What is a mnemonic?
Pronounced “ne-manik,” in its purest form a mnemonic is a pattern of letters, words, or associations which allows you to easily remember information, and has been used by humans for thousands of years. In other words, it can be a very useful tool to help us memorize important information we need to remember.
In bitcoin, mnemonics take on the same basic principles, which are using a group of words to generate a unique wallet phrase which gives you a human readable format of words to back-up your wallet for recovery. The mnemonic code for generating these phrases was introduced into bitcoin in 2013 in a Bitcoin Improvement Proposal or BIP. The proposal gave a distinct description of it as:
This BIP describes the implementation of a mnemonic code or mnemonic sentence — a group of easy to remember words — for the generation of deterministic wallets.
It consists of two parts: generating the mnemonic, and converting it into a binary seed. This seed can be later used to generate deterministic wallets using BIP-0032 or similar methods.
How is a mnemonic used in the Blockchain Wallet?
The mnemonic passphrase is provided to you when you sign up for a new Blockchain Wallet. The purpose of this is in case you need to recover your wallet at a later date, if you lose your login information.
When you recover your wallet with your mnemonic, your password and identifier will be displayed to you. Your main password cannot be changed once it is set, therefore your mnemonic will always remain the same for each wallet. To find your wallet mnemonic, log into your Blockchain wallet, go to Account Settings, and click on Passwords.
It’s recommended that you properly store your mnemonic along with your password and Blockchain identifier somewhere safe offline.