Crypto people make fun of me for making up passwords in my head, but my brain RNG has never been exploited, nor has anyone successfully Sherlock'd my password.
If it's long enough it's fine. They key property for passphrases is being able to remember them. But diceware phrases where you actually roll dice are stronger, and has evident verifiability.
RNG on computers is still hard, and a proper HSM has a carefully designed source of randomness and mixing. I'd trust Yubikey RNG mixing into Linux urandom much more than a random hardware wallet developer.
Yeah, something very cool is XOR can only improve randomness as long as there's no correlation between the sources. So Linux RNG XOR'd with this comment is even better than it's source!
Yes this has been a known problem of crypto/self custody since its inception. The 1 private key -> public key -> address is elegant but an horrible single point of failure.
When people create a wallet, the quality of the entropy and seed is always: I guess good, for now...
So far the only mitigation for that have been multi-signature but it has its own potential vulnerabilities.
My understanding is the next big Ethereum upgrade might include "Frame Transaction" [0] which will bring a "native multisig" capability to accounts so you can easily always have 2 addresses with different seeds origin to mitigate the risk.
- [0] https://forkcast.org/eips/8141/