I am developing a mobile wallet that supports multiple currencies (including Ethereum). As of now, it only supports one currency. The RPC wallet creation function for this currency returns a private key and public key for that currency wallet.
When I add more currencies (like Ethereum), I will have multiple private keys/public keys and would like all of them linked to a mnemonic/seed.
How would this be done? Can I create a custom seed and add private/public key pairs to it?
Or can I use my already existing private/public key pair to generate a seed?