Signal's New PIN Feature Worries Cybersecurity Experts (vice.com) 45
Lorenzo Franceschi-Bicchierai, writing for Vice: Ever since NSA leaker Edward Snowden said "use Signal, use Tor," the end-to-end encrypted chat app has been a favorite of people who care about privacy and need a chat and calling app that is hard to spy on. One of the reasons security experts recommended Signal is because the app's developers collected -- and thus retained -- almost no information about its users. This means that, if subpoenaed by law enforcement, Signal would have essentially nothing to turn over. Signal demonstrated this in 2016, when it was subpoenaed by a court in Virginia. But a newly added feature that allows users to recover certain data, such as contacts, profile information, settings, and blocked users, has led some high-profile security experts to criticize the app's developers and threaten to stop using it.
Signal will store that data on servers the company owns, protected by a PIN that the app has initially been asking users to add, and then forced them to. The purpose of using a PIN is, in the near future, to allow Signal users to be identified by a username, as opposed to their phone number, as Signal founder Moxie Marlinspike explained on Twitter (as we've written before, this is a laudable goal; tying Signal to a phone number has its own privacy and security implications). But this also means that unlike in the past, Signal now retains certain user data, something that many cybersecurity and cryptography experts see as too dangerous. Matthew Green, a cryptographer and computer science professor at Johns Hopkins University, said that this was "the wrong decision," and that forcing users to create a PIN and use this feature would force him to stop using the app.
Signal will store that data on servers the company owns, protected by a PIN that the app has initially been asking users to add, and then forced them to. The purpose of using a PIN is, in the near future, to allow Signal users to be identified by a username, as opposed to their phone number, as Signal founder Moxie Marlinspike explained on Twitter (as we've written before, this is a laudable goal; tying Signal to a phone number has its own privacy and security implications). But this also means that unlike in the past, Signal now retains certain user data, something that many cybersecurity and cryptography experts see as too dangerous. Matthew Green, a cryptographer and computer science professor at Johns Hopkins University, said that this was "the wrong decision," and that forcing users to create a PIN and use this feature would force him to stop using the app.
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Came here to recommend Tox if you need SRS BZNS security.
I suspect that ... (Score:3)
A contacts list, profile and blac^H^H^H^Hblock list are things that a user can choose to store locally. Or not at all, in the event their phone is compromised.
Look for an empty canary cage on Marlinspike's curb come next week's trash pickup day.
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Yeah, someone got them by the short and curly. Goddamnit.
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I have to agree. There is no rational explanation for the PIN feature other than they are being forced by the TLAs to collect and retain more information, protecting it only with a 4 digit PIN than can be brute-forced in milliseconds.
I stopped using Signal the instant this PIN thing came out because there really is no other reason for them to have done it other than to comply with secret court orders from the intelligence courts.
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... there really is no other reason for them to have done it other than to comply with secret court orders from the intelligence courts.
No other reason? How about the one on their blog post [signal.org] announcing the feature?
Signal has been adding usability features for a while now (message reactions, device transfer, GIF search, etc.). This is just another thing that people (though not everyone) want. If the purpose is to get more people to adopt e2e encrypted messaging, sometimes convenience features, even if you think they're dumb.
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This is just another thing that people (though not everyone) want.
It doesn't seem to be something that anyone wants, I know a lot of Signal users and every single one of them hates this stupid change. It's something that Signal developers want, and now they're forcing everyone else to use it, whether they want it or not.
Maybe the Signal folks are trying to make themselves attractive to Microsoft for a buyout, showing that they understand Microsoft's way of forcing unwanted things on users.
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For years now the Signal app has required an absolutely ridiculous number of permissions. They come up with daft features to excuse wanting them, but the reality is that if that app did have a backdoor it already had complete access to your phone too.
Then Android changed the way permissions work and suddenly they need to "backup" your data to their server with a PIN that they know most people will set to 1234.
Signal has always been dodgy and we need something better that doesn't try to take over your phone.
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Already Old News (Score:5, Informative)
Moxie Marlinspike
@moxie
Replying to
@matthew_d_green
Based on the feedback we've gotten about PINs, we're working on shipping an option to disable PINs for advanced users who are alright with losing their Signal contacts on reinstall.
Re:Already Old News (Score:4, Insightful)
advanced users who are alright with losing their Signal contacts on reinstall.
How about export to and import from CSV file on their local system? Like every two-bit e-mail client I've ever worked with. Nothing needs to be lost.
Re:Already Old News (Score:4, Insightful)
Damn kids today don't even know what a local file system is!
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kids today don't even know what a local file system is!
Local file systems are simply caching-assisting options for the cloud, where all data is naturally stored. Why, it's almost as if you have something to hide!
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advanced users who are alright with losing their Signal contacts on reinstall.
How about export to and import from CSV file on their local system? Like every two-bit e-mail client I've ever worked with. Nothing needs to be lost.
The kiddies are into JSON now ...
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I like having a copy of all my chat messages with certain friends, but in Signal you have to use some third party hack to decrypt the backup file and liberate the messages.
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I wish I hadn't used all my mod points already, so that I could upvote this VERY SIMPLE suggestion to solve the supposed issue. Many times the simply solution is the best one, and tech companies always forget that in their desire to re-invent the wheel. :)
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Their work making it so that you can store something "in the cloud" but still have an enforcable way to limit the number of attempts at a PIN is quite nice.
But I question the need for that... They say that they want to provide a way to recover your "social graph", i.e. your contact database. However, very few people only want to store their social graph on a single device in the first place, and your social graph is also effectively stored in the social graphs of all of your contacts. These are two oth
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Saw it coming (Score:1)
Signal lost me when they removed the application lock screen and just said, and I quote, "just use the android lock screen". Well sorry there, pork chop, but I have several hundred virtual machines that I have to deal with and passwords sometimes get passed around in your messaging app. I would like to segregate that from the rest of my phone. That's when I knew the end was near. I'm all for a fork that can support multiple servers (user configurable, of course). Or, pretty much any new direction at th
Re:Saw it coming (Score:5, Insightful)
It sounds like their management is moving away from the security conscious community, which as much as this fact makes us sad, we're a niche community and instead trying to go for the mass market, where the money is. The problem is that there's no way to make both the security community and the mass market happy. The mass market wants convenience and damn security for getting in the way of that. They don't want passwords and encryption, they want shoddy thumbprint scans or taking pictures of their face. They don't want their contact information in an encrypted enclave that they have to manage, they want their data 'in the cloud' (not that they have any idea what that actually means), always available waiting for them. It's frustrating for those of us that know what governments and corporations do with our data as we watch the sheep willingly going to get sheered and slaughtered by their shepherds.
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It sounds like their management is moving away from the security conscious community, which as much as this fact makes us sad, we're a niche community and instead trying to go for the mass market, where the money is.
HUH? Really?
Signal is a non-profit organization. It says so right at the bottom of their home page!
Free for Everyone
Signal is an independent nonprofit. We're not tied to any major tech companies, and we can never be acquired by one either. Development is supported by grants and donations from people like you.
© 2013–2020 Signal, a 501c3 nonprofit.
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So? Non-profit means you're not allowed to make a profit. In other words, you have to spend all he money you take in.
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I'm not really interested in arguing the semantics of what "profit" is. My point stands. Notably, you certainly can give money to whomever you want, it just has to be in the form of a salary or fee rather than a dividend.
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You can still pay the CEO millions of dollars as long as you prove that for-profit companies in the same industry pay their CEOs millions of dollar and you can prove that the company has the millions to spare. See where this is going?
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the pin in itself was annoying (Score:2)
I quit signal purely because of the pin. they were obsessed with it, had to be entered so often just to use text SMS, seemed to be at least every day that they wanted to be sure it was me sending. who needs that when you just want to quickly reply to a message?
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Re: the pin in itself was annoying (Score:2)
Or not getting their signal messages because they got a new phone with a new number and thought just reinstalling Signal was enough.
Or someone else getting the messages because they inherited the recycled number and installed signal. That would (maybe) be on the sender for ignoring the safety number changed message.
Or someone else getting the messages because they inherited the recycled number that was never used for signal and installed signal for the first time and the app noticed and switched to signal m
Re: the pin in itself was annoying (Score:2)
Also good points, and just really says the reasons why we're even talking about it. It was awfully convenient to not even have to create an account and just use the phone number. Which means it was always going to lead this way...
I wish Freedom Box was still a thing. But what we need, is an easy to use personal cloud. You could say, use a sample of your contacts to confirm it's you (phone call, in person, etc. it's up to whatever you all setup), But even then, that's also highly exploitable. Security is har
Password manager (Score:5, Informative)
Contact Joined Signal Notification (Score:2, Informative)
When a contact you have joins Signal, you get a notification of this.
That's 100% a violation of the concept of OPSEC. If I join Signal and you have me as a contact it's NONE OF YOUR BUSINESS and a VIOLATION of my OPSEC to "inform" you of what software and services I'm using.
Sorry, I really do like Signal, but that was already strike one -- and a big strike.
This new thing -- requiring a PIN (not a password!) -- and uploading stuff to the cloud -- another big strike.
SIGNAL, take note. One more strike and yo
Re:Contact Joined Signal Notification (Score:5, Informative)
You can actually use a password, just choose an alphanumeric PIN. That's not the default behaviour, however.
KDF (Score:2)
Re: KDF (Score:4, Interesting)
The beauty of these kind of analysis is computers get faster and cryptanalysis finds shortcuts given time.
32 guesses a second might be 64 in 6 months because the GPU got faster. It might be 128 in a few more because boffins found a way to shave a single bit off the execution time. It might be 512 next year because some wily programmer managed to hand-optimize the implementation for a particular GPU. And 2048 the year after when it's built into custom silicon by some TLA whose been archiving Signal data since the feature was added.
Look at 1024-bit DH. It took a while but boffins shaved it down far enough while computers got faster enough and then it was possible to pre-compute all possible combinations for a few hundred dollars of AWS compute time.
Don't underestimate the determination of a well funded adversary when the protection contains a treasure trove of information.
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Traffic latency tracking (Score:2)