I noticed that Flipper Zero has a Detect Reader functionality which is supposedly used to capture some data from a NFC reader to crack the protection of a Mifare Classic card i.e. by using mfkey32. Afaik, this works by having F0 emulate a card and capturing the interactions (nonces). As I read the web I see that this approach has a high chance to trigger security tampering alarms on the readers. I think there was even a thread on Reddit about a guy who lost his job because of this.
Would it be possible to modify this “Detect Reader” functionality in such a way that would avoid triggering any alarms i.e. by having F0 passively eavesdrop on the interaction between the reader and a NFC card? This would of course require the user to own a valid Mifare Classic 1K card. The user would set F0 into NFC passive scan mode, place the NFC card on the back of it and then approach the reader with both devices. The reader will perform its stuff and register the card as normal, but F0 would passively sniff the interaction and capture the required data. This would definitely require the user to repeat the sniff a number of times over longer time period (i.e. daily checking in and checking out at work) to avoid triggering tamper alarms. Once sufficient interactions are recorded, proceed with the cracking as normal.
Can this be done?