Most of us know about the paper wallet but there are a few new products on the market that take bitcoin cold storage to the next level.Mike Ward takes a look at some of the latest storage options that won't go soggy in a flood.Cold storage solutions are simply ways of storing value such that the value is not accessible from any online computer.Generally speaking the idea is to trade your dependence on computer and network security for a reliance on physical security measures, which are better understood and less complex.The simplest example is the classic "paper wallet" which consists of a piece of paper with a private key and public address printed on it.Printing a QR code or two on the paper is not a bad idea either.Simply save the file to a thumb drive and load it on a machine which is not on the network.Generate a wallet there and print onto paper.As you can probably guess from that description these are susceptible to theft.Whether the thief takes possession of the paper, or simply takes a photograph of the private key or the QR encoding of it, they can then spend the money from that paper wallet.

There are more sophisticated variants of this simple scheme which offer better protection against theft.Specifically, any scheme which allows you to "break up" your private key into multiple, perhaps even redundant pieces will let you use more than one sheet of paper to store these chunks.bitcoin coffee shop londonThere are tricky ways to do this, and then there's the old reliable "tear the paper in half" method.bitcoin atm map ukRegardless how exactly this is done, it allows you to store them separately, and requires an attacker to have possession of more than a single piece of paper in order to spend from your wallet.ethereum analystHowever, physical damage can be a major issue for paper wallets.bitcoin pool url

They are particularly vulnerable to all manner of weather-related threats such as water damage and fire.At Bit-Card.de they offer a paper wallet product with some really attractive designs and fancy security holograms covering the private key.bitcointalk marketplaceThey produce an eye-pleasing, more durable plastic card version of the traditional paper wallet and in the last year have produced an encrypted card, which does not allow your private key to be known by them or any third parties.bitcoin gtx 1060More Durable Paper Wallet Options The good folks at CryptoCards.ca sell a Crypto Card that's made from scratch-resistant anodized aluminum, available for a variety of coins.bitcoin farmer virusTheir process correctly requires you to generate your encrypted private key on your own and upload it.cours bitcoin 2017

This eliminates the need to trust them with your private key, as well as trusting them to keep their server and software secure, etc.The keys and QR codes are etched into the surface of the card, so it's significantly more durable than paper.litecoin listed on coinbaseAnodized metal is resistant to rust and corrosion, so unlike paper these will not be ruined by exposure to water.These are probably not going to survive a fire, but of course the paper and plastic alternatives won't either.Finally there is the Cryo-Card from the labs of Cryobit.This is a high-tech solution designed by their chief scientist Cody Maher, an aerospace engineer by training.It's a credit card sized brushed metal device with your public key and QR code on the front, and your encrypted private key displayed on back.Like the Crypto Cards, you must generate and encrypt your private key before sending to them, so there's no danger of exposing this.

It is never recommended to allow anyone else to have access to your private key, since that alone allows spending from the corresponding public address.We're going to go easy on the materials science behind this product.Suffice to say that instead of scratching a pattern into the outer layer of metal, a ceramic glass substance is chemically bonded to it.The base metal for the Cryo-Card is aerospace grade AMS 5524 Stainless Steel designed to be anti-corrosive and scratch resistant as well.According to Maher, "To scrape off or remove the ceramic used to produce the QR codes with chemicals or abrasion you would need to remove the layer of metal beneath the ceramic as well."And Cryobit claims on their website that this card is heat resistant up to an amazing 2500℉ (1370℃).The company has another product ready for launch which is a gold colored Cryo-Coin designed for the same purpose.Maher claims they are gearing up for a Dogecoin version of the Cryo-Card, ready for sale in as little as a couple weeks.

The bottom line for paper wallets at this point in time is that they remain a good idea if, and only if implemented with a secure strategy.Simply printing pieces of paper and stuffing them into your dresser drawer is not sufficient security for any significant amount of bitcoin.Consider instead a durable form factor like the Cryo-Card that will withstand what mother nature can unleash, and is of no use to would be thieves since the private key is encrypted.If you read this post you probably have already purchased bitcoins from a bitcoin ATM and instead of using your own previously created wallet address you let the machine generate one for you.If you are still planning to buy bitcoins from a bitcoin ATM you might want to use our bitcoin ATM map to find a location or check our tutorial on how to buy bitcoins from bitcoin ATM.Not all bitcoin machines support generating and printing of address on receipts, many don’t even support printing receipts at all.So here is a list of known bitcoin ATM types, which can generate and print a paper wallet for you: All Genesis Coin ATMs (Genesi1, Satoshi1, Satoshi2) can do this: Also General Bytes two-way BATMThree model (one way BATMTwo doesn’t support it), BitAccess machines and BitXatm bitcoin ATM can generate and print receipt with bitcoin wallet address: When you use one of these machines and choose an option to generate address for you (you don’t have your own wallet) machine will print a brand new paper wallet for you at the end of the process or before the purchase, which normally will contain a public key (at the top) and a private key (at the bottom).

Similar to this one: At some bitcoin ATM models, like BATMThree for example, public key is located at the bottom on opposite, but it should be clear where is what from the hint text on the receipt.As you already know – a public key (actually it is a bitcoin address in this case, which is a changed form of a public key) is something you can show to others (in this case they will be able to not only send funds to this address, but also see a balance – it is like watch access only).However, private key is something you need to keep very secretly as anybody who has access to it can use and send bitcoins from this address, so don’t share it with others.It is a general practice to sweep bitcoins from such a receipt as soon as possible and it is highly not advisable to use such receipts as a form of paper wallet storage.Bitcoin address was generated by a bitcoin ATM which you cannot control, so in case the machine was compromised – potentially there is a vector of attack to access your funds.

So sweep bitcoins from receipt as soon as you get your own wallet, or you have address where to send them, e.g.to pay for something.It is also important to understand a difference between importing a private key and sweeping it, and we recommend always to sweep your bitcoins from printed private key because when you import a key, bitcoins are still controlled by the same key, although now you can use your wallet to handle them.Sweeping on opposite sends bitcoins to a new address, which is controlled by a new private key.So that means if somebody has access to private key printed by bitcoin ATM, they won’t be able to use your bitcoins anymore, which is not the case when you just import the key.So now you probably ask yourself – how can I use bitcoins from this receipt.What we recommend is to use one of the mobile wallets available.Depending on which phone you use you can choose either Mycelium for Android platform or Breadwallet for iOS, these are two mostly recommended for the two mostly used mobile OS.

Read how to use a wallet for Android phone in order to import private keys in the next section.In order to find details about iPhone wallet, jump to Breadwallet section.Before you proceed with sweeping bitcoins, you need to install Mycelium app and create your wallet there, which will be done by default.It is recommended to make a backup of your wallet before your first use (which is available via context menu and is basically writing down your seed words and store them safely), which will guarantee that if you lose your phone or de-install the app, you will still be able to recover your bitcoins from the wallet.So first you need to choose an account you want to use (by default you have only one account): So now when you have wallet created click Menu on top right and choose “Cold Storage”: You will be displayed with a description and several options, you need to click on “QR code” button: Now you need to scan a private key from your receipt (the one which is usually at the bottom of the receipt), when it is scanned information with address and balance will be displayed.

This information relates to how many bitcoins you purchased from bitcoin ATM, now click Send button: In the list of options choose My Addresses and when you confirm the funds will automatically be sent to one of addresses in the account you just created: If you have several accounts you need to choose one and define the amount of bitcoins to sweep (use “Max” button to transfer all): Choose Send on the next screen: So now bitcoins are safe and only you have access to control over them.You can send or pay with bitcoins using your Mycelium wallet later on.The full process can also be seen on the following video: Breadwallet is a popular wallet for iOS system.You can find it in Apple store in order to install.During the start-up steps the wallet will ask you to write down seed words.You can postpone it, but we highly recommend to do it from the beginning.When you open your wallet click on menu (top left): And then choose “Import private key”.The name is a bit misleading, because what Breadwallet app does in this case is actually sweeping private key (sending bitcoins to a new address within the wallet), but not actually importing it.