Fibre-optic cables could be used to spy on people a kilometre away | Hacker News Reader

Fibre-optic cables could be used to spy on people a kilometre away

arxiv.org

96 pointssizzle22 comments

I think this is the OP: https://arxiv.org/abs/2207.05267

Note the headline may confuse: the reference to 1 Km relates to the fiber run between the eavesdropping equipment and the target. It's only picking up sound in the same room, not 1 Km away.

Ok, let's change to that URL because the submitted URL is hardwalled: https://www.newscientist.com/article/2330763-fibre-optic-cab....

Thanks!

hardwalled? you mean paywalled?

I’d guess hard, as opposed to soft (dismissible/based on number of articles read), paywall.

I assume a hardwall is not merely circumvented by css/js shenanigans.

I just mean a paywall without workarounds (as the sibling comments have pointed out).

Paywalls with workarounds are ok on HN, paywalls with no workaround are not.

https://news.ycombinator.com/newsfaq.html

https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...

https://news.ycombinator.com/item?id=10178989

Not in the article, but the implication from this study is that it is surprisingly easy to "bug" a room using purely opt-mechanical devices and keep all detectable electronics far removed.

For example, single strand of very thin glass fiber that can't easily be detected by an eye and receiver several rooms away or even hundreds of meters away.

To protect against laying out thin fiber inside concrete or even under the paint beforehand would make eavesdropping undetectable. No wonder they watch every phase of embassy construction so carefully.

The paper describes how to mitigate eavesdropping:

> Changing the fiber adapter connecting to the modem from a flat PC end face to an angled APC end face can reduce the echo, which is also a practical method to avoid the risk of being eavesdropped.

only see none APC on cheap china drop cables and fast splice connectors around here. none APC tends to be higher loss.

Is this the same as distributed acoustic sensing using fiber optics cables? If so, the leading company in the world right now is these guys if anyone is interested: https://terra15.com.au/

I am sure it is no longer a big deal but alot of high security perimeter sensors used this technology.

https://www.researchgate.net/publication/358578918_Epicenter...

https://www.researchgate.net/publication/357008566_Time_shif...

p.s.

Just skimmed the papers. Based on the first, I think you need the location of the target (which could be moving) for this mechanism to work. (The target is the 'epicenter').

Wondering if having a voice signature of the target would allow for fishing for the target's voice if location is not precisely known.

p.s.s. the papers are authored by scientist named in the OP.

Coming soon: Meta Fiber

is the tail fiber bare or in standard shielding (rubber sheath?) for this setup?

either way, this is clever and fun.

Seems to be a paywalled article, but presumably this is under very ideal conditions; everything is microphonic to some extent, but anything that acts as a sufficiently sensitive microphone is going to pick up tons of ambient noise too.

https://archive.ph/eDhcu

I tried that too but it’s still truncated.

https://arxiv.org/abs/2207.05267

Assuming everyone here is familiar with the movie "The Conversation".

Could this be considered the modern-day or updated version of the stingray?

The Stingray works by tricking mobile phones into communicating with it over mobile phone protocols, while this is more akin to a laser microphone that records audio using light waves, so they're not very parallel technologically, except for both being surveillance methods.

Completely unrelated, nothing to do with gsm band rf

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