Login widget that uses a altcoin wallet (Metamask-like login functionality)

[newlymintedcryptolover]

Hi everyone,

I'm trying to figure out if it's possible to create a login widget that would use an altcoin wallet. It'd work somewhat similarly to how logging in with Metamask works - a user would authenticate with their altcoin wallet, confirm the nonce and get logged in to the website.

Any ideas on how to do that?

Thanks in advance! 

Sincerely,