Yubikey and NitroKey offer NFC and non-NFC versions of their flagship hardware security tokens (HSTs).
NFC is convenient, but can under some circumstances send e.g. challenge-response exchanges in clear text.
Smartcards using RFID, a similar though not identical protocol, can be queried from ~100cm away.
- Are there other ways are NFC HSTs are known to be more risky than their non-NFC counterparts?
- Should users store NFC HSTs in RFID-blocking pouches, like those used for wireless car keys or contactless bank cards?
The N in NFC is Near. For someone to exploit it they need to be within centimeters of your device. Even if you can do it at 1m, thats close enough that it can just be stolen from you.
Also, your link to rfidgate appears broken.
Stealing the HST should not give the user a false sense of security. Not so dangerous.
Silently exfiltrating the private key (or data for a replay attack), OTOH, would leave the user with a false sense of security. Dangerous.
Wfm. Here’s an archive link.
The setup they have requires a pair of huge antennas, so pulling that off surreptitiously feels unlikely. They also had a controlled lab environment, so who knows how it would work in a less controlled RF space.
Definitely cool research, but this isnt a viable attack vector IMO.