Recipe for Application Crypto

[JoshOrndorff]

When would I ant to add a key type? One example is adding or removing grandpa. When would a pallet that doesn't cross the wasm boundary do it? Would it?

[4meta5]

I came across this great overview of the three levels to account crypto:

• Pair (for creating transactions)
• Public (always derivable from Pair through the associated type Verify::Signer, and in the case of SECP256k1/ECDSA, also from a valid Signature with the ECDSA Recover opreation)
• AccountId (always derivable from Public using IdentifyAccount::AccountId)