Technology Preview: Signal Private Group System • Hacker News Board

Re: Technology Preview: Signal Private Group System

#41

Post by lorenzhs » Mon, Dec 09, 2019, 9:20 PM UTC

myu701 wrote: post #5

noja wrote: post #3

Earlier quoted context omitted.

> This is either a reason you love Signal (raises hand) or can't stand Signal. Eh? Why either or? (and why are there people who can't stand it?)

I love Signal, and upsell it whenever I can. Signal has its ideosyncratic parts, some of which are being worked on, others not so much. Some of the more visible ones are IMO: Signal forces users to use phone numbers; some people don't like this because they want to use multiple ephemeral usernames so they can be 'Joe' to friends, 'kleptoclown' to their github group, 'dungeonmaster42' to their DND group, 'joesolutione…

> ”Signal cannot have multiple mobile clients, only one mobile client and a single desktop version”

This is wrong. You could always have multiple desktop clients. You can also add iPads as linked clients now. Personally, I have two desktops and an iPad linked to Signal.

WhatsApp doesn’t support linked devices at all, the web client connects through your phone. Signals linked devices function independently, you can power off your phone and they’ll still work.

Re: Technology Preview: Signal Private Group System

#42

Post by yabadabadoes » Mon, Dec 09, 2019, 9:22 PM UTC

jacobolus wrote: post #40

yabadabadoes wrote: post #31

Earlier quoted context omitted.

Personally, I'm happy to lose the data. I found it odd that with both phones and the SIM on the desk in front of me, I couldn't figure out how/if I could vouch for my key changing in any way. Needing to say I have a new phone just trust me largely defeats the purpose.

I’m talking about transferring archival data from one phone I own to a different phone I own. This is different from whether other users are told that my security keys just changed.

Right, I think there's a partial process for what you want and not for informing of key change and I find that backwards AFA security.

Re: Technology Preview: Signal Private Group System

#43

Post by mderazon » Mon, Dec 09, 2019, 9:31 PM UTC

JoshTriplett wrote: post #19

tptacek wrote: post #2

Again, in the theme of "features every group messaging system had already, but Signal didn't, because they hadn't figured out a way to implement it without turning Signal's central servers into a database of who's talking to who about what". Signal didn't even have user profiles until recently, for the same reason. Here, they've slightly expanded the state of the art in MAC-based anonymous credentials to accomplish t…

Honestly, the one and only feature I'm missing in Signal that would let me use it and recommend it to everyone without reservations (rather than exclusively for ephemeral-only communication) is the ability to keep identity and full message history when moving to a new device. Today, on iOS, you can't move your Signal history to a new device, and on Android you can only do so by manually making an encrypted backup fil…

I actually going in the other direction with Signal

I turned on timer (1 week) for all of my conversation.

Nothing stays more than a week and I do not keep any backup.

It's not for security or privacy reasons. I feel like I don't need a full history of all my conversations with everyone from the beginning of time.

This fits more to the real life model of having a conversation with someone. I don't record my conversations with people so why do I need to do it in chat apps?

My Whatsapp is the same. Don't need all the massive amount of chat history...

Re: Technology Preview: Signal Private Group System

#44

Post by rpdillon » Mon, Dec 09, 2019, 9:34 PM UTC

juped wrote: post #22

tptacek wrote: post #20

Earlier quoted context omitted.

Because we're talking about group messaging here.

Why would group Signal messages (a drop-in replacement for group texts) be compared to Slack?

I recently was selecting a messaging platform for my family, and we evaluated both Signal and Slack, and went with Slack. My wife did the same with her family, and went with Signal. From this, I gather they overlap in some features enough to compete for some use cases.

Re: Technology Preview: Signal Private Group System

#45

Post by yarrel » Mon, Dec 09, 2019, 9:34 PM UTC

noja wrote: post #3

tptacek wrote: post #2

Again, in the theme of "features every group messaging system had already, but Signal didn't, because they hadn't figured out a way to implement it without turning Signal's central servers into a database of who's talking to who about what". Signal didn't even have user profiles until recently, for the same reason. Here, they've slightly expanded the state of the art in MAC-based anonymous credentials to accomplish t…

> This is either a reason you love Signal (raises hand) or can't stand Signal. Eh? Why either or? (and why are there people who can't stand it?)

It's a great piece of software, so people love it.

But the sometimes uncritical love people have for it doesn't help when it has issues.

The main categories of people I've encountered who aren't absolute Signal fans are:

* People who don't want to give out their phone number to random men.

* People who weren't impressed by Signal's security issues coming up at the same time that it was being pushed as the replacement for GPG.

Re: Technology Preview: Signal Private Group System

#46

Post by m-p-3 » Mon, Dec 09, 2019, 9:36 PM UTC

mderazon wrote: post #43

JoshTriplett wrote: post #19

Earlier quoted context omitted.

Honestly, the one and only feature I'm missing in Signal that would let me use it and recommend it to everyone without reservations (rather than exclusively for ephemeral-only communication) is the ability to keep identity and full message history when moving to a new device. Today, on iOS, you can't move your Signal history to a new device, and on Android you can only do so by manually making an encrypted backup fil…

I actually going in the other direction with Signal I turned on timer (1 week) for all of my conversation. Nothing stays more than a week and I do not keep any backup. It's not for security or privacy reasons. I feel like I don't need a full history of all my conversations with everyone from the beginning of time. This fits more to the real life model of having a conversation with someone. I don't record my conversat…

I'm with you on that. Maybe it's just me, but I believe that a communication system (be Signal or email) is not designed for long term storage, it's just not efficient to keep structured data and not made for that purpose.

If a fragment of a conversation is useful, I'd store it somewhere else safe just in case (Password Manager, as a secure note).

Re: Technology Preview: Signal Private Group System

#47

Post by JoshTriplett » Mon, Dec 09, 2019, 9:37 PM UTC

mderazon wrote: post #43

JoshTriplett wrote: post #19

Earlier quoted context omitted.

Honestly, the one and only feature I'm missing in Signal that would let me use it and recommend it to everyone without reservations (rather than exclusively for ephemeral-only communication) is the ability to keep identity and full message history when moving to a new device. Today, on iOS, you can't move your Signal history to a new device, and on Android you can only do so by manually making an encrypted backup fil…

I actually going in the other direction with Signal I turned on timer (1 week) for all of my conversation. Nothing stays more than a week and I do not keep any backup. It's not for security or privacy reasons. I feel like I don't need a full history of all my conversations with everyone from the beginning of time. This fits more to the real life model of having a conversation with someone. I don't record my conversat…

Interesting that that model works for you, but that doesn't mean it works for everyone.

Persistent history that lasts many times longer than the lifetime of any one device is a required feature to fully replace chat apps that have such history.

Re: Technology Preview: Signal Private Group System

#48

Post by BLKNSLVR » Mon, Dec 09, 2019, 9:38 PM UTC

JoshTriplett wrote: post #19

tptacek wrote: post #2

Again, in the theme of "features every group messaging system had already, but Signal didn't, because they hadn't figured out a way to implement it without turning Signal's central servers into a database of who's talking to who about what". Signal didn't even have user profiles until recently, for the same reason. Here, they've slightly expanded the state of the art in MAC-based anonymous credentials to accomplish t…

Honestly, the one and only feature I'm missing in Signal that would let me use it and recommend it to everyone without reservations (rather than exclusively for ephemeral-only communication) is the ability to keep identity and full message history when moving to a new device. Today, on iOS, you can't move your Signal history to a new device, and on Android you can only do so by manually making an encrypted backup fil…

I think I'm an exception in this instance, but I don't understand what value there is in message history. How often do you find yourself reminiscing by going back through a messaging log?

If there are photos that should be kept then there are other ways to back them up. Is there valuable context in the conversation that was had around the delivery of the photo?

Are messages backed up and restorable for other messaging systems, and have you ever needed to go through a restore process to look back through a conversation?

If it's for the purposes of software project development team discussion and history needs to be kept for legal reasons then I think Signal is intentionally not aiming at that demographic.

I get that there are special moments in life but, for me, the textual conversations around them are very secondary to the moments themselves. But then, in discussions I've had with other people, my opinion seems to be the exception.

Re: Technology Preview: Signal Private Group System

#49

Post by eitland » Mon, Dec 09, 2019, 9:40 PM UTC

tptacek wrote: post #29

jacobolus wrote: post #26

Earlier quoted context omitted.

My biggest annoyance with Signal is that getting a new phone ends up wiping out all conversation history with apparently no way to transfer it. This loss of user data is not advertised well enough up front, and leaves users feeling tricked. In many contexts loss of user data is an even bigger sin than weak security.

What's ironic here is that in the adversarial setting the application is designed for, unexpected retention of user data (on end-user devices) is a sin.

For some of us data loss is often a bigger threat than unexpected retention.

I like Signal and it always makes me happy to see more people showing up there, but for now certain group chats will stay on other messaging services.

Re: Technology Preview: Signal Private Group System

#50

Post by eximius » Mon, Dec 09, 2019, 9:47 PM UTC

tptacek wrote: post #37

SheinhardtWigCo wrote: post #33

Earlier quoted context omitted.

To verify the claim that my group message content is protected, I can examine the Signal client. I don’t have to trust the server operator whatsoever; I can independently confirm there is no way for them to see the content of my messages. In contrast, I cannot verify this new claim that my group memberships are protected. I have to trust them. I think you are basically saying: ‘well, they built all this crypto that i…

No, what I'm saying is that without the cryptographic protections, a messaging provider can't claim not to be logging, because their serverside logic requires the log. Prior to doing this cryptographic work, Signal simply went without having these features at all.

You're both right. The other poster's claim is that we cannot verify the code running on the server. They could support this new scheme AND just store every thing in plain text. We can only verify the interface is the same (because that's what we're using).

But you're also right it would be a long con to go without these features for so long, develop state of the art cryptography to add them securely and privately, then not use that.