"That's how all hardcover books are," He Ao said as he completed the transfer and took the book from Roger. "The inner layer of the cover is cardboard, with a layer of calfskin, fabric, or heavy paper on the outside. It makes the book easier to preserve and look more expensive."
He Ao flipped through the book in his hands. "For example, this book's cover is cardboard wrapped in a layer of printed heavy paper."
"Every trade has its tricks."
Roger laughed.
Then he led He Ao out to the storefront, took a black metal strip about one centimeter wide and two centimeters long from a drawer, carved with cloud patterns, and tossed it to him.
"What's this?"
He Ao caught the metal object. With a light press, three parallel metal contacts slowly emerged from one end.
These three contacts were the Federation-standard data transfer interface. They came with magnetic attachment and were generally used for data transmission between devices. He Ao's Smart Bracelet also had these three contacts, though they were hidden.
It looked like some kind of digital device.
"An Encrypted currency hardware wallet," Roger said as he drove He Ao out of his little shop.
"You can store your private key in this hardware wallet. Use it directly for verification when making payments or transfers. Touch those contacts to your bracelet, and you'll be able to see the instructions for using this thing."
In the Copy World, cryptocurrency was a general term for decentralized currencies that used cryptographic principles to ensure transaction security and control the issuance of currency units.
At its core, cryptocurrency was no different from the toy money children played with.
However, because its total supply was fixed and transactions were highly confidential, it could, in a sense, serve as a general equivalent or