Before holding any bitcoin, you need somewhere to store it. Just like in the physical world, you store your bitcoin in a wallet.
Similar to a bank account number, your wallet comes with a wallet address that shows up in a ledger search and is shared with others so you can make transactions. This address, which is a shorter, more usable version of your public key, consists of between 26 and 35 random alphanumeric characters, something like 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa. Keep in mind that every letter and number in that address is important. Before sending any bitcoin to your wallet, double-check the entire address, character by character.
Also tied to your wallet address is one or more private keys, which as the name suggests should not be shared with anyone. Keys are used to verify you own the aforementioned public key, and to sign off on transactions. Some wallets create a secure seed phrase, a set of words that will allow you to unlock your wallet if you lose your keys. Print this phrase out and keep it in a safe place.
The unfortunate truth is your bitcoin wallet is akin to your physical wallet. If you lose the private keys to your wallet, you’re most likely going to lose the currency in it forever.
Your wallet generates a master file where your public and private keys are stored. This file should be backed up in case the original file is lost or damaged. Otherwise, you risk losing access to your funds.
You can store your private keys on your computer, mobile device, on a physical storage gadget or even on a piece of paper. It’s crucial that you keep your private keys safe by generating backups both online and offline.
Remember: Your wallet does not reside on any single device. The wallet itself resides on the Bitcoin blockchain, just as your banking app doesn’t truly “hold” the cash in your checking account.
While wallet apps work well and are relatively safe, the safest option is a hardware wallet you keep offline, in a secure place. The most popular hardware wallets use special layers of security to ensure your keys are not stolen and your bitcoin is safe. But, once again, if you lose the hardware wallet your bitcoins are gone unless you have kept reliable backups of the keys.
The least-secure option is an online wallet, i.e. storing your bitcoin in an exchange. This is because the keys are held by a third party. For many, the online exchange wallets are the easiest to set up and use, presenting an all-too-familiar choice: convenience versus safety.
Many serious bitcoin investors use a hybrid approach: They hold a core, long-term amount of bitcoin offline in so-called “cold storage,” while keeping a spending balance in a mobile account.
Depending on your bitcoin strategy and willingness to get technical, here are the different types of bitcoin wallets available. Bitcoin.org has a helper that will show you which wallet to choose.
Cloud wallets exist online and the keys are usually stored in a distant server run by a third party. Cloud-based wallets tend to have a more user-friendly interface but you will be trusting a third party with your private keys, which makes your funds more susceptible to theft. Some examples of this wallet type are Coinbase, Blockchain and Lumi Wallet. Most cryptocurrencies, including bitcoin, have their own native wallets. Some offer additional security features such as offline storage (Coinbase and Xapo).
With your private keys stored on a server, you have to trust the host’s security measures and also trust the host won’t disappear with your money or close down and deny you access.
Software wallets can be installed directly on your computer, giving you private control of your keys. Most have relatively easy configuration and are free. The disadvantage is you are in charge of securing your keys. Software wallets also require greater security precautions. If your computer is hacked or stolen, the thief can get a copy of your wallet and your bitcoin.
While you can download the original software Bitcoin Core protocol (which stores a ledger of all transactions since 2009 and takes up a lot of space), most wallets in use today are “light” wallets, or SPV (Simplified Payment Verification) wallets, which do not download the entire ledger but sync to it.
Electrum is a well-known SPV desktop bitcoin wallet that also offers “cold storage” (a totally offline option for additional security). Exodus can track multiple assets with a sophisticated user interface. Some (such as Jaxx Liberty) can hold a wide range of digital assets, and some (such as Copay) offer the possibility of shared accounts.
Before downloading any app, please confirm you are downloading a legitimate copy of a real wallet. Some shady programmers create clones of various crypto websites and offer downloads for free, leading to the possibility of a hack.
Mobile wallets are available as apps for your smartphone, especially useful if you want to pay for something in bitcoin in a shop or if you want to buy, sell or send while on the move. All of the online wallets and most of the desktop ones mentioned above have mobile versions, while others – such as Abra, Edge and Bread – were created with mobile in mind. Remember, many online wallets will store your keys on the phone itself, leading to the possibility of losing your bitcoin if you lose your phone. Always keep a backup of your keys on a different device and print out your seed phrase.
Hardware wallets are small devices that connect to the web only to enact bitcoin transactions. They are more secure because they are generally offline and therefore not hackable. They can be stolen or lost, however, along with the bitcoins that belong to the stored private keys, so it’s recommended that you backup your keys. Some large investors keep their hardware wallets in secure locations such as bank vaults. Trezor, Keepkey and Ledger are notable examples.
Paper wallets are perhaps the simplest of all the wallets. Paper wallets are pieces of paper that contain the private and public keys of a bitcoin address. Ideal for the long-term storage of bitcoin (away from fire and water, of course) or for the giving of bitcoin as a gift, these wallets are more secure in that they’re not connected to a network. They are, however, easier to lose.
With services such as WalletGenerator, you can easily create a new address and print the wallet on your printer. When you’re ready to top up your paper wallet you simply send some bitcoin to that address and then store it safely. Whatever option you go for, be sure to back up everything and only tell your nearest and dearest where your backups are stored.
For more information on how to buy bitcoin, see here. And for some examples of what you can spend it on, see here.
(Note: Specific businesses mentioned here are not the only options available, and should not be taken as an official recommendation. Further, companies could go out of business and be replaced with more nefarious owners. Always protect your keys.)
The rise of quantum computers could eventually pose an actual security threat to Bitcoin’s encryption, where private keys could be determined from public keys, but there are already known methods that the Bitcoin protocol can adopt when necessary in order to become more quantum resilient, since the blockchain can be updated when there is broad consensus among participants.