At the first site, the terminal refused her USB stick. Its screen displayed a terse message: "Package unsigned." Maya sighed and placed the tag against the reader out of habit. The terminal blinked, and a secure channel opened. A tidy prompt asked for a one-time code; the tag pulsed once and emitted a string of characters like a heartbeat. The terminal accepted the code and then reached out over the encrypted link to fetch "NFC PM Pro" from the vendor's distribution server.


