you are working on the issue by posting a link to your branch. Then it's unlikely that someone else will start working on it if you already have decent progress.

So the idea would be to do something like rust-kzg. rust-kzg supports multiple ECC backends for EIP-4844 functionality. However the problem with rust-kzg is that in order switch ECC backend you need to change the crate (for example change from rust-kzg-blst to rust-kzg-arkworks). We can maybe start with something like this for our bls crate. So we could have bls-blst, bls-zkcrypto etc. and just manually switch the dependency.

However, for the long-term solution, I would prefer that we have an option to switch at runtime (let's say with some command line flag) without a need to recompile the client. But if we will have to switch at the runtime - then I also would like to make optional backends via Rust features. This would allow to disable at compile time some of the ECC backends in tricky situations (for example if ECC backend doesn't support particular compilation target).

Thanks for the detailed explanation @sauliusgrigaitis ! I'll get started on this and make a draft PR in a few days.

One thing I forgot to mention - we now are coupled with BLST types, it would be nice to be able to compile Grandine without BLST completely (when using a different ECC library). This would help with the exotic targets where BLST doesn't compile.