Perhaps I'm not hip enough but I'm pretty sure there is nothing more sophisticated than Signal.
BTW, one of Signal's weaknesses is that you MUST use a phone number with it. If you're savvy you realize this can be a Twilio number you control making your account immune from SIM hijacking. However, unless you override a bunch of defaults Signal is not immune to other attack vectors like attempting to unfurl a URL sent in a message -- which can expose your true IP address -- or generate a thumbnail of a video -- which can launch a malware attack -- which is the method of attack alleged to have been used by Saudi intelligence to hijack Jeff Bezos' phone (via an E2E encrypted WhatsApp message no less). A more sophisticated messenger system would turn off lots of "convenience" features by default and let me pick a random username and NOT make me enter a phone number or email address. People who care about security don't need a way to reset their randomly generated 128 character passwords.
This isn't a weakness, it is a tradeoff. You use phone numbers (downside) but the server does not have to store any information about who is talking to who (upside). Other tools reverse this choice and don't use phone numbers but do need to maintain the communication metadata.
When the server knows who you are, the app can use your existing contact list to discover contacts. This means unlike e.g. Telegram, Signal server doesn't store your contact list.
I e.g. constantly see people whose phone number I've already deleted appear on my Telegram contact list "X joined Telegram". Telegram knows I had the number at some point. This would never happen with Signal.
Sure, but you can use VPNs. Or Orchid, which is a multi-hop VPN that routes through multiple VPN providers.
Or you can just use VoIP, which can be done via Tor, as long as you can force TCP mode.
Also, if you're going to stay anonymous, you need something that is extremely hard to misconfigure. I use wireguard on my Android and I've set the VPN to activate automatically, and I only allow connection via VPN, but I'd never imagine any of the apps I'm running are properly anonymized.
Also, since you're apparently working for or affiliated with VPN providers[1], you might want to be more transparent about possible vested interests.
I haven't actually used Orchid, because there's no Linux app. But I did buy some of their Etherium currency. And I recall no money trail. As I recall, I converted well-mixed ~anonymous Bitcoin to plain-vanilla Etherium, and then to Orchid's currency.
But whatever, I'm not going to defend Orchid.
Anyway, I use nested VPN chains. It's like a multihop VPN, except that each hop is a different VPN service, and each of them is leased with a different pool of well-mixed Bitcoin. I do all the Bitcoin mixing via Tor, in Whonix instances. That way, I don't need to trust any of them, only that an adversary won't manage to compromise or coerce all of them. It's the same logic as Tor uses, based on Chaum.
If you want to read more, just search "mirimir" on IVPN's and Restore Privacy's sites. There's also https://github.com/mirimir/vpnchains which is pretty over the top. And I've also played with something like that which routes VPNs via Tor.
When you start to chain VPN nodes you gain latency so you might as well use Tor. These days Tor has enough bandwidth to play 720p video with ease and there's less hassle. Also once you hit three modes you won't really benefit from longer chain so mixing VPN with Tor isn't really beneficial unless you're evading censorship of Tor.
You're wrong about nested VPN chains, however. Depending on geographical distribution, each VPN adds 50-100 msec rtt. And bandwidth doesn't drop that much after the first VPN.
I use both nested VPN chains and Tor to mitigate the risk of Tor circuits being compromised. The lesson of CMU's "relay early" exploit for the FBI was sobering. Given that lesson, only fools use Tor without protection.
Add in some routing trough Tor.
That would be harder to beat by a single law agency.
Particularly harder if the countries implied are not friendly towards each other.
Wait how big is the hash of the phone number?
If it's enough bits (e.g., a full sha hash) then it's not that secure to hash at all. 10^10 or even 10^11 is just 10 or 100 billion. I can easily try all phone numbers until I find the one that matches the hash.
It maybe protects against attacks against lots of people, but it really doesn't protect an individual.
You are correct that using a hash does not protect an individual from other users discovering that they can contact them with Signal, which is to be expected because that's the purpose of this feature. If you suspect that Bob, with phone number +15555551234 has Signal installed, you can verify that by... typing Bob's phone number into your contacts list and installing Signal so you can send messages to Bob.
No matter if your phone number is six digits or sixteen, Signal uses 10 bytes (80 bits) of the hash.
What threat model has a IP be worse to leak than a phone number?
This literally happens with Signal. And it makes sense too, the message that Signal gets telling it someone is now on Signal is presumably the same one letting it know it can use encryption rather than SMS to talk to that person.
If Alice tells Bob a secret via Signal, this means Alice cannot be worse off than if she'd used any other means of telling Bob. Can Bob reveal the secret? Yes. Can he claim Alice told him? Yes. Can he prove it? No.
This is a sharp contrast to something like PGP where Bob can prove Alice sent the message.
The way you normally know a message is from Alice on Signal is that the message was sent using keys only you and Alice share†, and you know you didn't write the message. But a third party has no way to verify that last part. That's the entire trick (in layman's terms).
† Signal and similar systems provide a means to do out-of-band verification that the long term identity key for people you know matches. You probably don't use this with most people, but you can and it's made easy if you want to.
The only way you can know if intelligence obtained is reliable is to actually test it. With systems like PGP you get proof. Did Alice send this message as Bob alleges? Yes, the message includes proof so he was telling us the truth.
With Signal all you have is Bob's word as I described.
Signal can't stop the Secret Police from torturing Bob, but they can ensure they don't have any way to know if he told them the truth. If the Secret Police were rational that's enough reason not to bother torturing Bob. But we can't make them rational, for some people just inflicting pain for no reason is their goal.
1. Friends
2. Family members.
3. Members of a business.
If your life or freedom is on the line because of an association with someone then most systems out there are somewhat dangerous due to the weakness of the endpoints. You would want something like an airgapped computer with on or off line dead drops possibly hidden with stenography.
Well, "the best is the enemy of the good". That's the whole point of risk management. As a practical matter, I do the best that I can manage, or at least, be bothered with ongoingly. If I were as paranoid as you're advocating, I'd be cowering in a bunker. Also, for me there's the fact that I have little left to lose.
That, or blasting your message to a huge number of people, only one or a few of whom actually receive it because it's encrypted and then steganographically hidden in spam. Again, use dummy messages and there's no way to predict anything by divining the ebb and flow of spam volumes.
In contrast to your disinterest in convenience features, Session does have a bunch of things that presumably its principles felt were non-negotiable but clearly harm security. The "Open Groups" feature for example is basically "Eh, this is hard, we give up" for larger groups (500+ people). No end-to-end encryption and you're given either a moderator tool that doesn't work ("Ban" pseudonymous people who can for zero cost just create a new pseudonym) or one that's onerous ("Invite" everybody manually).
Does Signal not ever send messages from, or otherwise use, SMS shortcodes ?
I ask because no twilio number can receive an SMS shortcode (because no twilio number is classified as a "mobile" number).
Genuinely curious.
Not only they do not show anything but use misleading terms in order to confuse the reader.
We do not even know if he was hacked. Right now it is just vague accusations.
I do not care about Saudi Arabia, they are a middle-ages, totalitarian and profoundly sick country. What I care about is misinformation.
(1) https://www.documentcloud.org/documents/6668313-FTI-Report-i...
People that really really need to be sure probably use something super simple like PGP after they take the time to learn how.