Vladimir, how easily could you crack a WinRAR archive with a strong password?

Useful info!

But how about using something like AxCrypt? This allows you to encrypt individual files without messing around with images or mounting/dismounting. For the super paranoid I guess you can RAR or ZIP up the bitcoin dir and password protect the archive and then encrypt it with AxCrypt.

Sweet..this saves me the extra step of encrypting my wallet.dat before I upload it to Dropbox..hmm..or I can copy the encrypted file to both for extra redundancy :p

Wouldn't you just need to copy the wallet with your savings account once? If you send all the bitcoins you want to keep in savings to that one address, you should always be able to restore it in the future even if you only had the initial copy of the wallet. Am I wrong?

Couple of questions:

1) Is TrueCrypt disk encryption superior to encrypting a single file with 7z or something and why do you prefer TrueCrypt above the alternatives?

2) How many characters would you use for the password? I hear that ideally the password should have 128 bits of entropy and that unicode characters have more entropy than ascii, is this true?

3) If you were extremely wealthy, would you prefer storing your bitcoins in a single address or spread it out evenly over 100 addresses, making it 100 times more likely for a collision to happen but only being able to lose 1% of your wealth at a time?

One very important addition - make sure that the private key is only, ever entered on an "absolutely secure" computer.
I am "reasonable sure" that my home computer is free of keyloggers, but not absolutely sure. I plan to format a new computer, and only use it for bitcoin - this way I'm "almost absolutely sure" it has no keyloggers installed.

Three scenarios that I think of separate "almost absolutely sure" from "absolutely sure":
1. The OS image I'm using contains a hidden keylogger.
2. Bitcoin itself contains a keylogger.
3. My hardware/firmware contain a keylogger.

Out of these, I'd say #1 is the most likely, and if I choose my OS image well, I can reduce that to "not bloody likely" as well.

it's easy to do this if you can parse wallet.dat yourself. but without doing that, there ought to be a relatively straightforward way to do what you want: 

keeping the 'large' wallet off of the public internet, connect a new, private, uncompromised node to it alone and make an ip-address (public key) payment of the smaller amount you want to spend. then disconnect the 'large' wallet's node, connect the recipient's node to the public internet, confirm the receipt, and spend the coins from there.

obviously you can't spend coins without attaching something to the network at some point, but the goal is to segregate your large holdings from the public internet.

if this method is too complicated, you could of course generate arbitrarily many private wallet.dat files and store small amounts in each of them, then move them over one by one. it wouldn't be hard to write better software tools to avoid the need for these steps, though.

Quick question, if I create a back up, can I send Bitcoins to that address 100 times before I have to update it or is it that I can create 100 new personal addresses before it have to update it.

Thanks

Had a quick question,

I did all the true crypt and set up an image.   I put all my data/bitcoin folders inside.   I made a copy and placed one on my storage drive and one on my flash drive.

I then put my flash drive away.  Afterwards I mounted my image from the C:\ drive and received some bit coins.


If my computer crashes do I lose those bit coins?  Or can I bring out my flashdrive and it will also receive those coins?


Thanks.

If you're only doing it as a backup, you only need to back up one file: wallet.dat

However you should probably encrypt it with something like True Crypt first before uploading online.