Quote from: larry_vw_1955 on Today at 06:04:33 AM

Well I don't know if I could agree with that.It all depends on the passphrase. If the passhprase has enough entropy then it is just as secure as a bitcoin address you would generate by throwing dice.

Only a 128 bit entropy entered into a cryptography function can provide the same security as a randomly generated private key. Human beings are terrible at memorizing things in general and they are even worse when the length of what they have to memorize is too long.
In other words the whole idea for a brainwallet is moot if you are using such a big entropy.

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But just for the sake of argument, to your way of thinking, how many hashes would make it become "safe"?

There is no easy answer to this. But for your information we are currently computing 165 exa double_SHA256 hashes in bitcoin mining. That is:

Code:

165,000,000,000,000,000,000