Automated Symbolic Verification of Telegram's MTProto 2.0

to achieve that is left as an exercise to the reader, see 1password, restic, borg, and many others that store with zero trust yet are accessible by multiple devices, or even multiple parties) (side note: claims that multi-device messaging can't be done because E2E are incorrect, e.g iMessage does it, by having each message encrypted multiple times, once for each device of the recipient account) > So while the tech might be solid, the keys are still out there. They can be leaked. They can be subpoenaed IIRC it was advertised that Telegram keys (presumably for data at rest) are stored split upon two (or more) different servers residing in different jurisdictions so that subpoenas would only get at most half of it or require international cooperation. But then if you enter that ground, Telegram just as much as Signal could be court-pressured to produce a client that wiretaps data right where it's decrypted and phone home, so E2E only saves you if you audit every client version that this does not happen. As always in matters of security, first step is to define your threat model, and who you want to secure against, as there's no such thing as perfect security. > No analysis needed. I would definitely like to see one done by an unbiased party, because everything I can find are blanket gut-feeling statements without reference. EDIT: just found this, which is a bit light but still something: https://restoreprivacy.com/secure-encrypted-messaging-apps/t... and this: https://arxiv.org/pdf/2012.03141v1.pdf

warrant - and has had some high-profile exploits over the years, but the current iteration of its cryptographic protocol has been proved secure [1] (disclaimer: the paper claiming so came out within the last month, and I haven't found any discussion or review). All of the client apps are open source. The server is not, but if the clients are properly encrypting messages, that shouldn't be a security concern (To my knowledge. I am not a cryptographer). Discord is community-oriented. It's primarily based around "guilds" (commonly referred to as servers) that function similar to Slack workspaces. A robust role-based permission systems has made it pretty much the de facto standard for large communities wanting a real-time discussion platform (think subreddits, Discourse forums, etc). They have some top-of-the-line engineers who sometimes publish cool blog posts about their ridiculously performant clients [2]. Nonetheless, nothing is encrypted, they aren't open-source, and they have an unclear monetization model [3]. Signal is designed, intentionally or not, as a SMS replacement. It's build around one on one and small group messages. Their encryption is strong, independently verified, and enabled by default (Signal falls back to SMS for others who don't use it). Think iMessage, but open-source and secure. You'll see HN complain about its UI from time to time, but really, it's quite good. It's also extremely easy to convince friends and family to switch to. Matrix aims to be to real time chat what email is for asynchronous communication. Rather than a service, it's a standard, which means you'll see swaths of clients strewn about GitHub and other websites, the most feature complete of which is Element [4]. In practice (or for the time being), Matrix is just better IRC. VoIP and video calls are somewhat hodge-poged into the spec, but do work well, and encryption by default has been rolling out over the past year. Direct messaging, group chats, and communities are also all supported, although the latter suffers from the IRC-like limitation of only one "channel" per server. I know nothing about Threema or Viber, sorry. [1]: https://arxiv.org/abs/2012.03141 [2]: https://blog.discord.com/why-discord-is-switching-from-go-to... [3]: https://cadence.moe/blog/2020-06-06-why-you-shouldnt-trust-d... [4]: https://element.io/