01 Token’s past and present
Before it was used in the blockchain, Token already existed in network communication. The original meaning was “token, signaling”.
在以太网成为局域网的普遍协议之前，IBM曾经推过一个局域网协议，叫做Token Ring Network，令牌环网。网络中的每一个节点轮流传递一个令牌，只有拿到令牌的节点才能通讯。这种令牌可以理解成一种暗号，而暗号被授权一定的操作权限，只有暗号对得上，你才有权利行使这部分的操作权限。
Before Ethernet became a universal protocol for LANs, IBM had pushed a LAN protocol called Token Ring Network. Each node in the network passes a token in turn, and only the node that gets the token can communicate. This token can be understood as a cypher, and the cypher is authorized for certain operation authority. Only when the cypher is correct, you have the right to exercise this part of the operation authority.