[HN Gopher] New 'negative light' technology hides data transfers...
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New 'negative light' technology hides data transfers in plain sight
Author : wjSgoWPm5bWAhXB
Score : 39 points
Date : 2026-03-11 20:46 UTC (2 days ago)
(HTM) web link (www.unsw.edu.au)
(TXT) w3m dump (www.unsw.edu.au)
| charcircuit wrote:
| It seems simpler to use a secure radio protocol instead of
| relying on security by obscurity for communication.
| StevenWaterman wrote:
| A covert signal is still beneficial even if the signal is
| secure. The existence of the signal is valuable metadata.
|
| For a contrived example, imagine I'm in a warzone:
|
| - Secure = Enemies can't read my messages. Good. But they can
| still triangulate my position.
|
| - Covert = Enemies don't know I exist
| pinkmuffinere wrote:
| +1. As another example see
| https://en.wikipedia.org/wiki/Numbers_station -- people can't
| decipher the messages, but they strongly suspect something
| spy-y is going on. If they couldn't even detect it, there
| would be no suspicion.
|
| Also hi StevenWaterman, I recognize you from previous
| comments! I think this is the first time that's happened to
| me on HN
| applfanboysbgon wrote:
| Another example: in some regimes merely using Tor is illegal,
| or say in the US using it is enough to justify a search
| warrant for probable cause, with no evidence of any actual
| wrongdoing. The EU Chat Control lobby is also trying very
| hard to criminalize encryption. The simple act of trying to
| communicate privately is taken as indicative of criminal
| wrongdoing in the modern world. Being able to communicate
| without adversarial parties knowing you're communicating is a
| boon.
| jkhdigital wrote:
| Secure channels can still be jammed. Undetectability is a
| fundamentally different goal than secrecy.
| bob1029 wrote:
| DSSS is sort of both security and obscurity at the same time.
| The very act of spreading your spectrum out via a secret key
| also has the effect of reducing the amplitude of your
| transmission, ideally below the noise floor. A receiver on the
| other side wouldn't see anything except noise unless they had
| the same key.
| hmmokidk wrote:
| I am sure you could encrypt the warmth message somehow.
| esseph wrote:
| Unless your adversary is scanning for RF emissions, which is
| getting more and more common.
| thatcherc wrote:
| Link to the paper:
| https://www.nature.com/articles/s41377-025-02119-y
|
| From the abstract:
|
| > Here, we demonstrate a covert communications method in which
| photon emission is rapidly electrically modulated both above and
| below the level of a passive blackbody at the emitter
| temperature. The time-averaged emission can be designed to be
| identical to the thermal background, realizing communications
| with zero optical signature for detectors with bandwidth lower
| than the modulation frequency
|
| It sounds like maybe they're modulating the emissivity of a diode
| up and down so that over time, its IR spectrum looks like black
| body radiation. Only someone looking at the intensity of the
| thermal radiation coming from the diode at really fast timescales
| (kilohertz or megahertz) would notice that there was a signal
| being transmitted.
| TheOtherHobbes wrote:
| Maybe I'm missing something, but this reads like a complicated
| way to say "We made an IR diode that gets cold as well as hot."
| thewanderer1983 wrote:
| Yep.
| scottyah wrote:
| It's impressive how this article made this sound like a
| breakthrough, didn't even mention the entire historied field of
| steganography once.
| jkhdigital wrote:
| The paper itself mentions steganography in the second sentence
| at least.
| dustfinger wrote:
| > Only a receiver with the right equipment can pick up the hidden
| message.
|
| So all an eavesdropper has to do is setup the right equipment
| then? I guess it is only invisible until the technology becomes
| more widely available.
| behehebd wrote:
| As invisible as radio signals then.
| Retr0id wrote:
| > We do have encryption methods, but at the same time we're
| always having to create new encryption methodologies when bad
| actors find new decryption strategies.
|
| > But if someone doesn't even know the data is being transferred,
| then it's really very hard for them to hack into it. If you can
| send information secretly then it definitely helps to prevent it
| being acquired by people you don't want to access it.
|
| Very strange framing. Symmetric cryptography has been
| "unhackable" for a while now, for all intents and purposes. The
| real advantage is surely that nobody notices you're transmitting
| data at all?
| nine_k wrote:
| The cypher may be prefectly impenetrable, but the software
| running on the transmitter or receiver may be more brittle. You
| cannot attack what you don't even know exists nearby.
| Retr0id wrote:
| A secure cipher is indistinguishable from random data, you
| can't infer what software is on either end just by
| eavesdropping.
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(page generated 2026-03-13 23:00 UTC)