the original passage.

Everyone can see the key that carries a request. Only the holder of a private note can spend its value. The book address below is the public identity used when the contracts were created. It does not hold user secrets, and it is not the zc token.

The zc token contract for this site is

Payments still move through the shared book terminals described on the home page: a public identity carries the request, a private proof authorizes the spend, and a separate sponsor pays the relay gas.