To think of it, torturing is way worse than surrendering your crypto. Getting maimed/ killed just to protect your crypto is just too scary.
If you are in the situation of the "$5 wrench attack", there is also nothing stopping the attacker from forcing you to log in to your online banking or reveal your credit/debit card PINs and clearing out all your fiat as well.
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Deniable plausibility only works as long as it is deniable. A hidden and encrypted OS behind a password is no more secure
per se than a hidden wallet behind a passphrase on a hardware wallet, provided you set them both up correctly and there is no way to prove they exist.