Apple Explains How Secure iMessage Is
techcrunch.com
Apple Explains How Secure iMessage Is
1–10 of 126 posts
Re: Apple Explains How Secure iMessage Is
#2And if Apple's servers lie to you and tell you there's a device with a private key they generated?
They may never have your private key, but you are still trusting them to deliver the correct public keys to other users.
Re: Apple Explains How Secure iMessage Is
#3Unless Apple is omitting something or there’s some backdoor tucked into their many-layers-deep encryption (which, while unlikely, isn’t inconceivable) they really can’t read your iMessages without a fairly insane amount of effort.
That is, assuming, that there isn't some code in the app that allows Apple to request that the app send your private key up to the server. It's conceivable that in order to comply with law enforcement, for example, that Apple could just tell the app to send up your private key so that it can decrypt any message they have stored.
There's also no way to verify that your messages have, in fact, been removed from their services.
Re: Apple Explains How Secure iMessage Is
#4They don't have to have your private key to pull off a MITM.
In reality, it is probably secure enough against most adversaries. State level adversaries is a different story.. That you need OTR and key verification in person.
Re: Apple Explains How Secure iMessage Is
#5The way Apple could "read" the messages is by sending a keybag down to the person sending the messages with another public key, one that Apple holds the private key for.
For example if you have 3 devices (iPhone, iPad, MBP) and someone goes to send you a message, they have to re-encrypt the message three times because Apple would have sent them three public keys.
Now if Apple were evil because of a government order, they could send down four public keys, the three ones for the devices you own, and the one public key that Apple has the private key for. At that point once they receive the message they can read it.
Any system that distributes public keys like this can be compromised the same way.
---
The only real way to stop something like this is to make sure that the person you are talking to holds the keys, OTR does this for example by allowing both parties to verify the fingerprint...
Re: Apple Explains How Secure iMessage Is
#6Can't they man in the middle the encryption? If there's a key exchange, how do clients verify the keys they get are legitimate? SSL/TLS uses trusted authorities to verify the public key.
Re: Apple Explains How Secure iMessage Is
#7This is great security for what it is. Probably enough to keep you 98% secure.
Which is still exactly 0% secure as far as I'm concerned.
All in all though - in general - I'll be more than happy to continue using iMessage and feel at peace. As a general rule, however, never send anything electronically that may screw you over later.
Re: Apple Explains How Secure iMessage Is
#8Author 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 doesn't even know if the recipient is mysteriously using a different key that has never been seen before. Sending device does not display any information about how many keys it grabs.
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. You'll never know that you're CCing the FBI device keys on all of your messages.
What's more, is these keys are provided by Apple over TLS without certificate pinning. So now anyone who can mint certificates from a CA trusted by the device can just assume Apple's position. You don't need to hack or legally compel Apple in order to eavesdrop.
If your iDevice is managed by your company IT department, it can be silently fed a certificate without compromising a CA.[1]
Finally, if you did not apply the goto fail update a few days ago, it's trivial to break that TLS channel and also "misconfigure" those keys. That hole has been there since September 19, 2012, by the way.
Basically, iMessage has been securing you against someone who knows how to run wireshark or tcpdump, but not much else.
Re: Apple Explains How Secure iMessage Is
#9The whole document was an interesting read.
http://images.apple.com/iphone/business/docs/iOS_Security_Fe...
Re: Apple Explains How Secure iMessage Is
#10Unless Apple is omitting something or there’s some backdoor tucked into their many-layers-deep encryption (which, while unlikely, isn’t inconceivable) they really can’t read your iMessages without a fairly insane amount of effort. That is, assuming, that there isn't some code in the app that allows Apple to request that the app send your private key up to the server. It's conceivable that in order to comply with law…
> (which, while unlikely, isn’t inconceivable)
Not only do I think it's not unlikely, I actually think it's pretty much a certainty that Apple has a backdoor in their code. After the slides detailing how easy it is for NSA to break into Apple phones I'd be simply shocked if they hadn't inserted such a vulnerability.
Sounds to me like the author is applying a nice coat of white wash.