From my standpoint I find blockchain.info with 2 factor authentication and a second password for sending coins to be very secure and reliable.
This is not the same as other web wallets.
Online wallets are NEVER SAFE assuming so is asking for problems.
to OP.
- Make sure to have multiple wallets. (multiple different wallet.dat files with different passwords - watch out with passwords on wallets not often used, password lost is money gone)
- Best to store these wallets on a pc not connect to the internet. (USB sticks are also possible, also easy to put in a vault, if you use USB sticks make sure to know the best practices (boot pc from livecd, and only then put in the USB stick, not on regular windows.)
- Always have at least one backup, multiple are preferable. (make sure to regularly make new ones, always make a backup before updating your wallet software)
- Paper wallets are a blessing, they are now pretty easy to create, see above. Advantage, you can print the paper wallet out, and check whether or not it works. (make sure to do this on a PC not on the internet, preferably on a livecd. When a paper wallet is created you get a private key, you can import this into a wallet client. This allows that wallet client to sign any message with its key. When you copy that into another wallet client, and give it the public key, it can verify it and say whether or not it is correct. It is still advised to first send a small amount to the wallet, and have it show up on the blockchain. It is
not recommended to actually send something with the paper wallet. The one thing to keep in mind with a paper wallet, is that you should use them as being discardable. So when you want to move some money off your paper wallet on to your hot wallet, you got to keep in mind to send the remaining amount to a new paper wallet. (new paper wallet is new private key, so no chance anybody can do some peeking)
When I started my paper wallets, I made sure to put detailed instructions with them, as I know that some of them I won't touch for 10+ years, I highly recommend it.
- Then last but not least you also have multi-signature walllets, but thats another big world. (for example you would need 2 keys to move funds)
This is the short, not very paranoia version. You can make this as complex as you want. It is however important to understand the whole thing,
- computers get hacked, accept this and take precaution.
- passwords get lost, take precaution.
- hard drives fail, take precaution.
- houses catch on fire, take precaution.
- stuff gets thrown out accidentally, take precaution.
- people have accidents (unfortunately) accept this and take precaution.
I most likely could add another 100 things to the second list, but I expect the idea to be pretty clear, backups have never been so important for anything.
We usually have insurance for a lot of these things, bitcoin doesn't. (yet?) This means that any failure/mistake by the user gets punished fairly harsh, the money is gone. (or at least can be) All the possible steps you can take to prevent this, dozens if not hundreds of topics on these forums. It has been getting better, but unfortunately we are not completely there yet.
