Keystore File

Cryptocurrencies rely on public-key cryptography, where a public key is used as a digital wallet address for sending and receiving cryptocurrencies, while a private key is used to prove ownership of the wallet and to validate outgoing transactions from that address with a digital signature.

A keystore file is an encrypted version of a private key which can be password protected and used in its place. Keystore files are files with JSON (JavaScript Object Notation) format, with the filename usually in UTC + format. It's common to see a keystore file referred to just as "JSON" or ".json".

There are 2 main benefits of keystore files:

1. Usability: ​Private keys are long strings of letters and numbers that aren't practical to memorize, so keystore files can improve wallet usability by enabling wallet owners to access their wallet and move funds with a password of their choosing.
2. Security: Hackers who are trying to steal cryptocurrency would need both the keystore file and the associated password in order to gain access to a digital wallet, whereas an unencrypted private key can be used on its own to access a wallet.

Most major cryptocurrency wallets give users the ability to use a keystore file.