I don't think geuis is saying the actual communication is unreliable, but the actions are. I.e. the NFC part works, but the whole touch to share (say a video or whatever) part has more troubles. Which is a problem even though it is just a failing of handling things hugher up the stack it makes it look like NFC is problematic.

That's a fair point.

The lower level stuff and NDEF format is well standardized. The higher level operations are not nearly as well standardised right now, even more so when you're dealing with large files, which will require a handoff to Bluetooth or WiFi Direct.

In NFC's defense, it's only recently (4.2, Jelly Bean) that Android even supported transferring large files via Bluetooth handoff, so hopefully that stuff will improve with time.

Fair point too. I hope it does improve in time.

> And as for it being unreliable: [citation needed]. I've never had problems sending data to another NFC-enabled device

I've personally never had it work. I tried twice with different two phones (Motorola and Samsung) and while it did recognize it was supposed to do something NFC-esque, the data never transferred. At that point I gave up and just swapped SD-cards and manually copied the data over.

Just my experience but I'm not interested in trying again when there are other methods that I know will transfer data guaranteed to work.

Pretty much any time you have an open port accepting of wireless data, it should be encrypted, especially when that port is on a device with a cpu. In other words, there are no wireless data transmission applications that don't need encryption other than broadcasting.

I can think of one big case: Many NFC tags are used as QR codes. Encrypting this doesn't really get you anything, since it's public information that's being broadcast freely to anyone anyway.

On the flip side, adding the extra hardware to a tag to support encryption has a non-trivial cost. (NFC tags are limited by both storage space and power.) If you're doing mass production of tags, that cost adds up very quickly.

I'd reason that QR codes are a form of broadcasting. encryption can be done on modern chips with specialized hardware at negligible latency costs. chips that have ops for encryption have been around for over a decade now.