Bitcoin Forum

I'm fairly tech savvy and my stash is only modest in size I think.  I currently use Blockchain wallet with offline encrypted keys in multiple redundant locations.

But I'll be honest I'm still nervous about the setup. 

Is there a reputed online bank that will store and insure my bitcoins?  I'd be happy to pay a modest fee for that security and peace of mind.

No.

Hold them yourself.

Printing out private keys and burying them is one way.


If you have any bitcoin with a third-party holder, make sure that it is an amount that you can afford to lose.

And there were people saying that bitcoin will kill all banks....:)

Can anyone specifically elaborate on blockchain.info and any potential weak points?

OP you may be a little overanxious. stroke that boner and let the tension die down.

The safest thing you can do is use bitaddress.org to generate some paper wallets, print those out, then send your coins to the *LOAD & VERIFY* address.  This will pull all your coins offline, onto paper, and you can literally stick them in a drawer, or in a safety deposit box at a bank.  This is the best way.  (If you want to be even more secure, to go bitaddress.org, click the "Github Repository" link bottom right, then on bottom right of that page, click "Download ZIP".  Double click the main file in there, and it will load up the bitaddress.org website page *offline*.  Turn off your internet connection completely.  Generate Paper Wallets.  Print them.  Close the webpage.  Restore your internet connection.  If you want to be even more secure, do this on a laptop with a freshly installed operating system that has never been online.  Pull the zip file over to that laptop on a USB drive and load it up there.  This way you've never been online, and you're generating keys completely secure.  Print.  Done.)  

From all I've read, this is the only safe way to store your coins.  When you are ready to spend, you'll need to import them into BitcoinQT software, so its good to have that on hand.  Install it, and give it the 7 hours or so to download the whole blockchain record.  When you're ready to pull your coins into the wallet software and move them or spend them:  Bitcoin QT > Help > Debug Window > Console Tab >
Type this:  importprivkey typeyourlongassprivatekeyaddresshere "AnyLabel"  (no quotes)
Hit Enter.  Give it about 5 - 10 solid minutes to import fully.  Then you'll see your coins in Bitcoin QT and you can send out.
If you encrypted your paper wallet follow instructions here:  https://en.bitcoin.it/wiki/How_to_import_private_keys_v7%2B


Its bad advice to store any coins online, on any website.
I recommend the paper wallet method above.  
I know people with hundreds of thousands of dollars in bitcoin and they use that method for security reasons.

Take the printouts and make multiple copies before you close the web page that generated them.  Keep some in your house safely in a ziplock bag (in case of water damage).  And take some to a safety deposit box or a safe location outside your house.  

Again,

Can anyone specifically elaborate on blockchain.info and any potential weak points?

because you are entrusting your asset to a party that is outside of yourself. you are outsourcing them instead of managing it yourself (by keeping a cold storage wallet).

Blockchain.info is a hybrid wallet (blockchain does not actually store the private keys), so it is much better than a typical online wallet. However, you are trusting them to not alter the Javascript that takes care of all the crypto. Theoretically, they (if compromised) could swap payout address right before the browser signs the transaction. There may be browser plugins that verify the browser code before it is executed.

Ultimately, you'll want to take the private key offline. See Armory for offline transactions.

Upload to an exchange, for example gox with yubikey.  

Again,

It is bad to store any coins online, on any website.

That was the answer to your question.  

The potential weak point is that websites can be hacked.  Sorry.  Thought that was obvious in my response.

The statement "Can someone elaborate on blockchain.info" is a vague question.  Elaborate in what way?  Do you need the basics on what it is?

Third party , can be hacked or "hacked" like this one:
https://bitcointalk.org/index.php?topic=248803.0

If you really want to hear more about it , go to the service discussion.

blockchain.info specifically:

They store an encrypted blob at their site which contains an encrypted version of your private keys.
They do not know your password that was used to encrypt the blob
Worst case someone hacks into their system and then takes all the encrypted blobs

Now they have your information, but it is encrypted.

They can now take their time and try to guess your password.  If they guess it your coins are gone.

But, as soon as your encrypted blob is taken you would be notified so you should be able to move all your coins off of those addresses on to new addresses before they guess your password.

So, use a very good password.

Does that answer your question?

Yes, and a very good way.  Just keep in mind the threats posed by metal detectors and ground penetrating radar.

Ok is there a dummies guide anywhere to transferring my bitcoins from blockchain.info into a paper wallet at bitaddress.org? And I mean a really intricate guide anyone with whatever little experience can follow? Such as; Step1. first click here,
Step2. then load up this,
Step3. then blah blah blah...

Pretty safe because your password is encrypted.  I think the only risk is a java hack at the precise moment you log-in. This is very unlikely.

That said, I would still not want to store large quantities of btc with any online wallet. One of life's great ironies is that the safest way to store this marvellous high tech digital currency is on a piece of paper ;-)

Here are a couple youtube videos.


I have not watched them, but they should give you a good idea.

https://www.youtube.com/watch?v=K0cGvUFBNEQ

https://www.youtube.com/watch?v=rYjH16zbf38

BTW you can create your paper wallets at blockchain.info directly.

Go to the "Receive Money" tab
Scroll down to the bottom
Click on "More Actions"
Select "New Cold Storage Address"
Enter your password
PRINT OUT THE PAPER WALLET
Click on "I printed it"

You will now see a new watch only cold storage address in your list of addresses!

Also, I never use the web interface to access blockchain.info - use the plug in, it is more secure.

There are two ways.

Method 1.

1. Download and save the bitaddress.org page as html
2. Disconnect your computer from the internet.
3. Reboot
4. Open the saved html file
5. Generate one or more paper wallets and print them out.
6. Reboot.
7. Go to blockchain
8. Transfer your btc to the public address on the paper wallet. This may require you to enter the public address manually or if you have a smart phone you can scan the paper wallet QR code.

Method 2.

For total security

1. Buy a USB key
2. Download  Ubuntu and save to key
3. Download bitaddress.org html and save to key
4. Set up your computer to boot off the USB key
5. Disconnect computer from internet.
6. Boot to Ubuntu off key
7. Run bitaddress.html in Ubuntu
8. Print wallet  (though nb not all printers work with Ubuntu - generic lasers tend to be better)
Then continue as per 6-8 above

 

Many on the forums use these, great design:
 
www.bitcoinpaperwallet.com

USB storage works too and is convenient, but USB keys fail and can easily be corrupted. 

Ok well I guess what I really want to know is how to get my bits onto a physical paper wallet and off blockchain.info. I just want the best easy secure method.

Thanks for the video links. Much clearer now.

Concise, germane

Excellent info thank you

You should know that insurance is a scam.  It should be obvious by the frequency with which insurance companies have to be bailed out by government intervention.  There is no real, guaranteed way to insure Bitcoins without controlling the network completely, which would destroy their value.

watch out for chase!

Paper wallet and perhaps a USB stick in a safe deposit box.  Import the addresses into Blockchain.info as Watch Only.

I think I get it.

However doesn't blockchain.info allow a second password for sending of funds?

Most major web sites (not just wallets) have several links of differing machines, each that can potentially have a vulnerability. When you connect to a web page, what you see on your browser is a web server. If it's a 'plain' web site, it talks on port 80, if it's HTTPS it talks on port 443. Just like your cable TV has one wire and hundreds of channels, networking can take place on one (or several) of 65535 ports (like channels).

The web server can be one machine, or it could be one of many in a rack. Ideally they are identical and have the same OS and updates on them. The web server(s) then typically talk to a backend database(s). This can also be one machine, or one of many in a rack. The web servers and the DB could be running different operating systems as well.

If it's a big place, they may have load balancers as well, to keep the traffic distributed between the various machines. They may have other machines to run mail services, and/or other machines to host FTP services. There can be other machines to hand out IP addresses (DHCP) if there is an office with some/many desktop PCs to be used.

They might not even be real PCs, many data centers and rent-a-server hosting places have 40-foot long cargo containers of servers, and the one you want to use may just be a virtual machine that is one of many. There can be dozens of different companies that are technically running on the same hardware.

This can be a lot of stuff to take care of, and most decent hosting centers handle the background OS and security updates. There is still the possibility of buggy code. The hardware and OS can be top-notch, but a careless developer may not parse inputs correctly, and the DB could be emptied with an SQL injection.

Or, somebody/anybody in the company could be lazy, and use their gmail/iTunes/whatever password as their admin password. A desktop PC that runs Windows can get a virus with a keylogger, even if the whole datacenter is 100% secure. If that password gets out, there's no need to break in, the attacker can just log in.

The point is, any modern large web site can be a lot of complex things to take care of, in addition to human error. It can provide a large amount of convenience to be able to do everything from your phone (for example). One of the great promises of bitcoin is the ability to be your own bank. Paper wallets or other cold storage are the ultimate in security, but they depend on you to keep it safe. 

If you leave a paper wallet in your desk drawer, it could be just like leaving your life's saving in a drawer. It's still vulnerable to plain old-fashioned burglary/fire/flood. Unlike fiat life savings, with bitcoin you can make copies!

Yes they do, last I checked.  Blockchain should be secure because they only store encrypted data on their servers, and they do the decryption on your computer using Javascript, I believe.  I had some doubt a month or two ago when a couple of people reported having their Blockchain wallets hacked.  But it could have been their PCs that were compromised rather than the site. 

Since paper wallet is prone to physical theft and loss, I tends to adopt this strategy:

1. Generate wallet.dat on an offline computer and set a pure random 20+ character password

2. Package the wallet.dat with strong encryption and another long password

3. Those passwords were written on two paper, stored at different geographical locations

4. Backup packaged wallet.dat in several locations, online storage or your webhotel

5. Move coins and change the wallet every 6 months

My bank account was closed by chase. not sure why. I have traded BTC with cash in chase, but very little activity.