Because anyone that contacts myusername@mydomain will know they are talking to the same person as a third party that messages that same user, so if those contacts are compromised then a third party could compromise your conversations by correlating them both to you even if the conversation was encrypted. And quantum matters now bc state and capital is hoovering up encrypted data in a strat called Harvest Now Decrypt Later bc they think theyll be able to decrypt it all for cheap in a few short years so its worth holding onto bc storage is cheap. https://en.wikipedia.org/wiki/Harvest_now%2C_decrypt_later https://www.youtube.com/watch?v=-UrdExQW0cs

Ive noticed a couple well upvoted comments relating to the the simplex VC funding so rather than repeat myself I will link the response I wrote already in this comment section https://vegantheoryclub.org/post/916089/1559879

Is there any way to use xmpp such that it is post quantum encrypted at least? Even so it has persistent user ids right? That would still be a simplex advantage

I think you will be interested in the whitepaper, I will append it to the OP https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md I’ve read it and it satisfied me.

please see my comment above and the linked blogpost from evgeny

As an anarchocommmunist I hope they go non profit too, but the protocol is robust and decentralised enough that I’m not worried whatevever the company does it can just be forked. Look at Simple Mobile Tools for andoird, an open source project that sold out to a data harvesting company, within a few months it was forked and now you can get the exact same apps under the name Fossify. And then theres the example of Redhat a forprofit company that “sells linux” by providing techniocal consultation to large businesses. Idk anyone who would say that redhat linux is enshittified bc redhat is forprofit. Evgeny the lead dev has said several times this is the kind of model they want to pursue and they recognise privacy and anonymity is their only selling point, they are into right wing conspiracy theories too so they have an ideological reason not to sell out like that they actually believe in the right to privacy and anonymity. You may be interested in evgenys blog posts about this contention https://simplex.chat/blog/20240516-simplex-redefining-privacy-hard-choices.html

1. If you switch relays you alienate the 99% of people on the central signal network who now have to put in extra work just to talk to you, simplex is decentralised by design anyone can use any relay they choose and the UI is seemlesss bc its handled in the invite link and handshake protocol. 2. Two ways contacts can be compromised, by the attacker simply looking at the phone numbers of you contacts, or if they use usernames instead they can subpoena signal to divulge the phone number associated with the username, from there its trivial to use either leaked phone details or subpoena the phone companies to get your personal details

This is an accurate list of the cons, but my title clearly states I am solely talking about privacy/anonymity goals. Of particular interest was the second bullet there I knew there was a timeout but I didnt think it was that short I will keep that in mind and perhaps suggest it be increased to like at least a couple months. Anyway yes simplex is not feature compatible with signal and matrix. that was not the point of the post. Imo though it IS good enough enough to replace bare bones direct messaging with trusted contacts as I have been using it like that for about 6 months now and it has only gotten more stable since then.

This is kind of black or white thinking to think that its only valuable to use simplex if every one of your contacts uses it. I think of digital privacy like plugging holes in a simking ship to some extent it doesnt matter if you dont get them all if you can bail water fast enough but the more you plug the better. I recommend the arguments in these videos as responses to “i have nothing to hide” https://www.youtube.com/watch?v=Hcqh0ZSza50 https://www.youtube.com/watch?v=0aXIXozAsOE but if everyone you could possible ask to add you on simplex is thinking like this that they don’t want to be lumped in with criminals and what not then this is a disturbing trend that privacy is seen as suspicious

I understand the skepticism, the owner evgeny is a right wing conspiracy person but it has actually already had a security review you might be interested in https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html also because of the decentralised design it is easier to run a simplex relay than a matrix homeserver for example hackliberty.net runs private relays for simplex. All in all I think you’re right to be skeptical of a for profit enterprise but evgeny has said several times they have no intention to profit from user data, they recognise that privacy and anonymity is p much their only selling point so theyve said they want to make profit selling consultations and techniocal expertise to large corporations, kinda like how redhat “sells linux” i guess https://simplex.chat/blog/20240516-simplex-redefining-privacy-hard-choices.html as an anarchocommunist I dont agree with some of the views in this blogpost but I think reading it is a good way to dispell some of the skepticism