Signal is secure, as proven by hackers

If Signal is secure really depends on your threat model.<p>While they never classified them as data breaches, they had all the numbers in their system extracted number of times.<p>If someone was using a real phone number, even if Signal was secure — just knowing the number alone would give an attacker addition information. When Moxie was in charge, he repeatedly refused to allow new users to signup without phone, even though in there numerous ways this could have been done and are being done by their competition.<p>Lastly, all three Signal board members have held the top leadership role in past year, which is highly unusual, in fact, never heard of anything like it.

I don&#x27;t see it mentioned in the article (though I might have missed it), but:<p>&gt; As such, the cybercriminals managed to pull off the attack by impersonating the victim of the attack for roughly 13 hours.<p>All the contacts of that victim would have received a warning that the victim had changed their encryption keys (WhatsApp has that warning too, but unlike Signal it&#x27;s disabled by default), and IIRC, that warning shows up before you try to send a message. Even if they&#x27;re not the kind of people who checks whether the encryption keys match (it&#x27;s very easy to do if you&#x27;re meeting in person, but not many people do), that warning can be enough to alert the contact that something odd is going on.

&quot;secure&quot; is not a binary state.<p>Title is low-brow and weak.<p>&quot;secure from a small group of specific hackers&quot; is not as catchy though.

Whatever the security of Signal is, all my trust into any service ends when it requires from me personally identifiable information, which could be easely replaced by other methods (I am system software developer for ~31 years, don&#x27;t even try to feed me with bs).<p>And as such, Signal&#x2F;Telegram&#x2F;Whatever that requires me to enter phone number, has zero trust from me. I don&#x27;t care who analyzed the protocols security, what the safety measures are, what cipher algorithms you use, how many hackers tried to break in and failed, what other PR&#x2F;SEO methods you use.<p>Just the fact, that you require information that is so deeply PII as phone number is a reason that overrides everything else. From my standpoint, software that requires that, is honeypot.<p>(btw, this is my personal opinion, you don&#x27;t have to agree - I can (from any device, without giving any PII, now or 20 years in past) login into IRC network (vpn&#x2F;... is outside this topic) and use asymmetric cryptography (with exchanging public key safely by some other method, stenography anyone?) to chat completely secure. I can send email (with exchanging public key safely by some other method, stenography anyone?) and communicate completely secure. I can use Counterstrike chat on random server to do the same. So what does the Signal does for me in terms of safety of exchanged information? Show me a nicer UI so I can use graphic smileys?)

Signal contact ≠ Phone contact address book.<p>By disabling Signal’s access to phone contact address book, Signal server would not have a hash value of each and every (10,000+) phone numbers in your phone’s contact address book. This disabling comes with small costs of:<p>- being notified that someone in your phone’s contact address book has just recently signed up with Signal. (Pop your finger from your mouth)<p>- of ease of NEW lookups of a friend using your expansive 10,000+ contact address book that your phone maintains. Ummm, your focus is the secured messaging with just the targeted friends of yours, and not one of your crazed ex-girlfriend nor deranged boss.<p>You still have a separate but more secured form of a contact address book maintained by Signal (and yes, remote Signal server has a hash value of these smaller but limited set of Signal-capable phone numbers of your friends).<p>The key thing is no one else can see the content of your messaging … over Signal … except who you converse with … by Signal app, unless your phone ends up in the hand of a digital forensic guy before you did the steps of doing “Settings-&gt;Account-&gt;Delete Account”.<p>On a separate topic, you should refrain from using Avatar and discourage your friends from doing so. That’s an out-of-band lookup that is available for nation-state or hacker to profile further with.

You can&#x27;t prove that something is secure by &quot;hackers&quot;. You can only prove it&#x27;s not secure.

If only Signal found a way to keep the desktop app linked for more than 30 days. There have been a series of FRs that constantly get ignored and &quot;you&#x27;re using it wrong&quot; from the developers.<p>Thankfully the one friend that was using Signal finally gave up on it since everybody else was always missing his messages, so I no longer have to re-link every single computer every time I use the app. (with a 30 day expiry and 3 computers, it meant virtually 100% of the time I tried to use the desktop app I had to relink to my phone).

&gt; And although the attack was formally a success, there is no reason to get scared and stop using Signal.<p>This conclusion — “no reason to…” — sounds strange and premature. Such attacks may not get older messages, but contacts of the person whose phone number has been used can still message the new device, which the hacker would get and could launch further attacks on the contacts. Since practically almost nobody verifies “safety number” changes, the contacts of the phone number that has been taken over may not realize they’re chatting with someone else. Isn’t that reason enough to be scared? This problem exists for any app that relies on an external identifier, especially one like a phone number that’s easier to take over (including through SIM jacking).<p>Signal may be secure for specific definitions, but your contacts may not be safe with such takeovers.

&gt; By using end-to-end encryption, user messages are stored only on their devices, not on Signal’s servers or anywhere else.<p>How do we know with certainty that the messages are not stored anywhere else? Don&#x27;t they go through servers to get to the end user?

&quot;And second, the numbers themselves aren’t stored there in plain text, but rather in the form of a hash code.&quot;<p>Very strange. There is no additional security by hashing phone numbers. Not that I trust anything form this source but anyway.

Does anyone know why Signal has decided to not let people sign up without a phone number?<p>That would avoid any such vector relating to SMS, albeit at the expense of making it more difficult to recover an account from a new device.

Signal alternatives that are open source and cross-platform (at least Android and iOS compatibility):<p><a href="https:&#x2F;&#x2F;jami.net&#x2F;" rel="nofollow">https:&#x2F;&#x2F;jami.net&#x2F;</a><p><a href="https:&#x2F;&#x2F;berty.tech&#x2F;" rel="nofollow">https:&#x2F;&#x2F;berty.tech&#x2F;</a><p><a href="https:&#x2F;&#x2F;cwtch.im&#x2F;" rel="nofollow">https:&#x2F;&#x2F;cwtch.im&#x2F;</a><p><a href="https:&#x2F;&#x2F;simplex.chat&#x2F;" rel="nofollow">https:&#x2F;&#x2F;simplex.chat&#x2F;</a><p><a href="https:&#x2F;&#x2F;status.im&#x2F;" rel="nofollow">https:&#x2F;&#x2F;status.im&#x2F;</a>

Signal imo should secure its desktop apps better. The sqlite database of messages is stored right next to the json file containing the encryption key. Admittedly you would have to get access to the hard drive before reading it and I&#x27;m not sure other messaging apps do any better, but still an attack surface left open. This also means you can&#x27;t trust disappearing messages. It&#x27;s better than not having the feature. But it&#x27;s trivial to setup an auto-archiving script on all incoming messages.

I would like to have a deep analysis about Telegram. The founder Durov always says like Telegram is secure and it encrypt the message while it&#x27;s not.

Here&#x27;s one major problem with Signal - you cannot delete contacts.<p>Following scenario:<p>1) X communicates with Y using Signal trying to hide from Iranian police<p>2) Y is getting arrested and who ever is found to have his phone number is getting in to trouble as well<p>3) X deletes Y from its contacts<p>4) Y stays in X&#x27;s contacts on Signal no matter what<p>now what should X do? delete Signal? theoretically the police could reinstall it and see who you had in your contacts.<p>There have been several issues opened for this problem on GitHub for years. They all get closed by their bot after couple of weeks.<p>I have several ghost numbers and even ghost user names on my Signal clients. Super annoying and cluttering my list of contacts. For me Signal is just one option to avoid WhatsApp. But boy do I prefer Telegram ...

How comes the linux desktop client of signal is such a bloated mess, which can&#x27;t be used standalone but only via phone app?

The weird part about this - why does Signal let anybody access the same account with just a SMS verification? I would think it would be better to send the verification message to be added to an account through their Signal account. Telegram does this already.

&gt;As such, the cybercriminals managed to pull off the attack by impersonating the victim of the attack for roughly 13 hours. If Registration Lock had been enabled, they could not have logged in to the app knowing only the phone number and verification code.<p>and if Signal did not require a phone number, this wouldn&#x27;t have happened at all

As I am fond of saying: identity is <i>the</i> issue with end to end encrypted messaging. So this is interesting in that it is a direct attack on the weakness of using access to a phone number as proof of identity.

Something I’ve been hearing about on podcasts is how the Jan 6 insurrection trials has a bunch of Signal messages in evidence. Does anyone know how these were obtained?

Misleading title. There was no &quot;hack of Signal&quot; but the authentication services, instead.

This old article only proves how vulnerable Signal is by relying on the security (or lack thereof) of other 3rd party service providers.<p>The phone number requirement should be removed if Signal wants to be taken seriously. Maybe the next hit might affect more users than 1900 people.

Imo Signal never actually transition from a protocol for secure messaging into an actual secure messaging app.

Surviving one attack != secure

I just want to backup my Signal online a rar and a pass, easy to restore in another phone or manually, without the rest of the joke steps.<p>Using PII which is also a joke, “secure” implies “private” also, else it is just “encrypted”. When someone knocks on your door in a Ukrainian or African or … village and asks for the pass, you give it.<p>The non private money sending also a joke of privacy. A monero-like solution would be good enough.<p>Less features than whatsup or viber or telegram so why bother? It is really easy to copy each others’ features, but each app’s developers think that they are the smartest people in the room.