Public & Private Keys Explained
📖 5 min read
Quick Answer
比特幣用一對金鑰取代了用戶名和密碼。一個你可以與全世界分享，另一個你必須用一輩子守護。它們一起讓您可以公開收款並私下消費，中間沒有銀行。
💡 Think of it as…
街上的玻璃信箱。任何人都可以看到裡面並透過投信口投一封信（您的公共地址），但只有您持有打開門並取出信件的鑰匙（您的私鑰）。每個人都可以付錢給你；只有你可以花。
Private key: your secret
私鑰是隨機產生的秘密數字。它證明所有權並用於“簽署”交易。持有私鑰的人就控制著這些代幣——這就是為什麼失去私鑰就意味著失去存取權限，而洩漏私鑰就意味著失去資金。
Public key & address: your handle
Your public key (and the address derived from it) is shared freely so others can send you Bitcoin. Crucially, the public key can be calculated from the private key, but never the other way around — thanks to one-way cryptography.
數位簽名
When you spend, your wallet uses the private key to create a signature that anyone can verify with your public key — proving you authorized the payment without ever revealing the secret. No signature, no spend.
🔑 Key takeaway
Public key = receive (share it). Private key = spend (protect it). The math lets the network verify your payments without ever seeing your secret.
Why this matters for you
This is why self-custody matters: a hardware wallet keeps your private keys offline and in your hands, beyond the reach of exchange hacks, frozen accounts, or capital controls — a real concern for savers across Asia.
常見問題
What is a seed phrase then?▼
種子短語（12 或 24 個單字）是人類可讀的備份，可以重新產生您的所有私鑰。像鑰匙一樣保護它——任何擁有您的助記詞的人都可以控制您的比特幣。
如果我的地址是公開的，我的餘額也公開嗎？▼
Yes — anyone can look up an address’s balance and history on the public ledger. That is why privacy-conscious users avoid reusing addresses.
What happens if I lose my private key?▼
The coins are permanently frozen on the blockchain — no one can recover them, including you. This is the trade-off of being your own bank, and why backups matter.