As PayPal president David Marcus said: "Bitcoin is good, NFC is bad"
Since I've been working on NFC, I've heard criticism like this but I've never really understood the rationale behind it--especially as NFC might apply to bitcoin and future applications like secure logins using BitID, unlocking physical doors, or replacing loyalty cards at grocery stores.
1. Would it be useful to have a small, battery-less, secure cold wallet that is configured to only sign transactions that move coins to a pre-defined hot wallet?
2. Would it be useful to have a "pocket money" wallet that lets you quickly tap-and-pay at trusted merchants running authenticated point-of-sales hardware (with optional daily spend limits and PIN protection)?
3. Would it be useful to login to your Gmail account with a single tap from your NFC hardware, if HTML5 browsers begin to support the WebNFC API?
4. Would it be useful to create sophisticated multisig wallets such that for larger transactions, the user must tap his phone or computer with a small secure hardware device that stores higher-value private keys?
5. Would it be useful to unlock the doors to your home with the same NFC device that you used to login to your Gmail account, act as a loyalty card at a grocery store, or sign a bitcoin transactions?
