Bitcoin Forum

I'm planning on getting one of these:

http://www.jazebra.com/images/product-shots/pill-fob/magnum-01-175x134.jpg

The ones offered on this website are supposedly survival-proof, airtight and also a tad expensive.
http://www.jazebra.com/pill-fob.html

You can get them from Deal Extreme for $1.5 (dunno about the quality) and I've also found this one on amazon (also airtight) for $5
http://www.amazon.com/Waterproof-Airtight-Pill-Holder-Keychain/dp/B0012NL9BI?SubscriptionId=AKIAI3W5KMBCWAZXJLTA&tag=surgeagur-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0012NL9BI

http://ecx.images-amazon.com/images/I/31eu9WVKFKL._AA300_.jpg

I could generate a key on an offline computer/secure computer and then keep the private key locked in there:

Pros:

- They are airtight and waterproof
- I suppose they would resist a fire if they're good quality
- The paper with the would not deteriorate
- They are small and can be carried around or hidden.
- You can seal them with some varnish and know when they were tampered with.

What do you think?

Nice idea, but not really fire resistant if you use paper wallet. The temperature inside the "bullet" can become of hundreds of °C in case of fire and paper burns at only 230°C and even the small amount of air inside can be enough to start a combustion

Anyway this is one of the most secure way to save a wallet I've seen.

Do you have the dealextreme link? What about a necklace with some good container?

Sure but a fireproof/waterproof media safe/container/chest is probably more secure.  Remember that while paper doesn't ignite until around 250C to 300C, it chars and blackens at only 150C.  A charred unreadable document still means lost funds.  While your metal container may survive the fire it will acts as an oven and destroy the information on the paper in any significant fire.

Even a normal fireproof safe will allow the temp to rise above 150C in a structure fire.  Depending on how long and severe the fire is you can lose some or all of the information on a paper documents.  Your best bet is a media safe.  Since digital media is destroyed at a much lower temp (~50C) these containers are designed to keep the internal temp lower than even "normal" fireproof safes.  You can get a fireproof/waterproof media container (with a nearly worthless lock) for $30 to $50.

If you are ultra pranoid get a fireproof/waterproof media container and then put that inside a TL-15 burglary safe. :)
  

etch your key onto a small piece of metal and store the metal in a heat proof box.

I'll take a look at the media safes.


Do you know how I could etch the key without owning laser etching equiment or similar tools?

For my cold storage, I've used some black granite tile with one of these:

http://www.dremel.com/en-us/tools/Pages/ToolDetail.aspx?pid=290-01

There are few materials more enduring than stone.  It won't fade, rust, decay, burn, or dissolve.  That engraving tool is cheap and easy to use.  It took only a few minutes of practice to get a feel for it, and I can engrave a private key in less than a half hour.  Polished granite tile is available at just about any flooring or home improvement store.

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&langId=-1&productId=2113244

P.S.  Laser printer toner makes great masking material, but it may take you a couple of tries to get the bonding step right.

Use your noodle? A strip of ally or copper should do fine ....

http://ecx.images-amazon.com/images/I/51fX1xMaHML._SY300_.jpg

Google "Letter and Number Stamp Punch"

Edit: Run Linux LiveCD on offline computer, botg.sh https://bitcointalk.org/index.php?topic=23081.0 (https://bitcointalk.org/index.php?topic=23081.0) (on a clean USB stick), metal strip, number-letter punch and you're done. Probably as simple, and cheap as you can get, yet effective.

I thought of the stamp set but every set I found is just the capital letters.  Maybe you could do the letters upside down to signify lower case.

Definitely wouldn't recommend a pill capsule with a scroll of paper inside.


https://bitcointalk.org/index.php?topic=134229.msg1429516#msg1429516

You could just do the SHA256 hash of a set of random capital letters/numbers that you want, and use the result as your private key.

Precede the random characters with "SHA256" so you don't forget that's how to use them.  :P

Just make sure its fire proof!

Why not store your private key in an ATP microSD card and store it in your container?

http://www.atpinc.com/p2-4a.php?sn=00000391

Electronic storage is not intended for long term: electromagnetic fields can wipe out your data, and due to memory cells structure the data can fade if not refreshed in 4-5 years

I have to say, that's just brilliant.

Or you can easily scratch copper with any hard sharp object.

Or you could use a piece of wire and make notches every so many mm apart indicating 1-16 hex. That would take max. 1m, but more likely a half meter.
(I'd make mine the seed for an Electrum wallet, and that's only 32 hex digits, mine took <12cm - though you could just scratch the words on copper.) I like ways that are free and immediate, and I have copper wire anyway. (You can actually slip the plastic coating back on and it's "invisible" 8))

Etch stainless steel or similar metal with chemicals:

http://www.wikihow.com/Acid-Etch-Steel

http://steampunkworkshop.com/electroetch.shtml

http://www.makersgallery.com/goss/etch.html

You could make the print rather small and clear and then store this in plain sight? In fact, you may be able to make it so small, it could only be visible with a magnifying glass.

Lower case alphabet sets are not hard to find ... not sure how hard you looked.

http://www.pjtool.com/metalalphabetlettersstampingset-1.aspx (http://www.pjtool.com/metalalphabetlettersstampingset-1.aspx)

The biggest flaw is the possibility for human error transcribing the private key ... whilst thinking of the millions that could go into your address your hands might start sweating, trembling and the hammer slips, letter's all askew and you've skinned your knuckles ...  ;D

Edit: you'll want at least 63 piece set or the deluxe 72 ... upper lower and numbers, punctuations also if you like http://www.ebay.com/itm/72p-Mazbot-2-5mm-Steel-Letter-Die-Stamp-Metal-Punch-Set-/270669621438#vi-content (http://www.ebay.com/itm/72p-Mazbot-2-5mm-Steel-Letter-Die-Stamp-Metal-Punch-Set-/270669621438#vi-content)  ... a nicely weighted ball-pen hammer is the best for stamping, could be useful against intruders looking for your private key hidey hole also.

Cut a wound in your arm down to the bone and make notches on the bone instead of copper wire.
When the wound heals, these notches might be visible on an x-ray machine.
This might be a good option for an apocalypse. You would be able to fashion your own x-ray machine using parts from old microwaves.

What a nonsense!

Oh, wait, in fact you really might build bind of an x-ray from a microwave magneton!
Go ahead!
Post pics, you can blur out the actual code in your bone too ;-)

Ente

I just use Blockchain... Hopefully its safe enough

Let's get even more extreme...

Store it in a strand of DNA?  Then make the DNA recreate itself (I have no idea how this stuff works), and store the resulting biomatter in a container kept frozen.  Whenever you need the data, just pick a small portion of the matter out and scan the DNA.

???

This seems unlikely.

As I understand it, microwaves have a wavelength of between 1 millimeter and 1 meter (longer wavelength than visible light). x-rays have a wavelength between 10 nanometers and 0.01 nanometers (shorter than visible light).  Microwaves mostly tend to be absorbed by the body resulting in a build up of heat.  X-rays mostly tend to pass through a body allowing an image to be captured on a film placed on the opposite side (and not building up much heat). I doubt you could fashion an x-ray machine from a microwave anymore than you could cook your food with an x-ray machine.

More energy needed for the higher wavelength of x-rays. You can make x-rays in a similar fashion to how a microwave works. ie by smashing electrons against a metal target.
Just need to up the potential used in your accelerator.
Do this by altering the coil windings or using two transformers etc. Just make sure your rectifier can handle the voltage increase.

A cathode ray TV might make more sense actually since the voltages are already alot higher.

Think a microwave is only about 2000 volts. A TV might be like 20,000 v I guess. In fact TV's have leaded glass in their screen for this reason. It can be dodgy to turn up the voltage too high when adjusting things inside due to x-ray dangers.

Hiding your bitcoin internally would keep it from the man. A laser could be used to burn the code into your retina!

why not store the paper wallet in the same place you store your car title.. house deed etc?

Dude.  That is NOT how a magnetron works.  Magnetrons are oscillators, not accelerators.  And the frequency is controlled by the geometry of the resonant cavities, not the voltage.  If you increase the gate voltage, you might kill yourself, but you won't get x-rays.

Shut up before someone gets hurt.

nobody would seriously try this. :P It's highly dangerous not to mention the risk of infection.

The part about cathode ray tubes was correct.

If you ever get your hands on a schematic for a CRT display you'll find marked components for X-ray protection. They keep the voltage in the flyback transformer from exceeding a value which could produce X-rays.

Well that escalated quickly.

https://i.imgur.com/BTlJy.jpg

is it though??

That depends on your needs and on how you use it.

+1

Engrave a piece of metal If you are planning to store a paper wallet for a long time and in the outdoors, you should just engrave a piece of metal. You can do it at the mall (Fast Fix) for a couple bucks. It will cost more than the little canister, but it will do a better job than writing it on a piece of paper. You could even put your engraved metal in the canister.

Simple as that. I'm not sure you need an x-ray machine.

I would keep it in a cheap fire proof safe

The smartest thing to do is to engrave the private key on the lens inn your eye. That way you can always see it. Since Im into AltCoins I have a huge list of priv keys so I had to dedicated my left eyeye for this. But its pretty safe. Will never in my life use a retina scanner though. Also since priv key is so dangerous if other see it, nowadays I only use the public key.

Edit: on a more serious note I guess the priv key isis best stored, engraved in a durable material duch as metal or stone. If metal starts to corrode, just make a new one. Dont engrave inn goöd or silver though because most people will see another type of value in those.

why not select one aribtray transaction from the blockchain .. maybe the first you have ever done using your first BTCs ... selected the last 60 letters of the transaction id .. run  sha256 and/or other hash over it an use the result as privkey .. .. that way you can always get you privkey aslong as the block chain exists. .. if it seases to exist, you coins are gone too :-)

I like that cointainer...... wait.. I am going to market those and call them that coin-tainers! ... Okay, I said it first, if you wish to use the name, you can use it for free as long as you mention me. But you can also tip me a royalty. (or you could care less and just use it anyway, that would be sad; unless you pretend you never heard of it from here.)

Coin-tainer by Dabs. Stainless Steel Cold Storage.

Why don't you just write it on papyrus paper using carbon soot from an olive oil lamp as ink. Then put it in a clay jar and store it in a cave. I hear that will last for a couple of thousand years.

I will be offering Bitcoin Private keys laser engraved in diamonds pretty soon. It's a little bit more complicated then originally expected so there are a few things to work out still, but my service is coming. :-)

Sounds like a James Bond movie "Diamonds Are Forever Your Bitcoins".

Instead of the "forever" echo in the theme song, it would be "diamonds are forever... (your bitcoins, your bitcoins)". LOL

Short of killing the engraver (or data entry person) ... how have you got around the security leak of sharing private keys with the engraver?

I'll make a guess. Completely computerized, disconnected from the internet, automatic engraving machine. For absolute security, the client will go to the location to pick up his or her choice of diamond (or bring your own), and engrave the private key on the spot, with only the client knowing the private key.

The engraving machine then engraves the key, much like a printer prints on paper.

Then it clears it's memory and resets, and you can verify that the machine no longer has your private key. Or reasonably sure it is securely deleted.

It seems that house fires are unlikely to get that hot usually but something to bear in mind.

Are you supposed to put that in your butt?

I used two methods.
The first I put one copy of my wallet in my gun safe.
It's fireproof to a huge temp.  I printed it and laminated it.  I also put in on a metal plate in the safe.
The 2nd is backed up to 4 flash drives one in a safe deposit at the bank one is hidden in the house.  Another in a family members safe and the last at my best friends house in his safe.  Each USB drive is encrypted and passcoded.
I went nuts I just don't want to lose access the the tiny amount I have.

Make a paper wallet using the link in my signature. If you are paranoid print your paper wallets using "hiren's boot CD" disconnected from the internet with the print spooler turned off.  Buy a cheap laminator and the credit card sized laminating pads from wally-fart. Print your wallet and private key and follow the directions. The private key cannot be exposed unless the lamination is cut open and the cold storage is now fairly weatherproof and you can make multiple copies of a single wallet for a safe deposit box or whatever.

It would be fairly difficult to break open the lamination without anyone noticing, or adding personal identification or watermarks underneath, so it might be useful for selling... can only be returned if lamination is intact, etc. I'd use a UV marker to the underside of the lamination before laminating then you can detect of the lamination is your original lamination.. all sorts of ideas along those lines.

I love laminating things. What self respecting male doesn't love playing with fire, or heat and melting things? ;)

Laminating is fun.
For quite a while years ago I laminated tons of stuff just to do it like a dork.  My girlfriend at the time (now Wife) thought I was goofy.  Joke was on her when we had moved and a couple boxes got wet.  She was so happy I had laminated a couple of her certifications.  She did not lose them.

nice. My newest thing is storing all my account passwords on "lastpass" .. all of them are now random gibberish passwords generated from password generators... the master password to lastpass is a random password I have laminated into a QR code stored in my physical wallet and safe deposit box. The password to the main google account associated with all my important accounts including lastpass has it's own random  password that is also laminated as a QR code.. this password is not stored on lastpass. Both are protected by google 2 factor authentication. As secure as I can make it and no longer have to remember passwords. :) I have an "MS-1690" 2D USB barcode scanner I bought on ebay recently to scan these barcodes if I'm not using a phone (which I don't and have the mobile bypass feature turned off)

"I just scored 97.4% on the LastPass Security Challenge ranking 1678th overall. It securely analyzes the strength of your passwords, alerts you if you have any duplicate or weak passwords, and tells you how to make them more secure."

https://i.imgur.com/WUtFKdU.png

I also made and laminated a series of barcodes for work since we use barcode scanners as part of the job and have to change passwords and remember usernames and sometimes relogin to buggy java software that freezes every hour or two, the barcodes come in handy. :)

This brings up another little thing I enjoy doing.. making complex 2D barcodes of various types and with various texts.. I don't know why barcodes fascinate me... I can't imagine before the days of bar codes and self checkout having to wait behind a line of old farmer joes as they manually type in the price of everything by hand.. I'd go crazy!

Now that is some work that comes in handy.
Even barcodes that is cool.
I have not gotten that creative yet but you have given me ideas.  ;D

Armory paper wallet packup, with a 2-of-3 recovery option, or 3-of-5 or whatever.

As long as you're the only one who knows the location of ALL 2 (or 3) pieces needed to restore, it doesn't matter if one of the pieces burns.

very sweet.

Just thought I'd introduce you to new little stainless steel bitcoin cold storage wallets that are laser etched and fireproof, almost indestructible. We think the pricing is on point and hopefully you love them as much as I do! Feedback (and orders) is appreciated.
https://ColdCoins.co

Someone recommended the following method to me and it is really an outstanding way to secure your wallet AND add redundancy. My friend compared it to the horcruxes in Harry Potter.
-First, You'll want to boot into linux (you can do this on a flash drive, if you don't know how to do this, comment here and I will be happy to help you out) and do not connect to the internet at all.
-Second, you should already have the java applets www.bitaddress.org and www.passguardian.com saved on a flash drive. You'll need to access these files (they'll open in the internet browser.
-Third, the bitaddress applet will generate a public key (bitcoin address) and a private key (the password you need to extract your bitcoins). Save the public key somewhere (perhaps the flash drive) so that you can send BTC into that BTC address.
-Fourth, copy the private key and open the passguardian applet. You will want to select split a secret. Here you will paste the private key into the box that says "secret to share".
-Next, you select the number of shares (i usually pick 7) and threshold (i usually pick 4). This means that you will receive 7 different passcodes and in order to recover your "secret" you need to have any 4 of the 7 shares.
So passing it out to 7 shares to 7 people that you could trust, parents get one, sister, friends, etc. But shit happens. People lose stuff, houses burn down, people get robbed. If you set it up this way, you only have to rely on 4 out of 7 people to actually keep that share.

Copy and paste from Reddit? Also, whenever I try to get to ColdCoins in doesn't load the page:(

Guys, what do you think about buying an android phone with the sole purpose of keeping bitcoins? would that be safe?
One could encrypt the backup folder onto a USB stick or your computer, and keep the phone in cold storage - never mind having a sim card or anything.

would the bitcoin app for Android phones be secure to do this? you could also set a key to unlock your phone.

Android is bad news for malware. Cold storage should be just that: totally offline.
I've experimented with the punches. I modified a python script on mini private keys (google it for the original) to use only caps and numbers. You still get 145 bits of entropy, which is stronger than the original Casascius coins and should do the job fine.
I'd been playing with the idea of coin rings for my wife's Christmas present, so I banged an all-caps mini private key into a 50 eurocent coin (Nordic gold, thick, malleable, hypoallergenic...) and turned it into a ring using a mandrel and hammer. Nice, chunky, manly ring with the code faintly visible on the inside (especially after being given the fire treatment like in Lord of the Rings). The one problem is that anyone who knew that's what it was could steal your coins, but 1) that's true of any form of cold storage, 2) they'd have to know about it, and 3) they'd have to get it off my finger first, and then get to a computer faster than me (I memorised the code for good measure).

I'd love to make these for other people, but haven't figured out a straightforward way of doing it without trust. Unlike Casascius, I'm not prepared to give out my home address in the interests of transparency.

If I ever own enough btc to make it worthwhile, I'll probably experiment with saline etching of stainless steel and bang some more keys into aluminium blocks, like little metal bricks. Reckon you could hide them in stud walls, under floor boards, or wherever - varnish or oil them to make sure there would be no corrosion first if they came into contact with damp.

Oops, missed the bit about not having a sim card!
Still not sure I'd trust something like a phone. But writing them to the sim card itself might be a cool option.

Yeah, what one would have to know is how the private key is protected from google apps - if google apps be the problem.

If I can find the courage/reason to trust basic default google apps on my phone, then I think it would be a pretty cool solution to cold storage. I could connect it to wifi whenever needed, easy to use, and keep it in cold storage for the rest of the time. most android phones have a pin option to unlock the phone also.

I think the android phone will be the model for hand held bitcoin wallets to come.

Everyone knows Mt Gox is the perfect Bitcoin cold storage solution.

LOL
Now that one is killing me with laughter.
Unfortunately you are right.   :-\

*cough* http://www.bitcoinclassifieds.net/ad/5693_Tekton_532_in_letter__number_stamp_set/

Yes, great way to make sure your coins are out of reach of anyone...

sounds like the government can implement its human chip via cold storage, if you believe in conspiracy theories.. heh.

Whats more secure than embedding ya wallet in yourself.

Take worth a million dollars to a whole new level. :P

I have my casascius coins hidden in my freezer!

Until you need them and have to pull them out your nose like Arnie in Total Recall  ;D

Best way. Write down your private key and put it in this. It is not fire and water resistant. Bury it somewhere and there. Done. Safe. 

So... you are going to make an end of the world proof cold storage, which will then allow you to collect your Bitcoins from cold storage and exchange them... uh... yeah.

Makes perfect sense, because, you know, physical mediums are exactly what Bitcoins are all about.

I get that you want a cold storage to keep your coins safe, and I get that this is best practice (I support it too), but leather punches and etching the codes into metal and stone?

Have you considered a tattoo? Likely less expensive than the other options. You could even get it tattooed backwards on your forehead so that you could read it in a mirror, but no one else would know. Or you could tattoo it in between your ass cheeks. Surely no one would look there - of course, how you would read it when the hair grows back might be an issue.

Oh, I know! Maybe you could paint them on a canvas, and then paint another painting over top of it. Then they could make a movie about it. Or, perhaps you could just get some of that glow in the dark paint - or even some black light paint - unless, you know, you have Goth or Goth Lite (Emo) friends.

Just saying man. What you want to do with preserving the information and protecting it is a bit extreme - especially considering that all I need to steal your money in America is a signed check. Did you know that it is that easy in the US to steal money? Yep - it sure is - because account security is largely based on the ID of the person receiving the money, and the ability of banks to prosecute them if they commit fraud. It doesn't always work though.

Of course, none of these methods will protect it from the pirate killing ninjas the NSA sends out to read people's mail and see what kind of toilet paper they have used.

So - deep breath, and consider what it is you're really trying to accomplish here before you start stockpiling cans with rolled metal lids so you can open them on rocks when the world ends (all while secretly having your Bitcoin info etched in the bottom of the rock).

Oh yeah - no offense either. I have a tin hat too.  :D

Are they the chocolate kind?

You could do a Gox by putting a number on your watch only wallet screen which shows a balance but never actaully check the cold address to update it.

A riddle:
Why is Charlie Shrem called "four-finger Charlie" by his friends?
All right, that's an easy one ;-)

Ente

Letter and Number Stamp Punch  will be the best thing to do  ;) :) :) :)

Our advancement in technology left a lot of people in rather uncomfortable position when they can't store wealth in more traditional way. Those containers are trying to mimic solutions we used to have for gold and coins for rather long time.  I am a bit surprised we haven't go further with solutions. More advanced, less reliable on battery's, low temperature and physical damage. some of those odds and ends are even a bit nostalgic, to hold our virtual belongings on necklace or key chain. 

I'm afraid we need more advanced solutions. Storing meta-currency is bit different and we should't think about like a normal data. Maybe plastic version of paper print.

Have it engraved under a ring on your finger.

Get a trusted jewleller to do it and never give him or let him copy the key / phrase and make sure you are present when they do it.

Simple, always on your person and if on a wedding ring, never comes off.

I got a better one:
Write half of the private key on your ring, and half of if on another ring that a family member keeps.
A thief would need both of the rings to steal your coins.

And you should of course have "backups" of the rings in case of loss: keep the backups at two different bank vaults.

You should also go to two different jewelers to engrave half of the private key, none of them have the full key so they can't take your coins, unless they know each other and collude to steal your coins.

Sorry if the question has been answered elsewhere. Is it correct to assume that the creator of these coins may have a copy of the secret key? I am not saying that he has a copy or that he intends to use it. I am talking about technical possibility.

A technical possibility? Absolutely.

Casascius has about as good of a reputation in the bitcoin community as anyone can have.  He has stated that he absolutely does not maintain records of the private keys.  You have to decide for yourself if you trust that claim or not.

Ha.... I don't keep much on my ring.
Wonder if Shrem was wearing it when he was arrested, and if any of the cops was smart enough to copy the private key off it.
I'd like a way of making them that minimises trust. Any ideas?

Trust, security against what?
There are many risks here. Robbery for the ring, robbery for the coins, the goldsmith steals your stuff, you want to quickly access your funds, inheritage, the list goes on and on.. :-)

So, generally speaking, we don't need one solution, but a whole system. And this one will be different depending on use case.

Ente

I've made paper wallets from there and it seems like one of the 'safest' methods there is.

The code is open source so you can check it: https://github.com/cantonbecker/bitcoinpaperwallet

There are also PGP signatures so you can check your downloaded file is uncorrupted.

Best method is to download the source and run it on an offline comp to generate and print wallets and then format that comp.

I've also imported from these wallets into blockchain.info without issues.

Hope that helps.

We should ask Mark Karpeles what kind of cold storage he used, so we don't make the same mistake :D

I heard he kept all the btc on a waterproof flashdrive at the bottom of an iced coffee.

True, though I mean specifically my case, where I make rings/jewellery etc for other people. I don't like the idea of them sending me encrypted keys, since they will only be as strong as the password they choose (and remember).

He forgot about it and threw away the container in frustration.  Now the flashdrive is in a junkyard in the landfill in the UK sharing tea and crupmets with the 7K BTC hard drive.

It looks like his basic problem was not understanding the difference between cold and hot storage. But I don't know why that surprises me...

For people sending some one else their keys to engrave or similar:

- Trust the creator, like Mike/Casascius
- Encrypt the key, there's a BIP for that (and remember the password)
- Split the key between several rings/engravers (shamirs SSSS, or half a key for each)

In all three cases the user has to trust someone: the engraver, himself or the engravers.
I, personally, don't like to need a password for my cold storage. Cold storage is, for me, the absolute last resort when everything else went up in flames (literally, computer burned away, or I am not able to redeem any coins any more).

Ente

Thanks. That sounds about right. I don't like the idea of encrypting cold storage keys either, though I think generally obfuscating them a bit is a good idea. Neither do I like the idea of being trusted: even if I am trustworthy, if the coins get stolen somehow then I'll naturally fall under suspicion.
Myself, I'd plan on several cold/hot wallet variations to spread the risk.
I think this is actually one of the barriers to proper bitcoin adoption at the moment. Until we have more storage and insurance services, most people won't like the idea of "keeping" their coins in the form of a long number somewhere. Most likely that's only really going to appeal to hardened bitcoiners, who understand the protocol well enough to do it properly.

The problem with traditional 'physical' cold storage solutions is yes they may be offline, but they are not immune to natural disaster, theft or loss. I found https://www.cryowallet.com which kinda gives you the best of both worlds. You wallet can be 'evoked' when you login in. Nothing executes on their servers, everything runs locally in your browser memory and when you logout there's no trace left on your machine. Not even they have access to your provate keys/coins. So they cant be hacked, you cant be hacked and in the event of a disaster of some sort, you can evoke your wallet from any device.

Metal Bitcoin firesafes (https://bitcointalk.org/index.php?topic=349465.0) seem to be a good idea. Aluminium and stainless steel ones are available. One poster suggested that a Titanium one would be even better.

I recall seeing a thread somewhere also offering wooden versions.

That's a good idea as long is the safe is small and cleverly hidden. 

Having a safe in your closet or behind a picture frame is like putting up a neon sign that says, "here are my valuables!"

No real need. How easy is it to hide a private key somewhere? A safe just tells people what's in it is valuable. Usually I'd despise security by obscurity; in this case it makes sense.

Everything is explained here http://ecoinocity.com/make-or-buy-metal-offline-cold-storage-hardware-bitcoin-wallet/ on how to make or buy a metal cold storage bitcoin wallet. It will withstand a fire but will be even safer when stored in a safe deposit box in your local bank. Also make a copy and keep it in a fire proof safe in your home. This is hacker proof.
Also once the wallet is created there are particular procedures you need to follow (see the post url listed above). For example you must empty the whole balance and do not reuse the wallet.
http://ecoinocity.com/wp-content/uploads/2014/02/metalbitcoinwalletbest2-300x225.jpg

Make sure no one is "shoulder surfing" you when you make your cold wallet. Or make sure there are no webcams hidden in your room. Enemy of the State or Anti-Trust or stuff like that. Don't forget to wear your tin foil hat.

Speaking of which, make sure your monitor is properly shielded to prevent signals flying to the white van outside, where they can read everything that you see.

You could argue for the case of using casino grade dice to generate private keys. Alternatively there are hexadecimal dice. Read about diceware, apply the same thought process to private key generation.

Personally, just use an old computer or laptop in a secure room or basement of your location.

Check out the Bitcoin Firesafe (http://bitcoinfiresafe.com/).  It's a chunk of Aluminum or Stainless Steel with a QR Code of your BIP-38 encrypted key engraved into it...  so the manufacturer can't have access to your funds, and the instrument is 2-factor secure... i.e. if it is ever stolen from you, it is still useless without the password.  There are discounts for duplicates too.

Stainless:
https://i.imgur.com/Va97LQtl.jpg (http://bitcoinfiresafe.com/products/4-classic-safe-1783)

Aluminum:
https://i.imgur.com/W3VkbTN.jpg?1 (http://bitcoinfiresafe.com/products/3-classic-safe-934)

Disclosure: I invented and sell this.

Steel? Engraved? BIP0038? Finally a commercial solution which does it right!
Good work!

Ente

If you can remember the password used to encrypt the private key, who not just make the private key the SHA256 hash of the password? Then there's no need to store anything.

Awesome!

True.
With the BIP0038 approach, you have both more risk (you can lose the QR code) and more security ("2 factor").

Also, the passphrase for a direct SHA256 output needs to be *very* secure, as there are already many automated brainwallet harvester out there. I don't want to imagine how much hashingpower they are throwing at this. Your brainwallet is attacked since the instant it exists.

On the other hand, BIP0038 passwords are much more difficult to calculate or to brute-force. Also, attacking your individual QR wallet can only start when someone learned the QR code. Which, normally, you will notice, with enough time to sweep it.

For this, I would recommend to cover the QR code. It's no good idea to let everyone know "hey, I spent a lot of time and money on securing my bitcoins, and here they are!". And with the QR code visible on your keychain, it's too easy for others to scan it.

Glue a picture of your significant other on it:
- Noone will steal it
- You can honestly say "that's my most precious thing I have!" :-)

Ente

Acknowledged. My real thought here is that many of these storage options seemed designed to outlast their owners. As such they should perhaps be self-contained and not rely on a password stored within a fragile skull.

(Actually, some of them seem designed to outlast the internet.)

Really? If I transfer 100 BTC to a new brainwallet, how does anyone know that the address is a brainwallet that is worth attacking? Are people attacking every address that has significant funds?

Yes. And the attacks are very sophisticated and powerful.

Looks safe, u should also have another backup

I like to just keep offline wallet.dat files on a usb stick and a cd-r.

Type? Maybe if you're one of those fancy big-city fellers.

http://1.bp.blogspot.com/-3TkRqDIgCN8/UFI_jxiOGrI/AAAAAAAABew/RH8i0dh-awU/s320/cash+register.jpg

I just have a paper wallet which is kept in a fire proof safe I think that's enough to be honest unless they manage to steal the safe and happen to know how to use a Bitcoin wallet.

Really? If I transfer 100 BTC to a new brainwallet, how does anyone know that the address is a brainwallet that is worth attacking? Are people attacking every address that has significant funds?
[/quote]It isn't that people are targeting specific bitcoin addresses but are rather searching the public addresses of many possible brain wallets to check for bitcoin and if there is any they will send the bitcoin to an address that they control.

With a brain wallet there is little risk that you are targeted directly, but rather have the risk that an attacker will guess your password and steal your coins.

If I did own a lot of bitcoins I would just use xapo.com. I'm not trying to advertise or anything but they are fully insured, so it is simply not possible to lose your bitcoins. Also I could easily lose the private key, paper wallet, or wherever I stored it. My house could burn down, someone could steal it, too much risk.

If you don't have possession of the private keys then all you hold is a promissory note. Here is a tool I've created for myself and my clients:

http://coinkee.com

You can create something like this for yourself. Download the bitaddress.org files from the source and save them directly to a new flash drive and create a ubuntu LiveCD to boot up with before accessing the USB/bitaddress files. Don't connect to the internet and print your paper wallets using a printer cable to your printer (not wifi). Use the LiveCD and the USB for creating wallets only and for no other purpose.

Create BIP38 encrypted paper wallets with multiple copies (backups) and store them in geographically diverse locations (house, office, relative's home). Do this and you should be good to go. You can "cash" the paper wallets using wallets like Mycelium or Blockchain.info.

EDIT: You can create a custom Ubuntu LiveCD/USB with bitaddress.org pre-installed so you don't have to have a separate flash drive to hold the bitaddress files.

i just use an old usb flashdisk and little dirty  :P
who wants to pick it up

Whether they know how to use a Bitcoin wallet is not important.  If they steal the safe, your bitcoins are gone.  That's the important bit.

I think it's easier and perfectly safe to hide an Electrum wallet seed, say in two parts, in pictures or documents, for example.  That way you can copy it to several places, including online storage or email.  No one will know they contain the seed, unless you do something daft like tag them with "Electrum" or "wallet".

Just make sure you have more backups than that as USB sticks have known to stop working over a significant period of time.

I saw an interesting guide on mining bitcoins that also covers the security elements and cold storage. There is a special USB that is being developed that hold's your private signature and cannot be hacked. If you are also new to mining it is also worth a read, Mining Digital Currencies Ultimate Guide (http://"https://www.ddmarkets.com/mining-digital-currencies-the-ultimate-guide/")

To store my btc savings I used the classic ubuntu live cd method.
While disconnected from internet you have to generate a wallet.dat and put it on various usb supports.
Then save your public addresses on a text file and send your btc on the cold wallet,
finally check from a block explorer if the transaction was successful.

In the link I posted it covers TREZOR, it will be released soon, I think all preorders are booked.

Oh I guess a few days ago there's been a post on reddit (I guess) about some water/fire(?)-proof paper that's supposed to be perfect for paperwallets!

Yes, I saw that too.
If you rely on the paper being robust against water or mold or other things, you might be doing it wrong.
Have several copies. At some different physical locations. Don't use the same medium for all of them, and have at least one "plain" paper/metal/qr one.

While at it, solve the "what happens when I'm not able to retrieve them because of injury or memory loss or worse" problem too. :-)

Ente

Exactly. Also consider splitting the key into multiple pieces (n-pieces) where you need at least a certain number (e.g. 1/2 * n) of those pieces to retrieve the key.

I think it needs a bit more bling-bling. To be honest, I carry around my dollars in an adequately fat purse. Why would I keep my Bitcoin in a sub-standard keychain?

I recently saw a suggestion to use sparkle/glitter nail polish to seal something. Each dab drys unique. You can tell if it has been tampered with or even take a picture to see if it is the original dab.

Awesome! That way we even had more bling-bling in the Bitcoin world! I like that idea A LOT!

#3 paper wallet stored in safety deposit box
#2 crypto cards (http://cryptocards.co/)
#1 Brain Wallet*

*But not if you're a moron

#2 is probably a bad idea, as it would likely mean that you are trusting your private keys to a 3rd party.

#3 is most likely bad because the human brain is very bad at being random and will likely pick something that can be guessed by the many botnets that are checking possible brain wallet combinations.

I beg to differ regarding Brain Wallets. Brain Wallets can be the most powerful wallets if you take care to use a protocol like Diceware to generate your passphrase and then use the simple method to memorize it as described in the link below.

The advantage of brain wallets is the fact that you can lose everything (backups included) and you can still regenerate your wallets. If you are worried about forgetting your passphrase, split the passphrase into multiple pieces stored in multiple different locations and then add redundancy if so desired.

Brain Wallets Aren't Just For Spies - How to store bitcoins in your brain
http://digitalcurrencyinstitute.org/brain-wallets-arent-just-for-spies-how-to-store-bitcons-in-your-brain/

How To Create Super-secure and Easily Memorable Passphrases
http://digitalcurrencyinstitute.org/how-to-create-super-secure-and-easily-memorable-passphrases/

Of course, my favorite tool to create these is my CoinKee™ http://coinkee.com  :)

BTW, crypto cards are fine if you use a strong passphrase to encrypt your private key via BIP38 before sending it to them for manufacture.

Just insure it and put it in the local bank safe box...  ;D

The service https://BitArmored.com is extremely high-security cold storage with a Live/Hot Wallet for instant transfers and option to store large amounts offline in cold storage.  You can even request an encrypted flash drive containing an electrum wallet which is what we use for each client's funds.

disclaimer: I own the website

I've heard good things about bitplastic, which is also owned by you correct? I would trust it if I had a lot of bitcoin, but I dont...

I'm building what I think will be if not one of the best cold-storage devices certainly the most attractive. :-)

www.aeternum.in (http://www.aeternum.in)

http://cdn.shopify.com/s/files/1/0505/3357/t/2/assets/slideshow_2.jpg?314

I think best method 3d printed wallet. Ultimaker 2 can make really good 3d printed QR code.

Wow these look cool.
How close are you and do you need funding?

Sure looks funky!
After searching through your site way too long, I found the description page.
That page doesn't really explain what this *is*!

What is it? What material is outside? What's inside? Seed, key, wallet? Encrypted? BIP0038?
In case that stuff is written on that page, sorry, I only skipped through it after reading half of it - it's too much text.

I don't mean to offend you, it's meant as constructive criticism!

Ente

Glad to know. I guess the people who uses the usb which was installed with linux system where their bitcoins were stored aren't also safe.

How do you  store them in Airtight Pill Fob by the way? are you going to write down your btc address and password in a paper store in that Pill Fob ?

I'll make a better site in september to better explain it. I was actually thinking to do a little video to help explain. Basically it's an NFC device sealed inside a device that can't be counterfeited nor broken open and resealed. It's one time use only and serves as like a secure password container where you don't need to trust me the manufacturer to safely use.

I've bee showing a lot of people in person and testing different ways of explaining how it works. Once I hit on the simplest way to explain it I'll let you know! But generally september I'll do better at explaining that. :-)

I am using #3, as I believe that paper wallets is the most safe option. Right now no computer program is capable of cracking a 22-character long pass phrase (that doesn't mean that in future it might still be so).

I think I can see what you are doing ... it's cool! Keep the rabbit in your hat, for now.

Go ahead and do a web search on bitarmored or check http://antilyze.com

Moriarty steals bitcoin = FACT

I like this a lot, I would be very interested in buying one!! I think il get one of these and dig a 2 ft hole in the garden place in in the hole and put a rock over directly where it is just in-case of a house fire or robbery or anything.

That sounds cool!
Well, as long as that stuff is long-term reliable.
Remember how they told us "CDs last 100 years" or the like? I had problems reading in my CD-Rs after less than 10 years..
Flash cells are worse. Now I don't know a lot about NFC chips, but would always feel safer having at least one optically-readable backup. And that means at least a QR-code, and preferrably something with letters and numbers.

Actually I had that idea as a child: some secret message enclosed into a glass tube, where you couldn't read it without breaking it open first! So, yay for nice flashy coldwallet!

Ente

Those look really cool.   Kind of how I would imagine pills in heaven...lol.   I have been thinking about getting one of these.   I like to spread things out in multiple places so it isn't all in one spot.   Andreas was talking about how he carries around a FOB with an operating system and wallet on it...

So basically this is a tampon that is inserted in the wifes vag?

Only if you trust your wife. Otherwise, hide it inside your own body.

when i earn my first few bitcoins i will try these

In light of this:

http://www.wired.com/2014/07/usb-security/

CoinKee is transitioning to CoinPro (no USB - LiveCD only):

http://coinpro.me

This is a good move considering the recent USB firmware hack that came to light. I can't find the link at the moment, but suffice it to say I didn't know USB firmware could do that shit.  I hate discs altogether, but it seems that lo-tek old school is proving more and more secure every day.

best Bitcoin cold storage is https://BitArmored.com

LOL -- see http://antilyze.com and http://www.badbitcoin.org/thebadlist/index.htm

I currently use an always offline Raspberry Pi with Electrum.  Signing transactions is easy enough and hiding the 12 word mnemonic code in random files and emails means I can rebuild the wallet at any time, anywhere in the world, should I need to.

Mycelium is great for spending from cold storage wallets too (change is returned to the same address).

I have now been using trezor as cold storage.   I like how it is almost like a hybrid wallet, where you don't have to sweep the entire thing when you want to spend.

The one downside is that you have to rely on their API (I think).   The backend of the website was down the other night, so none of us had access to our coins in the meantime (unless you wanted to use the recovery seed on a different wallet)

Its looks like vibrators.

I would not trust trezor because their hardware is very new and untested. They do have "open source" software, however you do not have any real way of verifying that the software on your trezor is the software on github. You also have a huge amount of risk regarding the shippment as you do not have any real way to verify that the shipment was actually sent by trezor and was not intercepted

Someone said that a floppy disk is the best bitcoin cold storage.

We seem to have quite a few topics created about "cold storage" lately - anyway for anyone interested in 100% "air-gapped" security using an Live OS (created using SUSE Studio) there is this: https://susestudio.com/a/kp8B3G/ciyam-safe (it combines an offline bitcoind with GPG, scrypt and does all comms between online and offline computers via QR codes).

I personally do not trust trezor. You should have 100% access to your private key at any time. If their website goes down then you need to have a way to recover the private keys

Well, use your backup! :-P
It's standard-conforming, following the BIP0038 scheme.
Either put it into another Trezor, or in your case, any other BIP0038 client.

Ente