Systems that incorporate a method to allow unlocking using multiple keys don't usually advertise the fact that this is happening. People may even be legally obligated to not tell you.
E2E encryption is not vulnerable to MITM. E2E encryption is vulnerable only to how many keys there are and who has access to them.
What if google told you they also have a key? Does that change the above answer to the question?
Or, as us lowly laypeople call it, lying.
“End-to-end encryption (E2EE) is a method of implementing a secure communication system where only communicating users can participate. No one else, including the system provider, telecom providers, Internet providers or malicious actors, can access the cryptographic keys needed to read or send messages.”
So if you send another set of keys to someone else, it’s obviously not E2E.
This is not enforceable and promises that are not enforceable are usually seen by BigCos of today as optional. My 2c.
> It is possible to set up end to end encryption where two different keys unlock your data. Your key, and a government key. I assume google does this.
Which by definition is wrong (unless the government is a party in the communication you want to E2E-Encrypt).
For example, asking for 10 gallons of soda at a restaurant advertising unlimited refills will not fly, even though virtually everyone will agree on the definition of the term "unlimited". My 2c.
Since you are sending the data to google, isn't google an intended recipient? Google has to comply with a variety of laws, and it is likely that they are doing the best they can under the legal constraints. The law just doesn't allow systems like this.
You're discussing encryption in transit vs encryption at rest in this thread.
they also employ things like exempt cases. for example, Whatsapp advertise E2E... but connect for the first time with a business account to see all the caveats that in plain text just means "meta will sign your messages from this point on with a dozen keys"
The claim is that Google has implemented a security weakness and lied about it in claims to customers and investors.
Show me another company that did this, was exposed, and was not sued.
They have lawyers aplenty, governments would file amicus briefs "explaining" E2EE and so on. Worse case they'll settle for a pittance.
It isnt if the government have asked them to lie.
I guess for consumer use all that stuff is hidden in the T&C legalese which is unreadable for normal people. I know the EU was trying to enforce that there must be a TL;DR in normal language but I haven't seen much effect of that yet.
No, it does not. It means that only endpoints - not intermediaries - handle plaintext. It says nothing about who those endpoints are or who the software is working for.
Key escrow and E2EE are fully compatible.
Unless you’re fine with the escrow agent and anybody they’re willing to share the keys with being a member of your group chat, in which case my original point still stands.
https://engineering.fb.com/2021/09/10/security/whatsapp-e2ee...
The biggest problem remaining to me is that you don't chat alone. You're always chatting with one or more people. Right now there's no way of knowing how they handle their backups and thus the complete history of your chats with them.
It's the same thing as trying to avoid big tech reading your emails by setting up your own mailserver. Technically you can do it but in practice it's pointless because 95% of your emails go to users of Microsoft or Google anyway these days.
> is indistinguishable
Technically correct (with respect to the escrow agent specifically) but rather misleading. With E2EE intermediary nodes serving or routing a request do not have access to it. This protects you against compromise of those systems. That's the point of E2EE - only authorized endpoints have access.
The entire point of key escrow is that the escrow agent is authorized. So, yes, the escrow agent has access to your stuff. That doesn't somehow make it "not E2EE". The point of E2EE is that you don't have to trust the infra. You do of course have to trust anyone who has the keys, which includes any escrow agents.
If we used the definition "only your intended recipients can access the plaintext" ... well let's be clear here, an escrow agent is very much an "intended recipient", so there's no issue.
But lets extrapolate that definition. That would make E2EE a property of the session rather than the implementation. For example if my device is compromised and my (E2EE) chat history leaks suddenly that history would no longer be considered E2EE ... even though the software and protocol haven't changed. It's utterly nonsensical.
So what would be the name for a mechanism where escrow is deliberately not a part of the design and nobody aside from the sender and recipient can access the plaintext data, no 3rd parties whatsoever, as long as those two participants aren’t compromised.
I’m not disagreeing with you but I’ve heard people talk about E2EE while actually thinking it’s more like the above. There is probably a term for truly private communication but I’m sleepy and it eludes me.
However I don't think that's so much a technical mechanism as it is a statement of preference or understanding about who you intend to have access to something.
To that end, you'll need to define "intended recipient" pretty carefully. After all, your intended recipient could take a screenshot and share it. Or there could be someone in a group chat who isn't participating and you forgot was there. Etc.
> There is probably a term for truly private communication
I'd argue that E2EE is "truly private" between the intended recipients, and that understanding who exactly those are is entirely the responsibility of the user.
Of course I recognize that we're talking past each other at that point. Your concern seems to be users not realizing an escrow agent is present. To the extent they might have been deceived about the implementation I'd point out that "snuck in an escrow agent" is just the tip of the security iceberg. They could also have been deceived about the implementation itself. And even if they weren't deceived initially, a binary or web app could be intentionally updated with a malicious version. Does it count as "truly private" if you didn't compile it yourself?
All of these are good points, thanks for taking the time to respond! I think that to a certain degree this means that, for the average layperson and someone with more skills and knowledge, there are still a bunch of challenges and attack vectors to contend with.
It probably involves more of something in the category of OpenPGP (or just Signal, I guess) where you yourselves are in control of the keys, and less of counting on various web apps to do right by the users. That said, E2EE with escrow is still helpful against certain risks and is a net positive, even if I've seen a lot of that misunderstanding about what it actually does.
Anything that you can either audit or compile yourself is generally a good bet. You might add Matrix, XMPP with OMEMO, Briar, and Cwtch to your list.
Proprietary stuff isn't an entirely bad deal though. If you assume they aren't blatantly fraudulent then presumably your data is better protected than it would have been without even an attempt at E2EE.
Same for key escrow schemes. Even if the agent was literally the NSA you'd still most likely be better off than the much more vulnerable alternative. The fewer entities with access and the more deliberate that access is the better.
Wild to see someone on HN even entertain this idea.
Presumably there are a finite number of escrow agents who are known to you. Worrying that they will pass your messages along to others is the same as worrying that the people you're chatting with do the same. It's always on you to assess the trustworthiness of the other parties; key escrow is no exception to that.
To be clear I'm not a fan of large scale key escrow schemes and am not going to willingly use one outside of a corporate setting. But lets have accurate use of terminology while discussing these things.
Surely a company with auditing requirements running their own key escrow would still be considered E2EE? If not E2EE then what would you suppose to call that and where would you draw the line?
This makes absolutely _no sense_. If I do not trust my end user to not propagate the message I send them, then I will not send them that message. There is no need for a third party here to make that mistake. It _is_ that black and white. Adding another end user is compromising your promise on the secure communication you established. There is no workaround to that.
I can imagine a likely objection. "But I'm forced to use this particular agent by [ tech company | employer | government ]!" I don't see how that's any different from needing to communicate with a particular person. If I need to communicate with someone and I don't trust them not to share things then I will (must!) compose my correspondence accordingly.
If the government is forcing this on you, well, what is the alternative? Is point to point encryption somehow better in that scenario? Either way they're getting copies of everything you write assuming that the service you're using abides by the law. With key escrow that snooping is more explicit and there are fewer unknowns for the end user.
The point is that the dictionary definition of E2EE really doesn't matter. Being pedantic about it doesn't help. The only thing that matters is that the vendor describes what they call E2EE.
"a special key" afaik is where instead of using 2 large primes for a public key, it uses 1 large prime and the other is a factor of 2 biggish primes, where 1 of the biggish is known, knowing one of the factors lets you factor any public key with a not insignificant but still more compute than most people have access to.
UK has also invested in some serious compute that would appear dedicated to exactly this task.
basically if you dont have full control over the key generation mechansim and enc/dec mechansim it is relatively trivial for states to backdoor anything they want.
With the present state of politics—lack of both government and corporate ethics, deception, availability of much fake news, etc.—there's no guarantee that you could be certain of the accuracy of any information about this no matter what its source or apparent authenticity.
I'd thus suggest it'd be foolhardy to assume that total privacy is assured on any of these services.
BTW, I don't have need of these E2E services and don't use them, nor would I ever use them intentionally to send encrypted information. That said, occasionally, I'll send a PDF or such to say a relative containing some personal info and to minimize it being skimmed off by all-and-sundry—data brokers, etc. I'll encrypt it, but I always do so on the assumption that government can read it (that's if it's bothered to do so).
Only fools ought to think otherwise. Clearly, those in the know who actually require unbreakable encryption use other systems that are able to be better audited. If I were ever in their position, then I'd still be suspicious and only out of sheer necessity/desperation would I send an absolute minimum of information.
Given the carefully crafted way companies describe their encryption services, it seems more likely than not they have master keys of some sort.
In any case like this, the only thing you could truly trust would be the source code and even then you’d have to be on the lookout for backdoors, which would definitely be beyond my own capability to spot.
In other words, the best bet is to probably only use open source solutions that have been audited and have a good track record, wherever available. Not that there are that many options when it comes to mobile OSes, although at least there are some for file storage and encryption.
We have seen this many times throughout history, where people like academics, researchers, teachers, people of particular faith, etc are targeted and each of them has some sort of “evidence” produced as to some sort of crime they have committed either in the present or past to justify their arrest.
The group who needs it today may be small, but having it on and secure by default for all is a far better protection than any justification that the current need is small.
> encrypts a pdf sent to tech illiterate family members
Not only have you misquoted me, but also you've attempted to distort what I actually said by changing its inference.
1. encrypt data with special key 2. encrypt special key with users key, and 3. encrypt special key with government key
Anyone with the special key can read the data.the user key or the government key can be used to get special key.
This two step process can be done for good or bad purposes. A user can have their key on their device, and a second backup key could be in a usb stick locked in a safe, so if you loose your phone you can get your data back using the second key.