Bip39 Seeds and Ethereum Keys
Some accounts are created using Bip seed phrases - special kinds of phrases that can generate private keys. The tool I recommend generates a type of Bip phrase called a Bip39 seed phrase. Bip39 seed phrases are a standard in the cryptocurrency community and are used across a number of software and hardware wallets (including MyEtherWallet and Ledger Nano S).
You can think of Bip39 seed phrases like this:
seed + password + HD Path => private key private key => public key public key => public address
A single Bip39 24 word seed phrase with a Bip39 password/passphrase, along a particular path (called an HD path) will produce a particular private key.
That private key will then produce a public key.
That public key will then produce the public address.
Here is a standard 24 word Bip39 seed phrase.
gravity trophy shrimp suspect sheriff avocado label trust dove tragic pitch title network myself spell task protect smooth sword diary brain blossom under bulb
Using this password:
And this HD (hierarchical deterministic) path:
We will derive this Ethereum private key:
Which will then derive to this Ethereum public key:
Which will derive to this public Ethereum address:
(Do not use this account for any real funds...you will lose everything you put in there.)
In order to steal the funds out of a wallet, someone needs to know the Bip39 seed phrase, and the password. Then they can just guess all the various HD paths (there are not that many options) until they get the private key.
Once they have the private key, then and only then can they attempt to take all the funds within the wallet.