Readit NewsMaybe this differentiation is not popular or well accepted, but it was surely part of my cryptography curriculum and the following exam. I'd rather believe my prof than strangers on the internet.
I've done some development work in Pico-8, and some time ago I wrote a plugin for the Aseprite pixel art editor to convert an arbitrary image into the Pico-8 palette using Floyd-Steinberg dithering[0]
I ran their example image through it, and personally I think the results it gives were the best of the bunch https://imgur.com/a/O6YN8S2
[0] https://github.com/aquova/aseprite-scripts/blob/master/pico-...
Interesting, would you mind elaborating on how you do that? I take it you have your backup key stored on your home server then? What tool do you use to decrypt & parse the backup?
I have an old iPhone that has all my old Signal messages still on it that I wasnt able to move with me when I switched to Android. Is there any way that I can use these new tools to move the old conversations on my iPhone over to my android phone without losing all the new messages that are on my android now?
That is, I want to merge the two histories.
Do not get me wrong. Signal is great software and i'd gladly pay for it. Honestly. But not via this underhanded nonsensical way
> But this new thing is all cross-platform, and in the near future we'll even be making our local backups cross-platform.
This is excellent news! Will there also be official documentation on the backup format, potentially even official tooling like signalbackup-tools[0] to access/parse backups offline? I'm asking because, having used Signal/TextSecure for 10 years now, my backups are worth a lot to me (obviously) and there have been times when I would have liked to mine & process my backed-up data. (Extract media from conversations in an automated manner, build a more elaborate search, …)
My backups have also reached the point where they are so big (15-20 GB) that it's starting to become difficult to conduct a backup each day and sync it successfully before it gets overridden 48h later. So unless I start using the new "cloud backup" feature[1] (which I'm not sure I want to), at some point I will have to archive my existing Signal conversations somewhere and start from scratch (i.e. reset the app). In that case, it would be nice if there was an officially documented way to merge & read new and old backups offline (on my desktop), similar to what [0] provides right now.
[0]: https://github.com/bepaald/signalbackup-tools
[1]: EDIT: Actually, it seems like the new cloud backup feature doesn't support incremental backups, either? https://news.ycombinator.com/item?id=45175387
Also, as someone else noted, the format is indeed incremental. So while we'll still do the thing where we keep the last two backups on disk, because those two backups will share almost all the same media files, the size on disk will be much much smaller. As someone with a 50 GB backup file, this was very much a goal for me :)
[1] https://github.com/signalapp/Signal-Android/blob/main/app/sr...
> Once you’ve enabled secure backups, your device will automatically create a fresh secure backup archive every day, replacing the previous day’s archive.
So IIUC backups will not be incremental and I will have to re-upload my 15 GB backup archive every day? Why is that? What's the security risk here? (Obviously I'm not suggesting encrypting & uploading each message & media file individually but splitting things up into same-sized chunks, like e.g. borgbackup does.)
> At the core of secure backups is a 64-character recovery key that is generated on your device. This key is yours and yours alone; it is never shared with Signal’s servers. This key is different from your Signal PIN, which serves different purposes.
Both recovery key and Signal PIN seem to serve the exact same purpose, though, namely restoring data (conversations, contacts, account, …)? Why not unify them?
> So IIUC backups will not be incremental
Nope! It's very much incremental :) At least the media is. There's one blob of containing all of your messages+metadata which does have to be re-uploaded every night, but for most people that's gonna be somewhere in the low-tens of MB. Your attachments are uploaded incrementally one at a time, typically as they're sent/received, so you usually don't even have to wait to upload them at backup-time.
> Both recovery key and Signal PIN seem to serve the exact same purpose, though, namely restoring data (conversations, contacts, account, …)? Why not unify them?
This was a hard decision and something we went back and forth on. But at the end of the day, we felt the safest thing we could do for now is to use a completely separate strong, random key. We're very aware of all the trade-offs involved, but this is where we landed.
Without backups it makes sense to have a limit, like you said (though I join the person you replied to in wishing there was an option for it yo be more than 30 days), but their point is that once backups contain more than the last 30 days of messages that reason is no longer a blocker.
One caveat is that we don't offer this if you're re-linking an install that already has data but became unlinked. This is because we don't currently handle merging message histories. But if you cleared the data from the secondary install first, it would work. We're thinking of ways to make this smoother!