KNOWsecurity
Always remember that it is your responsibility to adopt good practices in order to protect your money.
If you lose your bitcoins, they’re gone forever. There’s no 1-800 number or central authority to call to help resolve a problem. Be very careful who you correspond with online. Do not give out your private key or passwords. Watch out for email phishing scams. Take every precaution, as you would with your sensitive financial information. (pin numbers, social security number, account passwords, etc)
Small amounts for everyday uses
A Bitcoin wallet is like a wallet with cash. If you wouldn’t keep a thousand dollars in your pocket, you might want to have the same consideration for your Bitcoin wallet. In general, it is a good practice to keep only small amounts of bitcoins on your computer or mobile for everyday uses and to keep the remaining part of your funds in a safer environment.
Be careful with online services
Online wallets and exchanges look like online banks. However, you should always choose such services carefully. As of today, these services generally don’t provide enough insurance and security to be used to store your money like a bank. Using security features like two-factor authentication can help to increase the security of your accounts.
Backup your wallet
Stored in a safe place, a backup of your wallet can protect you against computer failures and many human mistakes. It can also allow you to recover your wallet after your mobile or computer was stolen if you keep your wallet encrypted.
Backup your entire wallet
Some wallets use many hidden private keys internally. If you only have a backup of the private keys for your visible Bitcoin addresses, you might not be able to recover a great part of your funds with your backup.
Encrypt online backups
Any backup that is stored online is highly vulnerable to theft. Even a computer that is connected to the Internet is vulnerable to malicious software. As such, encrypting any backup that is exposed to the network is a good security practice.
Use many secure locations
Single points of failure are bad for security. If your backup is not dependent of a single location, it is less likely that any bad event will prevent you to recover your wallet. You might also want to consider using different medias like USB keys, papers and CDs.
Make regular backups
You need to backup your wallet on a regular basis to make sure that all recent Bitcoin change addresses and all new Bitcoin addresses you created are included in your backup. However, all applications will be soon using wallets that only need to be backed up once.
Encrypt your wallet
Encrypting your wallet or your smartphone allows you to set a password for anyone trying to withdraw any funds. This helps protect against thieves, though it cannot protect against keylogging hardware or software.
Never forget your password
You should make sure you never forget the password or your funds will be permanently lost. Unlike your bank, there are very limited password recovery options with Bitcoin. In fact, you should be able to remember your password even after many years without using it. In doubt, you might want to keep a paper copy of your password in a safe place like a vault.
Use a strong password
Any password that contains only letters or recognizable words can be considered very weak and easy to break. A strong password must contain letters, numbers, punctuation marks and must be at least 16 characters long. The most secure passwords are those generated by programs designed specifically for that purpose. Strong passwords are usually harder to remember, so you should take care in memorising it.
Offline wallet for savings
An offline wallet, also known as cold storage, provides the highest level of security for savings. It involves storing a wallet in a secured place that is not connected to the network. When done properly, it can offer a very good protection against computer vulnerabilities. Using an offline wallet in conjunction with backups and encryption is also a good practice. Here is an overview of some approaches.
Hardware wallet
A hardware wallet is a special type of bitcoin wallet which stores the user’s private keys in a secure hardware device.
They have major advantages over standard software wallets:
- private keys are often stored in a protected area of a microcontroller, and cannot be transferred out of the device in plaintext
- immune to computer viruses that steal from software wallets
- can be used securely and interactively, as opposed to a paper wallet which must be imported to software at some point
- much of the time, the software is open source, allowing a user to validate the entire operation of the device
TREZOR is a secure bitcoin storage and a transaction signing tool. The private keys are generated by the device and never leave it thus they cannot be accessed by a malware.
It uses a deterministic wallet structure which means it can hold an unlimited number of keys (BIP 0032/BIP 0044). A recovery seed is generated when the device is initialized. In case TREZOR gets lost or stolen, all its contents can be recovered using this seed (private keys, bitcoin balance and transaction history) into a new device or another BIP 0039/BIP 0044 compatible wallet.
TREZOR also introduced a unique way of PIN entering preventing keyloggers from recording it even when entered on a compromised computer. An encryption passphrase can be set on top of the PIN protection. More passphrases can be used for plausible deniability.
Ledger Nano protects your Bitcoin data within a smartcard. Its micro-processor certified against all types of attacks (both physical and logical), and has been used in the banking industry for decades (think credit card chips). The device connects to your computer through the USB port and will do all the Bitcoin cryptographic heavy lifting such as signing transactions inside its secure environment. You can therefore use your Bitcoin account with maximum trust, even on an insecure or compromised computer.
The second factor verification of the transaction signature can be done either with a paired smartphone (Android, iOS) or a physical security card.
The Ledger Wallet Chrome application (available also on Chromium) provides an easy onboarding as well as a seamless user experience, and the Nano is compatible with numerous third party software: Electrum, Mycelium, GreenAddress, Greenbits, Coinkite and Copay.
Paper wallets
A paper wallet is a way to store Bitcoins that involves printing the Bitcoin addresses and private keys directly on a piece of paper. When done properly, paper wallets are one of the safest ways possible to store Bitcoins.
For long-term storage of bitcoins (or giving BTC as gifts) it can be risky to store your bitcoins in an exchange or online wallet. These types of sites have the possibility of getting hacked. Even keeping a live wallet on your own computer can be risky.
By printing out your own tamper-resistant bitcoin wallets and generating your own addresses, you can minimize your exposure to hackers as well as untrustworthy people in your home or office. Just transfer your bitcoins into your new wallets, and use common sense to keep your wallets safe the way you would jewels and ordinary cash. Or give them away!
Paper wallet generator visit bitaddress.org
How to video
Offline transaction signing
This approach involves having two computers sharing some parts of the same wallet. The first one must be disconnected from any network. It is the only one that holds the entire wallet and is able to sign transactions. The second computer is connected to the network and only have a watching wallet that can only create unsigned transactions. This way, you can securely issue new transactions with the following steps.
- Create a new transaction on the online computer and save it on an USB key.
- Sign the transaction with the offline computer.
- Send the signed transaction with the online computer.
Because the computer that is connected to the network cannot sign transactions, it cannot be used to withdraw any funds if it is compromised. Armory can be used to do offline transaction signature.
Hardware wallets
Hardware wallets are the best balance between very high security and ease of use. These are little devices that are designed from the root to be a wallet and nothing else. No software can be installed on them, making them very secure against computer vulnerabilities and online thieves. Because they can allow backup, you can recover your funds if you lose the device.
As of today, no hardware wallet has entered in production but they are coming soon:
Trezor.com
ButterflyLabs BitSafe
Keep your software up to date
Using the latest version of your Bitcoin software allows you to receive important stability and security fixes. Updates can prevent problems of various severity, include new useful features and help keep your wallet safe. Installing updates for all other software on your computer or mobile is also important to keep your wallet environment safer.
Multi-signature to protect against theft
Bitcoin includes a multi-signature feature that allows a transaction to require the signature of more than one private key to be spent. It is currently only usable for technical users but a greater availability for this feature can be expected in the future. Multi-signature can, for example, allow an organization to give access to its treasury to its members while only allowing a withdrawal if 3 of 5 members sign the transaction. It can also allow future online wallets to share a multi-signature address with their users, so that a thief would need to compromise both your computer and the online wallet servers in order to steal your funds.
Prepare for long-term
Your bitcoins can be lost forever if you don’t have a backup plan for your peers and family. If the location of your wallets or your passwords are not known by anyone when you are gone, there is no hope that your funds will ever be recovered. Taking a bit of time on these matters can make a huge difference.