Probably more relevant today than when the article was first published 7 years ago, this is the guy who went on to make Signal possible in its current form.

If walking away from $850 million feels like penance, Acton has gone further. He has supercharged a small messaging app, Signal, run by a security researcher named Moxie Marlinspike with a mission to put users before profit, giving it $50 million and turning it into a foundation. Now he’s working with the same people who built the opensource encryption protocol that is part of Signal and protects WhatsApp’s 1.5 billion users and that also sits as an option on Facebook Messenger, Microsoft’s Skype and Google’s Allo messenger. Essentially, he’s re-creating WhatsApp in the pure, idealized form it started: free messages and calls, with end-to-end encryption and no obligations to ad platforms.

Acton says that Signal now has unspecified “millions” of users, with a goal to make “private communication accessible and ubiquitous.” While Acton’s $50 million should take it a long way—Signal could afford only five full-time engineers until he came along—the foundation wants to figure out a perpetual business model, whether that means taking corporate donations like Wikipedia or partnering with a larger company, as Firefox has done with Google.

None of the other private messaging services that people like to talk about on Lemmy have a solidly moral billionaire on their side.

I have a little more time now to write more. A Faraday cage needs to fully enclose an object with electrical conductivity in all directions. Solid metal is best, but holes are fine as long as they are substantially smaller than the RF wavelength you’re trying to block.

WiFi has wavelengths between 5 and 13 cm (speed of light divided by frequency). Microwave ovens are also around 12 cm and you can see the small holes in the screen you can see in the glass through the door. “Substantially smaller” than 12 cm, at least by an order of magnitude (10x), but approaching 2 orders (100x), around 1 mm.

5G is a bit all over the place, so let’s stick with wifi.

What matters is the size of the holes in your mesh, the type and thickness of metal, and the quality of the electrical contact across all seams. No gaps bigger than a half millimeter (based on 1/10th the wavelength, or maybe no gaps under 0.05 mm), anywhere. Bags have sewn seams and could spend a little or a lot of effort making it be conductive. Conductivity isn’t a normal sewing consideration and doing it well costs more. Then there’s the access hatch.

In an Anechoic chamber, the door has very good copper (and possibly gold plated, I don’t recall) connections all around a solid door on a big hinge with a big handle that cam-locks everything tightly. Obviously that’s really expensive, but it scales down from there. A good mesh bag folds the lip over on itself, but its still going to be poorly electrically connected at a micro level, especially with dirty durable metals.

You’ll open and close it a lot and it will definitely flex and get dirty, so I expect it to get worse over time.

The seam on a Ramsey box is a U-shaped aluminum channel on the bottom, containing conductive foam covered in a flexible wire mesh layer that gets compressed against the top aluminum edge in the middle. All of the aluminum edges are raw for electrical connectivity, while the outer shell of the aluminum box is coated to make it durable and easy to handle. There’s a decent latch to put a lot of force into holding it closed and compressing that foam tightly. It wears out over time. There’s a lot of work that goes into making that $600 box perform really well.

I’m sure you could find a bag that works half decently, but it will be pretty expensive and it will get worse over time. I’ve handled an evidence bag designed to keep devices isolated in transit. It looked decent, but I didn’t test it. Maybe you can find one of those but I bet it’s not from Bezos.

I kinda disagree with your overall plan being the best response to pervasive corporate and government surveillance, but you should at least be empowered with a scientific basis to evaluate a solution so I hope that helps.

Science Fucking Matters.

Hey now you whippersnapper, just be happy it’s not CVS anymore.

Bags don’t really work, but hard shell boxes do.

Back when I was working with radio devices, we needed real isolation on lab benches, along with the ability to selectively allow RF paths with specific impedance. The gold standard was Ramsey test equipment enclosures, and they really work (although they only provide isolation up to about 90 dB at the frequencies we cared about; for extreme isolation sometimes we had to nest two like Matryoshka dolls).

It doesn’t sound like you need any conducted signal, just isolation, so that will make for a cheaper bulkhead. Here’s the smallest/cheapest Ramsey enclosure. You can probably find used ones on ebay for less, but you may need to hunt for a while.

Another company that makes real enclosures is ETS Lindgren but they’re larger and much more expensive.

If you don’t like the weight/bulk/cost of that solution, then no, you’re not going to find something that actually works.