Your Bitcoin private keys are crucial to storing and retrieving your Bitcoin. Without them, you have no hope of ever recovering your funds, and if someone else got hold of them, the results could be disastrous. Here’s how you can keep your keys secure no matter what befalls them.
Never Store Your Private Keys Digitally
If you store your private keys online, there’s a chance someone could access them, or you could accidentally reveal them. If you use online storage services such as Dropbox or Google Drive, you can share files with anyone in less than 30 seconds. This makes it easy to accidentally share your spreadsheet or document listing these precious keys.
Anything you store online is at the mercy of the storage provider. Sure, you could put this on the blockchain, or perhaps you trust Google et al. implicitly. Storing keys with another entity is fraught with danger. They could go bankrupt tomorrow, taking your keys with them. Perhaps your account gets hacked or you leave it logged on at a public library. No matter how it happens, online storage facilities present so many attack vectors that it’s not worth it, even if you encrypt your keys first.
Some go as far as never letting your private keys even reach a computer. The thinking is that any computer could get hacked, infected with a virus or malware, or become corrupted. This is a reasonable concern and most hardware wallets such as the Ledger Nano S come with a physical sheet of paper to write your keys on. Let’s see how to protect this flimsy physical key to your kingdom.
Hide Your Bitcoin Private Keys
To protect your private keys, you need to protect the paper containing their details. This needs to allow you easy access, make it difficult for others to find and use yet also remain protected in case of disasters such as fire or flood.
The following methods show you how to protect your keys with many redundant copies, but the first step is a good hiding place.
Providing you don’t house share (but even then you may have your own room), the biggest concern with written private keys is physical security. While it’s unlikely criminals will target you for your Bitcoin, a regular robbery or even opportunistic visitor may cause you concern.
Any thief breaking into your home is looking to find valuables as quickly as possible and then get out of there. While some hiding spaces may appear safe on the surface, criminals often know where to look for valuables.
Here are bad places to store your private keys:
- Inside kitchen food packages
- At the back of a drawer
- Under the doormat
- Inside a fake plant
- At the back of the wardrobe
- In a cheap safe
- Inside a coat pocket
- In/next to/near valuables such as games consoles
- Behind your television
- In the toilet cistern
Many of these hiding spaces seem safe on the surface, but they aren’t. Would-be robbers want valuables and fast. Games consoles and television sets are prime targets, as are jewellery boxes and draws. Many people hide valuables in their bedside units or underwear drawers, so that’s the first place many thieves will look.
You may think the back of the wardrobe is a good hiding place, behind lots of boxes. This isn’t. While you may attach value to all these boxes and carefully remove each one, criminals don’t and can remove them all in a matter of seconds. Equally, cheap safes may deceive you. If it’s not hidden and bolted down, criminals can take the whole thing to open later. You’d also have to secure the key for any safe you do use. Safes are only worthwhile if you can afford a large, premium model, but often this screams “I’ve got something worth taking”.
How about these for some good hiding places (but don’t use these, think of your own unique spaces):
- Under a floorboard (screwed down)
- Behind the wallpaper
- Inside a wall cavity
- Behind a kitchen unit/under the counter
- Buried (deep!) in the garden
Taped to the back of cabinets or drawers is a good hiding place. These are not immediately visible if someone flings the doors open and rifles through the contents, yet still remain somewhat accessible. Good hiding places are not immediately obvious and are not accessible in the time it takes for a robbery to happen. If it’s difficult for you to access, that makes it difficult for a criminal to access!
As you’ll see in the following tips, a good hiding space combined with careful management leads to a good private key storage mechanism.
Split Your Private Keys Between Many Sites
If you store one copy of your private keys in your house, you run the risk of losing everything and not just to theft! If there’s a fire, flood, or natural disaster, your one and only copy of your private keys could be gone in an instant.
By creating several copies of your private keys, you can distribute these in many locations to increase redundancy. You could store one at home, one at work, one in the shed, and one with a family member. Try to ensure each copy is in a different physical location, and not the same building.
If you don’t trust family members or your office is not secure, you can protect your keys even further. Split the keys up so that each trustee only has access to a subset of the keys. If the key is A > B > C, I could keep A, give B to Gavin, and C to Dan. The only way to get the whole key is by using all three people. There’s no limit to how far you can split your keys, but you may need many locations to ensure you have enough redundancy.
If you store 50 percent of the key and a friend stores 50 percent, you’re no better off than before, with a single accident destroying your access. Split your keys up, and store many (smaller) copies in many different locations.
Use a Fire and Flood Proof Medium
If your keys live on a piece of paper they can get destroyed by flood or fire. Many unique products exist to protect against this.
You could start with a fire-proof and water-resistant document safe, making sure to bolt it down to prevent someone taking the whole lot. This would mean your keys can survive most disasters. When combined with multi-part key storage, as shown above, you can really secure your keys.
It’s possible to buy sheets of metal and letter presses designed to store your private keys. By stamping the words for your keys on a piece of metal, there’s no way they will get destroyed in a catastrophe.
Keep Your Bitcoin Private Keys Safe!
By taking your Bitcoin off the exchange and storing it yourself, you’re already a big step towards keeping your funds safe. These tips for securing your private keys are some of the best ways to take security one step further.
By using a combination of these tricks, you can protect your private keys from the elements and ensure nobody but you can use them. Don’t forget about these common cryptocurrency scams, which can still happen no matter how secure your private keys are.