I don't think so.

Signal might be open source but the servers are still run in the USA and thus are subject to the US "legal system" (which in turn is subject to the mood of its president).

Signal servers only know who talked to whom, but otherwise are physically not able to see even a smattering of the contents of the communication.

Correction: The signal servers don't even have that bit of metadata. See [1], they only store the last time that a user connected to the server.

[1] https://en.wikipedia.org/wiki/Signal_(software)#Servers

> The signal servers don't even have that bit of metadata. See [1], they only store the last time that a user connected to the server.

Note that it's what they claim at least. It's not verifiable client side, and to be honest, it's hard to come up with a scalable protocol where this is the case, but you should still not repeat their claim as a matter of fact while in reality we only have their word that the code actually matches what's deployed. And even if they don't store anything, AWS could still provide interested entities access to the infrastructure to capture what Signal doesn't want to capture. Yes, features like sealed sender are awesome and are an important step, but the service still gets ip addresses, which do provide hints about the sender. Again, likely Signal doesn't store ip addresses but people with access to their infrastructure could.

Furthermore, Signal's encryption doesn't help against people storing all of Signal's traffic and waiting until attacks on crypto algorithms become practical (quantum computers, theoretical progress on attacks). Some secrets become irrelevant with time, others increase in value. The best defense is never having the message leave your country's network in the first place.

And there's the DOS problem. What happens if the american president decides that the EU should be cut off from all US network connections? The EU parliament members can't even organize a good response to this because they use an american service...

Signal app is also canonically distributed by Google Play/Apple Store, which are US entities under US law. When push comes to shove, an app update may get distributed to select individuals that will happily gather and send all their conversation histories and more.

As an EU citizen, I'm half puzzled and half horrified at how happy the EU institutions are to rely on foreign products: especially coming from a country that has a history of being trigger-happy and cutting people off in the name of a "trade war".

I compiled Signal for iOS and monitored the sent data through a proxy. Both behave identical. There could be a hidden switch in the distributed binaries that triggers other behavior, but I really doubt it. For Android, there are reproducible builds so you can actually check the code is the same. For iOS reproducible builds are harder but should still be possible.

Can I verify that the build installed on my Android phone[] is identical to the one that I compiled? For instance, if I mount the device in Linux I can only see /mnt/sdcard, not /, so I can't copy the binaries off.

[] i.e. the build installed on my phone, not the build available no Google's server to download.

What's the alternative? Private closed-source apps like Threema?

This also is not for official communication , it's just for any case where staff would currently use WhatsApp or similar spyware.

I do not think that anyone suggest to use proprietary alternatives. Instead it seems that the posters in this thread would be more happy if the EU was more independent from the US by for example hosting their own signal servers and forking the client.

Matrix, which is already used by the French government.

Under your threat model no internet connected smartphone is safe. Google can just push any arbitrary software to run on your phone and this includes spyware created by governments.

Can one really trust they don't store more if they physicaly have the information at one point in time ? Or possibly their upstream connectivity provider could do that metadata scrapping.

I will link to this each and every time this comes up:

https://signal.org/bigbrother/eastern-virginia-grand-jury/

Signal turned over everything they had on this user (which was two time stamps: user creation and last access), and fought the gag order to be able to publish the subpoena and the response. Signal would have to be pretty stupid to lie to a federal court.

Think what you want, but Signal doesn’t have any metadata to turn over.

If I worked for the intelligence agencies I would be capturing all the info going in and out of the signal servers at the infrastructure level.

Even if I couldn't break the encryption I'd have timing and connectivity data.

So, if I were a user, I would always operate on the assumption that info would leak.

In this threat model, the only defense you would have would be an overlay network resistant to correlation attacks where all nodes are involved in routing traffic (like I2P), or a mixnet like Katzenpost.

Getting people to use Tor for everything is hard enough, good luck getting people to use stuff even more obscure.

And how often where the silenced by US law and weren't even allowed to mention such a thing? We will never know.

Even so, by EU rules, I'd expect them to be required to store the data in the EU.

Do you have an alternative where this isn't true? Honestly the complaints I see about Signal here (servers and being distributed through iOS/Google store) seem extremely low priority and at the point where no true Scotsman exists. Is Signal just not supposed to have servers?

Is there no open source or European alternative?

Just keep relying on some Californian dude that insist i give him my and my friends phone numbers?

And harass me so i give him more info to “personalize my profile” !?

This is the “perfect solution fallacy”; just because Signal doesn’t check all the boxes, doesn’t mean it isn’t an improvement over the existing situation. Secure communications is the immediate goal, nation sovereignty secondary.

Looking at the other comments, the European alternatives don’t look very secure, so it looks like they prioritized security here.

> Looking at the other comments, the European alternatives don’t look very secure, so it looks like they prioritized security here.

In what way are Wire and Matrix not very secure, though?

To be secure step one should always be "Pick a service not controlled by your adversaries' law or intelligence community". Skipping step one has nothing to do with a perfect solution fallacy but is more like "Pissing in your pants for warmth".

A half-broken service would be better than one under US control as the US is the one doing the most snooping on EU. Getting everyone to switch if Signal ever stops being secure would be way harder than to pick a better service now and help secure it.

Matrix would be a better choice for one. Saying EU services isn't secure is hyperbole.

There's Matrix (https://matrix.org/).

How does he harass you?!

- I added a first name to my conversation contacts, but it keeps showing the phone number. In the app and in notifications.

- There is a fixed pop under at the bottom of the screen asking me to confirm my profile name, with “Get Started” or “remind me later” (which is apparently every time i come back to the app), and no “never“ option. I had already put a first name but that’s not good enough. Had to do it again to confirm i don’t want to share a last name with him / them.

- why does he care about the distinction between a “first name” (mandatory) and “Last Name” (optional)

-> Only the user should care about the name.

=> Why should the app / he / them get access to my contacts list to update a contact name? I’m perfectly willing to have duplicate contacts siloed in a “secure messaging app”.

Also, could someone explain why the app need phone numbers ? They only send some initial token over SMS, which can be spoofed.

The phone number deregister flow is such a dark pattern it's incredible. Not something a chat app should ever do to be reputable.

How so?

If you uninstall the app it has a seven day forced delay for releasing your phone number, it isn't disclosed anywhere and the form just silently errors out when seven days haven't passed.

wire: https://github.com/wireapp

session (very bleeding-edge p2p signal fork) https://github.com/Loki-project / https://getsession.org/

There is always boring old XMPP as commonly used for corporate stuff. But then they would have to try to explain to people what a protocol is. That ends up being a problem with IM stuff where people think of the client as the service.

There are, but it should be simple enough for non-techies (politicians) to understand. They could use Threema (Swiss) or Wire, but either-way it's better than plain SMS.

Signal is open source

Well they could use xmpp with omemo.

There is Matrix, which is as far as I know backed by a British company.

There is Threema. Does it have drawbacks?

wire.com is a good option. Open source, chats, calls, video calls, web app, phone app, etc.

wire.com moved HQ to US and “Individual consumers are no longer part of Wire’s strategy.”

I think it is a great decision, but it wil hopefully persuade other people in public bodies to follow suit - such as my friends who work in senior positions in a hospital and use Whatsapp - a practice that started when ransomware took down the NHS e-mail.

I hope nobody tells them that WhatsApp uses the same protocol. The argument for Signal would not be weaker but more complicated.

It's in the article

Main argument is that it's also open source.