What is a seed phrase?

Seed Phrase Definition – A seed phrase, or recovery phrase, is a series of 12, 18, or 24 random words generated by a cryptocurrency wallet that can be used to recover access to the wallet if it is lost or deleted.

When a cryptocurrency user sets up a new wallet, the software generates a seed phrase to provide initial access to the wallet as well as the private keys that allow them to send and receive cryptocurrencies and non-fungible tokens (NFTs).

If the user changes or loses their device, the device becomes corrupted, or they delete the wallet, they can use the seed phrase to regain access to the wallet.

As each cryptocurrency supported by a wallet has its own private key, the seed phrase acts as a master password, or key, to gain access to all a user’s private keys.

The seed phrase is the only backup, so if a user loses their seed phrase, they lose access to the wallet and all the cryptocurrency contained in it.

The seed phrase must be kept safe to prevent the cryptocurrency in the wallet from being stolen, as anyone who has the phrase has access to the wallet. The wallet will typically recommend writing down the seed phrase on a piece of paper rather than storing it on the device or online, where it is vulnerable to hackers.

Seed phrases were introduced with Bitcoin Improvement Proposal (BIP) 39 in 2013 when Bitcoin was the only cryptocurrency, but they are not specific to any one cryptocurrency. With the proliferation of alternative coins (altcoins), they apply to most cryptocurrency wallets, which can hold hundreds of coins and tokens.

A seed phrase represents a long string of random numbers. It is presented as a string of words rather than a numeric list because it is easier for people to interact with but still hard for attackers to crack the sequence. Each seed phrase based on BIP-39 is compiled from a list of 2,048 simple words.

A seed phrase with a minimum of 12 words has 128 bits of security, so a hacker would have to perform 2,128 operations to crack it.

If a user buys and holds cryptocurrency on an exchange they do not need an independent wallet. However, to keep their coins and tokens secure, they should consider moving some to a wallet to protect them from malicious attackers.

There are several different ways to keep a seed phrase secure.

It can be copied down and stored in more than one location, divided up and stored across multiple safe deposit boxes, or engraved onto a steel plate or capsule. It is not recommended to store it in a computer, mobile device, or external hard drive, as someone else can easily access them.

What is a BIP-39 seed phrase?

BIP-39 refers to the update to the Bitcoin blockchain in 2013 that introduced seed phrases to wallets. It is the most frequently used standard for seed phrases in cryptocurrency wallets. Seed phrases are not specific to any one cryptocurrency. They are used for wallets that can hold hundreds of different cryptocurrencies and non-fungible tokens (NFTs).