More Secure Private Keys / Brainwallet

[IveBeenBit]

Keep in mind I'm wet behind the ears cryptographically speaking. So I was thinking today....very soon I'm going to be setting up a brain wallet. I will use the SHA256 hash of a passphrase....probably words pulled at "random" from a dictionary (correct horse battery staple).

It occurred to me that to make it extra secure against brute force attacks, I could get the hash of all those words except 1 of them, then append that one word to the SHA256 hash of the others. Is this a good idea? Is this what people talk about when they refer to a "salt?"

Example:

SHA256 (Barack Obama) = d8f758500c5d3303786d5638bb720775769f52064dfb669d3540ac9074acf30e

But that would get busted wide open by a dictionary attack in short order, I'm guessing.

So let's do....
SHA256 (Barack) = 891bd7ecb4ef7e1a70bec2585132036929dd0d1262674a44ec531a916715e7f4

and then...

SHA256 (Obama891bd7ecb4ef7e1a70bec2585132036929dd0d1262674a44ec531a916715e7f4) = a0bb198d05696ba0addfea88489e75d42ef8b5bf7bfcdf68df9dccb70f231832

So my for my private key I would use a0bb198...1832

Is this a good idea?

[rjk]

That sounds reasonable as long as you choose unrelated words and throw in a few random symbols for good measure.