The new "Security through trust in big corp" model.
Apple Explains How Secure iMessage Is
91–100 of 126 posts
Re: Apple Explains How Secure iMessage Is
#92Earlier quoted context omitted.
>Apple wants to read your messages? They drop one of their public keys in the list. Apple gets a warrant? They drop the FBI's key in the list. If they were doing this, it would come out real quick. You'd just send a message to a different account you control then see how many keys you're getting/encrypted messages you're sending. Someone like Applebaum, who knows he's under surveillance and has the crypto/networking…
GP's point is sound: the weakness in public key crypto is key exchange. Unless you can independently verify that the keys you're getting from Apple belong to the intended recipient, the system doesn't work. You don't even have to add a key to the pool, you simply replace a key in the pool with a key generated by Apple, and when the message arrives on the server, it's decrypted and sent to anyone at all, and then re-e…
If you have access to the private keys, which I'm assuming as I'm not talking about users trusting the system but rather researches identifying malicious use, then it's trivially easy to verify that the public keys being used are those, and only those, that correspond to the correct devices.
It's not a good system, but it's also not one that is impervious to detection of malicious activity.
Re: Apple Explains How Secure iMessage Is
#93Apple could mitigate most of the security concerns listed in this thread by listing the trusted devices which you're encrypting against. This solves the "extra encryption key" angle. You'd still have to trust your recipient to be just as mindful of this as you to prevent the vulnerability in the other direction though.
> by listing the trusted devices which you're encrypting against
More precisely, on a user device: list the contact devices and key fingerprints. Adding a contact's device: on first exchange show fingerprint and ask for trust then pin the pubkey. Warn should the key change. What remains is for parties to exchange fingerprints in a peer to peer side channel (possibly even physically via bluetooth/qr-code).
Re: Apple Explains How Secure iMessage Is
#94Author isn't very clever about crypto attacks. Sending device grabs all of the recipients public keys (as well as all of their own keys for other devices, which allows the conversation to be replicated on all of their own devices as well) hosted by Apple. Sending device has no way to verify those keys belong to the intended recipient . User has no way to verify which, or how many devices they are sending to. User doe…
I found a comment on this blog [1] by someone claiming to have reverse engineered the iMessage protocol. [2]
In his comment, he says: "OS X 10.9 (and probably also iOS 7) does certificate pinning for the push connection, I don't know about the directory lookup."
[1] http://blog.cryptographyengineering.com/2013/06/can-apple-re...
[2] https://github.com/meeee/pushproxy/blob/master/doc/apple-pus...
Re: Apple Explains How Secure iMessage Is
#95Earlier quoted context omitted.
Lawful intercept isn't evil.
When there are secret courts and laws, it is evil. It is indistinguishable from the surveillance state.
Hardly. I think people's concern is with the use of warrants that apply to a massive range of people to justify (legally) data collection en masse without being backed by intelligence and probabal cause. Declaring that all warrants for communications material are evil because a certain subset are evil does not work to improve our situation at all; it is a tabloid worthy knee jerk reaction, and while such populism is common here, it is not constructive.
Re: Apple Explains How Secure iMessage Is
#96The whole document was an interesting read. http://images.apple.com/iphone/business/docs/iOS_Security_Fe...
Agreed. I found this bit about Touch ID interesting: > With one finger enrolled, the chance of a random match with someone else is 1 in 50,000. However, Touch ID allows only five unsuccessful fingerprint match attempts [...] I assumed it was more accurate than 1 in 50,000. Then again I don't know what a normal fingerprint sensor is capable of. Does anyone know the accurate of the sensor in the new S5, or the sensors…
As I understand it, most fingerprint scanners can only distinguish between on the order of tens of thousands of fingerprints. 50,000 is higher than other numbers I've heard for fingerprint scanners (30-40k).
Re: Apple Explains How Secure iMessage Is
#97What would be more interesting to me would be a comparison between the security of the iMessage protocol and similar competing facilities like SMS and Google Hangouts.
Re: Apple Explains How Secure iMessage Is
#98Earlier quoted context omitted.
At a certain point people who are worried about the 'much else' part have to take personal responsibility for their paranoia. Apple cannot prove they aren't reading your iMessages. Maybe they are beaming them into deep space because they want to help aliens come get you. Who knows? It's hard to disprove. Anyone who reaches that level of paranoia should not be using these services.
Apple cannot prove they aren't reading your iMessages. Sure they could. They could change the protocol and UI so that the users could verify and pin keys, and they could publish the iMessage source[1] to allow people to check it and compile it themselves. Whether they should be expected to do these things is a different issue, but they could. [1] not necessarily under a liberal license - for example, PGP was propriet…
They could publish the source, but how do you know that source is running on your iPhone?
Re: Apple Explains How Secure iMessage Is
#99Earlier quoted context omitted.
Apple cannot prove they aren't reading your iMessages. Sure they could. They could change the protocol and UI so that the users could verify and pin keys, and they could publish the iMessage source[1] to allow people to check it and compile it themselves. Whether they should be expected to do these things is a different issue, but they could. [1] not necessarily under a liberal license - for example, PGP was propriet…
They could publish the source, but how do you know that source is running on your iPhone?
Compile it yourself or get some trusted party to it for you, and sideload it. "But you can't sideload iOS apps!" Well, then we're back to what Apple could do.
Re: Apple Explains How Secure iMessage Is
#100Everyone needs to start caring a lot more about verification and authenticity of keys (even public keys). iMessage anchors all trust in Apple Inc. with no means to verify that you're public key has not been swapped.
If you can't verify and pin keys, then assume there is no encryption.