Bitcoin wallets. What are they?

Bitcoin Wallets let us send, receive and store Bitcoin amounts all the way down to the Satoshi unit.

Wallets secure funds by guarding our private keys. These private keys act as the proof of ownership for our Bitcoins. As such, a Bitcoin wallet is like a key to your safe deposit box on the Blockchain.

What is a private key?

Private keys emerged as a way to communicate securely through insecure communication channels.

Historically, before the advent of public key cryptography, the greatest cryptographic weakness was the inability to communicate the ‘key’ that makes sense of encrypted messages. As a solution, the use of two keys (public and private) entered the picture.

It’s a nifty little trick.

Keys come in pairs. The public key is used to encrypt the message whereas the private key decrypts the message. The only person with the private key is you. Everyone else is free to have your public key. As a result, everyone can send you encrypted messages without having to agree on a key beforehand. They simply use your public key and you untangle the gibberish by using your private key.

Why should I care about private keys?

At the end of the day, all of this can go over your head without much danger. Just remember that it’s good to know what you’re dealing with. Bitcoin wallets make use of a fundamental cryptographic principle that we use for things ranging from https for websites or sending anonymous tips to Wikileaks. Most importantly, by understanding private keys you’ll have a much easier familiarizing yourself with Cold Storage wallets.

What is a Bitcoin address?

A Bitcoin address is like an account number, just better. The address denotes which wallet the coins should be sent to. Like a bank account number, where the difference lies in the wallets having multiple addresses. These can be customized by including payment request information such as an amount and a date of expiration.

What should I know about addresses?

Bitcoin wallet addresses are case sensitive, usually have 34 characters of numbers and lowercase letters, start with either a 1 or a 3, and never use 0, O, l and I to make every character in the address as clear as possible. That’s a lot to take in. But don’t worry. What they consist of is largely irrelevant to you. Just know they’re a string of characters that denote a destination on the Bitcoin Blockchain.

How do I generate a Bitcoin address for my wallet?

How to generate a new Bitcoin Address varies between wallets. Some manage your addresses for you. Others give you full control. As with many other Bitcoin technologies, the option to dirty your own hands is always open.

If you do end up taking the easier route, just press a button to generate a new address for your wallet.

Some wallets, like Electrum, allow you choose in how many blocks your transaction should be confirmed. The faster you want your payment to go through, the more you will have to pay miners for confirming your activity. We find here another difference between Bitcoin wallets and Bank accounts. Given the right wallet, the control and oversight that we have over our transactions is far more extensive than that of the traditional banking system.

How do I fund a Bitcoin Wallet?

First, acquire some Bitcoins. Go through an exchange in your country, ask an acquaintance to share, or use Buybitcoinworldwide.com if you want as seamless of an experience as possible. The purchased coins can then be sent to your wallet by specifying one of its addresses.

Some wallets, particularly online ones, also let you buy coins. Keep in mind that these come with larger exchange margins which are best left alone.

Are Bitcoins safe?

Is Bitcoin a safe way to store value digitally? Are we wise to save our coins on our computer? It’s true that online wallets are necessarily more dangerous than offline wallets. However, even offline wallets can be breached, meaning that security in the Bitcoin world depends largely on following good practices. Just like you would avoid flailing your bills about in a dangerous place, you should make sure to keep your passwords and keys as safe as possible.

How do I secure my Wallet?

• Secure your computer
• Restrict unsupervised access. Set a strong password and close all ports and maintain a strict firewall.
• Frequently change address. Use a different address for every transaction.
• Multiple Signatures (Multi-sig). Multiple private keys to deter breaches.

Where are Bitcoins stored?

Bitcoins simply consist of a string of data. That’s why they can be stored anywhere. You could paint Bitcoin on a wall with your blood. Nobody does that though. Hopefully.

Instead, we store BTC on computers because we need them handy to trade. After all, we need to be connected to the internet to send value from one wallet to another over the Blockchain.

How do I open a Bitcoin account?

To some readers this might seem like a weird question. Truth is, people coming from a financial or business background are likely to expect Bitcoin to be a direct alternative to our current financial system. This is not the case.

You don’t need a Bitcoin account. There is no such thing really. You just need a wallet. The only accounts you might encounter are online wallets that are separated into various accounts via a user system.

What types of wallets are there?

• Online
  • Web-wallet. Accessed via web-browser. Access to money gained through username or password.
• Offline
  • Desktop
    • Access gained via physical access to computer.
  • Mobile
    • Access gained via physical access to phone.
• Hardware (Cold Storage)
  • Paper, Brain, Hardware
    • Hardware wallets delimit access of your funds to the hardware device alone. The coins are stored in a microcontroller, and are to be transferred only when authorized.
    • The act of storing of your wallet’s private keys in a way that is completely detached from a network.

How do I know which wallet is best for me?

Let’s be honest. It’s unreasonable to expect anyone else to make this decision for you. After all, your preference depends entirely on your personality and needs. So just be honest with yourself.

Frankly, you shouldn’t need anything complicated if you’re using the wallet for simple internet expenses or as a way to save money.

If, however, you’re planning to run a Bitcoin centered business make sure to use advanced wallets that support automated mass payments.

Any common mistakes to be careful of?

First of all, don’t rest your money in an exchange wallet. Keep your coins in an environment where you have complete control.

Secondly, don’t keep all of your coins in one place. You’ll be crushed if you lose access to a wallet with all of your funds.

Thirdly, double check the target address. Bitcoin transactions cannot be reversed, so don’t lose your coins forever to a stranger!

Last of all, use trusted online wallets (if at all). Don’t just trust anyone with your money. Make sure that the online wallet provider has a reputation of upholding the highest possible security standards.

Security Risks with Hardware Wallets

Hardware wallets are more secure than any other software wallet, like one that runs on your Android or iOS device, or desktop. However, hardware wallets have some unique security risks to be aware of.

Tampering of the Device

We always recommend to order directly from the hardware seller. This is because someone can buy a hardware wallet, tamper with it, and sell it used. They could program it to steal any bitcoins or add a back door.

Most hardware wallets add some special kind of tape on the packaging to try to make any tampering more noticeable. This is another reason we recommend only ordering from the hardware wallet company, and not from a website like eBay.

Bad Random Number Generator

Bitcoin private keys are based on cryptography. Random number generators, also called RNGs, are used to create the private keys that secure bitcoins.

If the random number generator is not random enough, that means someone else can recreate the private key of the hardware wallet easier. This attack has happened in the past with blockchain.info, a web wallet. Over 300 BTC were lost because blockchain.info did not use good RNG, so a hacker was able to generate the private keys again and steal coins.

One way to help prevent this is to use the hardware wallet’s custom 25th word. TREZOR, for example, allows you to add a 25th word to the 24 word seed. This means that you can technically add your own RNG to the computer generated RNG to ensure your private key will be truly based on good RNG.

What happens if the hardware wallet company goes out of business?

All hardware wallets listed above work with other wallets. So, if the hardware wallet company goes out of business you will still be able to use your wallet with a different wallet like Electrum.

Let’s say you use TREZOR with TREZOR’s myTREZOR wallet. TREZOR goes out of business and no longer supports myTREZOR wallet and it gets shut down.

You could, in just a few minutes, download Electrum on your computer. Once installed, you’d setup your TREZOR and all of your transaction history and balance would get imported and be exactly the same. This is because Electrum will use the same 24-word seed you generated with TREZOR on setup.

Which wallets can be used for each device?

Ledger Nano S, KeepKey and TREZOR all work with:

• Mycelium (Android version only)
• Electrum for Mac, Windows and Linux
• Multibit HD
• GreenAddress

Do these hardware wallets work for Ethereum?

Yes, all of these wallets work with Ethereum, Litecoin and many other coins.

TREZOR and Ledger both have blog posts explaining their integrations with various Ethereum wallets.

The hardware wallet tells me to write down the 24 word seed on paper.

Should I take a picture of the seed with my phone as a backup?

NO, NO, and NO!

The seeds generated by hardware wallets are meant to be written down only. By taking a picture of your seed with an internet connected phone, you put your entire wallet on a device that is connected to the internet and easier for hackers to get into. Please do not do this!

Why do the hardware wallets have buttons?

The buttons are used to confirm transactions. In order to send a transaction, you must physically press or hold buttons on the devices. This is a security feature. If a hacker were to access the hardware wallet somehow, the hacker still would not be able to send a TX without physical access to the buttons. Read more about this in TREZOR’s security philosophy.

Do hardware wallets work with Coinbase?

One of the most frequent questions we get asked is how Coinbase works with hardware wallets.

It’s a trick question!

Coinbase does not work directly with hardware wallet. You should, however, send bitcoins from Coinbase directly to your hardware wallet once you buy. Never store bitcoins on Coinbase or any other exchange for long periods of time.

Too many people in the past have lost money from hacks like Bitfinex and Mt. Gox.

So, yes, use a hardware wallet in conjunction with Coinbase. Buy on Coinbase, then send to hardware wallet.

Also, what we said above goes for ALL exchanges. Use Bitstamp? Cool! Once you buy bitcoins on Stamp, send the coins to your hardware wallet. The same goes for Kraken, Poloniex, or any other exchange or service that holds your coins!

What other kinds of wallets can I use?

Other wallet types are hot wallets. This means they are wallets run on an internet connected computer.

Android wallets, iOS wallets and desktop wallets are all examples of this.

How many backups of my seed should I create?

We recommend keeping at least two backups of your seed in multiple locations.

You can also laminate your seed to protect against water damage or any other damage.

Keeping your seeds in fire proof safes can help protect in the event that the storage location is burned down.

Another option is to put your seed into metal manually using stamps, or using cryptosteel.

What happens if someone finds my 24 word seed?

Unless you’re using a 25th word, someone who finds your 24 word seed can sweep your entire wallet.