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Comment by espeed | Hacker News Reader

The Signal protocol (https://en.wikipedia.org/wiki/Signal_Protocol) has been vetted, and the code is online available to be audited:

- Signal code: https://github.com/whispersystems/

Telegram has had known flaws, which have been discussed in part here:

- Telegram protocol defeated. Authors are going to modify crypto-algorithm https://news.ycombinator.com/item?id=6948742

- A Crypto Challenge For The Telegram Developers https://news.ycombinator.com/item?id=6936539

- Telegram (initial discussion) https://news.ycombinator.com/item?id=6913456

https://hn.algolia.com/?query=telegram&sort=byPopularity&pre...

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How much of that Telegram info applies to anything in the last 2 years or so?

They still haven't open sourced the server afaik. The thing that is a problem with Telegram is that they market on their security, but it's not secure by default, or on group chats. Moreover, it stores chat histories, and if you add someone to a group chat they get access to the historical data. A lot of folks use it without thinking about this, or understanding the implications.

The protocol is secure, but we have no idea if the implementations are secure (except Signal itself), because we can't audit them.

In fact, Facebook Messenger's implementation of Signal has very questionable security right out of the box, because if one party "reports" an encrypted conversation, the whole thing is decrypted and sent to facebook support staff.

So someone reporting a message to Facebook would be the equivalent of that person (either Alice or Bob) reporting and sending the content of the other person's encrypted conversation to a third party.

The Signal Protocol provides end-to-end encryption so you don't have to trust the intermediate parties/servers involved in relaying the message (e.g. you don't have to trust Facebook's servers), and to protect against the other person reporting and revealing your conversation to someone else, the Signal Protocol provides message repudiation [1], which effectively gives the sender plausible deniability because the receiving party cannot prove to a third party that a message came from you.

[1] https://en.wikipedia.org/wiki/Signal_Protocol#Properties

Yes, my concern is that this functionality is baked into the client and is at a high risk of being executable remotely.

It's not just about the protocol though, it's the whole stack, and the OSes that it runs on are frequently not secure. Also, the Signal app on Google Play requires your phone number and a Twilio API call to function. No thanks.

That's something we can't do anything about though.

We can't do anything about the phone number requirement?

The phone number is not required as per the Signal protocol -- it's an implementation detail -- another token could be used. At this time, phone number verification is used in the initial authentication flow to protect against someone else spoofing your phone number and pretending to be you.

See https://github.com/WhisperSystems/Signal-Android/issues/1181

Actually magic link sent to your email would be MUCH better. Also central authority but Gmail >>> any telecom

It also doesn't have to be a central authority, since "anyone" (meaning: anyone who can afford to operate a mailserver, which is actually a surprisingly-high number) can be such an authority for one's own mail.

Practically nobody is running own mail server these days. Email is extremely centralized

one single actor < a few large actors you can choose from < lots of actors to choose from < medium size organizations can and do often run their own < individuals can ran their own (Email Is Here) < individuals commonly run their own

Let's not make the perfect the enemy of the good.

I still run my own for personal email (postfix + dovecot). Runs off a Linode VM atm and has no problem getting through to Gmail, Hotmail etc. users.

"Most people don't know rocket science" "Actually I know some rocket science!"

Just because practically nobody is doesn't mean practically nobody can't, which was my point.

That's true, but not a given.

I used to run my own but I can't find anyone to relay the mail anymore.

> Also central authority but Gmail >>> any telecom

There's few of the big corps I trust as little as Google.

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