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Comment by mirimir | Hacker News Reader

Well, but ...

> But anyone testing the beta who links their iPhone to iCloud and wants the same level of privacy Signal has always offered should consider an extra step, too: Disabling a setting that uploads a call’s metadata to Apple. The beta upgrade to Signal will use CallKit, Apple’s framework for allowing VoIP calls like Signal’s, to be integrated more completely into the calling functionality of the phone. But that also means calls will be recorded in the iPhone’s call log and, for iCloud users, shared with Apple’s server. “iOS treats CallKit calls like any other call, however that also means some information will be synced to iCloud if enabled,” Open Whisper Systems warns. “This information includes who you called and how long you talked.”

https://www.wired.com/2017/02/encryption-app-signal-enables-...

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> This information includes who you called and how long you talked.

Given the recent shift from data to metadata protection, which is the only justification for messaging centralization, this vulnerability effectively reduces security to almost zero.

At the same time, metadata collection via a gag-ordered pen register on Signal is still possible in principle, this would just make it slurpable by existing prism type tools potentially already operating on iCloud. Those truly concerned with metadata should go to Tor, and not use signal, independent of this feature.

I expect this is another case of UX/Security tradeoffs considerately made by OWS. Having native OS integration is nice, and probably the right answer for most users.

How feasible is call setup correlation when there are 10000 calls per minute going through the servers?

Signal allows my (non-technical) friends and family to help raise the bar while providing a chat client that offers basic calling features.

Signal isn't about being perfect (it's already made tons of concessions that make it useless to anyone "serious" about privacy). Instead, it helps raise the bar against bulk collections.

Except the parent is right, if you don't have metadata protection by default, then it is no different than running something that's federated but secures it's transport or secures its payload end to end.

Bulk collection concerns the envelope, knowing who you spoke to and how long for is _exactly_ the kind of information NSA was tracking 5 years ago. Content was never the issue, content can be encrypted by default with non-centralised systems. What's the point of a centralised system now, that was its only justification.

If you have a Trojan on your phone that steals all your call info, remove the Trojan instead of not calling people. If signal isn't seamless and doesn't provide a good experience, nobody will use it, making it useless. If you don't want Apple to track your calls, get an Android phone or disable iCloud. What are you doing with iCloud if you're privacy-conscious, anyway?

But is that information not encrypted in iCloud by Apply? I thought they were encrypting everything by now, and if so, as long as you use an iPhone you are probably already trusting Apple to keep things safe, so in theory, it's still secure.

And yet Signal has not and does not allow retaining messages when moving to a new device (essentially, migrating messages to a new device) because it explicitly marks its data with the do not backup attribute to avoid leaking data. I find this sort of design decisions unappealing. If it put up a message on first launch and allowed the user to decide that, or even kept the current design on data backup as the default with a hidden setting to allow it, the app would be more useful.

As it stands, Signal is good for voice calls where one doesn't usually have a need to retain content of the conversation. For text messages, it becomes useless after sometime (when the user changes devices).

You can actually do a plaintext import / export of all of your chat histories from the menu in the conversations screen (at least in Android.) It won't use OS level backup/restore, but I feel like that would've taken flak on HN anyways :)

If you're not syncing to iCloud, do you still need to disable CallKit to keep your current levels of privacy?

At a glance, it looks like no. It appears that if you have iCloud Drive enabled, Apple will store call history there for the purposes of syncing across devices. If iCloud Drive is disabled, it appears the call logs never leave the device.

http://www.macworld.com/article/3142400/data-center-cloud/ap...

Thanks!

Why not disable that syncing by default?

I imagine the value for a Signal user to have his calls logged in iCloud is quite low, if not zero.

Also, it's quite frustrating how Apple doesn't allow granular control of what gets synced to the iCloud. It's all or nothing. There's no good reason to do it this way, other than them not wanting to do the work required to make that change.

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