I recently came across an interesting news story: authorities are still cracking the cold wallet of a certain politician. This made me think that many people actually don’t understand what a cold wallet is or why everyone says it offers the highest security.

In fact, cryptocurrency wallets are completely different from bank accounts. They are not places where assets are stored; rather, they are digital tools that allow you to deposit, send, and receive virtual assets. Simply put, a wallet is like a passport in the blockchain world, representing your identity. You need it to operate within this ecosystem.

The core of a wallet consists of three things: private key, public key, and address. The private key is the most critical—it’s a 256-bit random number used to prove you are the owner of the wallet. As long as someone knows your private key, your assets are at risk, so it must never be leaked. The public key is a marker used by miners to identify your wallet, and the address is your location on the blockchain, used for sending and receiving assets.

Wallets are divided into two main types. Hot wallets are connected online, such as exchange wallets and browser plugins like MetaMask. They make transactions convenient, and a few steps are enough to withdraw funds, but because they are always online, they are more vulnerable to hacking. Especially with centralized exchanges, even though the wallet appears to be yours, the actual control is not in your hands—it's like entrusting your assets to the exchange. The FTX bankruptcy case illustrates this: even if the wallet is yours, you can’t get your assets back if the exchange goes bankrupt.

In contrast, cold wallets are the real security fortress. Cold wallets are physical devices like hard drives or USBs, stored offline, with private keys completely disconnected from the internet, making it nearly impossible for hackers to steal them. Common brands include Ledger and Trezor, priced around $100 to $250. Even if you lose or damage the hardware, as long as you remember your private key and recovery phrase, you can restore your assets because the assets themselves are stored on the blockchain; the cold wallet is just a tool to access them.

When buying a cold wallet, be sure to order directly from the manufacturer. Upon arrival, check that the packaging is intact—some malicious actors might pre-install malware.

How to choose? If you trade frequently, hot wallets are necessary; MetaMask or Trust Wallet are good options. But if you hold large amounts of assets or plan to hold long-term, a cold wallet is the safer choice. Data shows that after FTX’s collapse, over 450k Bitcoin were transferred from a major exchange to cold wallets in 2022. Investors are clearly more inclined to manage their assets themselves. During times of high market risk, no one dares to gamble on the security of exchanges; storing assets in cold wallets is the smartest move.