EVM key derivation

[PatrickGeyer]

I would like to use EVM for escrows in nostr flows. To do so, I need to derive EVM private and public keys from a nostr private key, and would also need to derive an EVM address for a given nostr public key without having access to the corresponding private key - if the protocol should stay as non-interactive as possible.

Is there a way of doing this safely?

[mikedilger]

There are cryptographic key derivation functions (KDF) you can use where you put in some secret and maybe some well defined extra input and out comes a key. For example SHA256(SHA256(privatekey) + "key1")

I'm not a cryptographer and there might be safer ways than that simple example. I would search for KDFs

Be aware that there are password-based KDFs which are not what you are looking for (pbkdf2, scrypt, argon2, bcrypt)... these stretch a password into a key using expensive and slow functions in order to foil rainbow table creation. But you don't need that if you are starting from key material.