Privacy @lemmy.ml HiddenLayer555 @lemmy.ml 1mo ago

How secure is sending files over Bluetooth?

If I pair my Android phone and my laptop, I can share files over Bluetooth from the phone to the laptop. I've started finding this a really convenient method for me to send files to a Linux laptop without needing to install a separate app on either the phone or my laptop. Especially when I'm away from my home network (I use SFTP at home).

How secure is this? Is there encryption by default and could someone else nearby with a receiver potentially decode the file you're sending?

29 comments

It’s actually entirely horse shit.

Only the very newest products that are on the latest standard are secure.

It all look secure and sounds secure and feels secure with all the encryption….

But about 2 years ago there was a downgrade attack that was proven to affect basically everything.

Bluetooth security might as well be a flashing neon sign of your data.

Now it’s not quite that simple and some people have updated their devices etc……

But almost nobody actually has done that because Bluetooth devices are “fire and forget”

I mean when’s the last time you updated the firmware on your headphones or keyboard?

Mostly “never”
- You have to be pretty close to sniff Bluetooth data though. So fine at home, less so in a busy public space. (The chances of someone there trying to hack your Bluetooth is still astranomically small)
  
  Low odds because “you aren’t worth the effort required” agreed.
  
  But the distance officially is like 33 feet to 300 feet depending on the adapter.
Heads up, I know you said "without additional apps," but check out KDEconnect, it's pretty sweet.
- Also LocalSend
  
  Pairdrop.net is better I would say
https://localsend.org/
- https://pairdrop.net/
  
  No, thanks:
  
  It uses a WebRTC peer-to-peer connection. WebRTC needs a signaling server that is only used to establish a connection. The server is not involved in the file transfer.
  
  If your devices are paired and behind a NAT, the PairDrop TURN Server is used to route your files and messages.
It is encrypted, but the security of the encryption varies between implementations (some have been found to generate keys insecurely or screw up session management, etc). For most modern devices it's decent, as long as you're not actively targeted by some kind of intel agency
How can you send files over bluetooth when you are not home? You are confusing it with something else. Bluetooth has a 10 meter radius. Also, it is not secure at all, if you send important files and suspect that someone might be eavesdropping within 10 meters, don't use it
- ... I assume they have both the phone and laptop with them when they are away from home?
I've been using Flying Carpet, and it works pretty well. You can read about the encryption decisions further down the ReadMe.

https://github.com/spieglt/FlyingCarpet?tab=readme-ov-file

It utilizes the LocalOnlyHotspot API, and the data is encrypted in transit (and any potential hacker would have to be on the WPA2-protected network that's generated, anyway). I recommend reading more about it yourself and not just taking my word for it.
It's alright but if you really want it to be private, specially when in a public space, you should use a cable. It would be faster too.

29 comments