⏺ What is a cold wallet

• Cold wallet is one type of the blockchain wallets. Corresponding with hot wallet, it refers to the wallet where the user's private key disconnects from the Internet, so it is also called offline wallet or disconnected wallet. Cold wallets usually rely on "cold" devices (such as computers and mobile phones that are not connected to the Internet) to ensure the security of Bitcoin private keys, and use QR code communication to keep private keys against accessing the Internet, avoiding the risk of being stolen by hackers. However, it also faces physical risks (e.g., loss of computer, damage).

• Store the private key on a device that is not connected to the Internet, including printing and writing it by hand (paper wallet), or even reciting it by yourself (brain wallet), to ensure absolute security during the process of storage. However, when you use the above wallets to conduct transactions, you still have to import the private key to the general software wallet, and the highest standard cold wallet must also be able to perform offline signing, and only send out signed transactions.

• The private key can be stored in an additional special hardware device, and the transaction needs to be signed within the hardware before submission. As long as the hardware is not cracked, it is absolutely safe. If this hardware device is completely offline and only submits signed transaction messages, it is a cold wallet with the highest standard.