The very early bitcoin wallets used HKDF-type constructions (for every address belonging to a wallet) but then all crypto wallets moved to a construction where every address shared an ECC mathematical relationship – for good reasons such as the ability to create view-only wallets.
My question is what happens if ECC is broken or a cryptographically relevant quantum computer arrives, will it be able to discover relationships between addresses in a wallet given one or more address belonging to a wallet?
For example, it will be able to obtain the private keys of any revealed public key belonging to a particular wallet, would it then be able to derive the master private key of the wallet? Would it be able to attribute other public keys to the same wallet?
