Bitcoin Forum

My wallet.dat's filesize was 70 KB.

I encrypted it with bitcoin-qt.

Then it was 53 KB.

How can I verify that it's encrypted properly?

Assuming I have a very secure password, it's safe for me to widely distribute my new, encrypted wallet.dat, right?

You should download truecrypt and make an encryption volume. The bitcoin-qt encryption is very basic.

If you have enough BTC in that wallet to worry about the encryption holding up, you should be worried about your computer getting compromised. Get a linux livecd or make a bootable usb, boot up, make a paper wallet while offline. Encrypted, if you prefer. Never let the private key touch an online system until you want to spend the coins. Brownie points for signing the transaction offline when you do decide to spend.

Many encryption procedures I've seen compress the file first.

It rebuilds the file which compacts it by removing housekeeping space that BDB kept around. It should almost always be smaller.

I wouldn't advise it. You'll reduce your security from two factor to one factor... and the encryption doesn't protect your privacy it only prevents spending/signing. Also, the wallet will eventually go out of sync once you've used up the keypool.

Citation needed. I understand it's AES with a variable number of rounds. The weakest part in the wallet's encryption is your passphrase.

Aye, compression reduces redundancy making it more difficult to break encrypted data.