A Unique Shift in the Modulo Mix
Unfortunately, this puzzle requires you having the 10 NFC tags I am programming. I am attaching my full notes and solutions to this puzzle.
Description: Welcome to the modern era of physical security and access control. Before you lie ten NTAG215 NFC tags, physically numbered 1 through 10. One of these tags contains the system override phrase. The other nine are decoys.
Reading the tags is the easy part; understanding them is the true test. The data payloads on these tags are obscured. To reveal the true messages, you must realize that the hardware itself holds the key. The cipher changes from tag to tag, bound by the physical identity of the chip and the current era.
Your Objectives:
Interrogate the Hardware: A standard smartphone tap will only show you the encrypted text. To find the key, you must use a Flipper Zero, a Proxmark3, or an advanced smartphone application like NFC Tools to pull the complete hardware profile of the tags. Look deeper than the NDEF record.
Break the Encryption: Discover the mathematical relationship between the tag's deepest hardware secret and our current timeline to determine the shift and crack the cipher.
Process the Intelligence: If you successfully decrypt a decoy tag, the resulting text will provide a definitive, logical rule about the physical number written on the winning tag.
Rules of Engagement:
You have exactly FIVE (5) attempts. A proctor must be present and will log every physical tag you choose to scan.
If you exhaust all five attempts without securing the override phrase, you are permanently locked out of the system.
Do not rely on blind luck. Tap a tag, extract the hardware data, crack the cipher, and logically eliminate the remaining targets on the table.
Trust the math, not your luck.
Points: 150