Only better way is to replace the password with the hash of a biometric scan (fingerprints maybe) but in this way cost are higher and not all devices can support it.
Biometric scans, AFAIK, are like images. Different scans of the same individual will produce different data, which would produce different hashes
You're true for a hash of the full image, but fingerprint scanner actually save only a "path" of the minutiaes of the fingerprints. And using that work in a reliable way.
. You can compare different images to see if they belong to the same person, but if you use one of these images as an encryption key, there's no guarantee you'll ever be able to unencrypt your data.
I didn't mean use the hash as password but only as authentication method.
Of course that biometric scans could be used as an authentication method by a sophisticated device, but if the device is "physically hacked" and the biometric check is bypassed, you'll need something else to protect the data.
And, honestly, if you're afraid of physical thefts, shouldn't you also be afraid of physical coercion? What good is a biometric scan if the thief can simply force you to put your finger/eye/whatever?
As slush said before, we are not at the point where this is a reasonable threat for most of us. Hackers are a serious threat though, so we should first focus on how to protect ourselves from them first.
On that I agree totally with you: my reply was to luicon who had expressed concern about forgetting the password. If one can obtain access to both you and the device there is really few things to do.
BTW to avoid physical coericion there is a way, even not too difficult to implement: some times ago I've a phone with an encrypted area in which store password and pins. If you input the good password you decrypt the area, if you put a wrong one you obtain an error, but if you put a "special" one you go into a fake area with other data. Maybe is possible, for extra-paranoid implement a similar approach: one pin for real wallet, another one for another with only few BTC in it.
But again we are talking of extra-paranoid people here. IMHO slush design is more than adeguate.