[matharmin]

There is no way for the attacker to know how many keys you have. So you can give the attacker 2 keys, while you have your actual sensitive data behind the 5th one.

It could still be a challenge to convince the attacker that you really only had n-1 keys, so you may need to include plausibly-sensitive data in earlier layers.

[hartator]

Hum, it the attacker knows that he wants the key for a specific secret, like a Bitcoin wallet, can he just torture you until he gets it?

[istjohn]

Well, yeah. There's no system that will defeat rubber hose exploits.

[p_j_w]

Sure, but there's a significant subset of attackers for whom this isn't an option. For example, I live in the USA. Torturing me because the government thinks there's a 7th key I'm not being up front about isn't an option for them, at least on paper.

[j_walter]

Have a different and much smaller bitcoin wallet that serves as a decoy...and have the keys in the 1st layer of encryption.