Coming from a background of using cryptography regularly (far from an advanced user), this revelation seems... Not surprising. It's practically the equivalent of using SSL for viewing webpages. I say practically because for some mind boggling reason, using standard crypto practices seems to be novel for messaging services on the Internet.
Apple Explains How Secure iMessage Is
41–50 of 126 posts
Re: Apple Explains How Secure iMessage Is
#42Earlier quoted context omitted.
A custom-written third party client could theoretically do this (and mitigate most of the other attacks here). What Apple provides won't help with this though. Think of an SSH client that never verifies host keys and never warns you when they change. That's basically what iMessage is.
Even a custom-written third party client still doesn't eliminate the requirement to trust Apple. They're delivering your closed source operating system, which could very easily include hostile behaviors like key logging and screen recording. At least with iMessage, the entire ecosystem is managed by one company, so you only have to trust one company.
> Even a custom-written third party client still doesn't eliminate the requirement to trust Apple. They're delivering your closed source operating system, which could very easily include hostile behaviors like key logging and screen recording.
It does eliminate the requirement to trust Apple actually. That's the point of (real) end to end encryption. With a custom client, you could use them as a conduit to deliver your message without using any Apple software on either client if you wanted to. As long as the users can verify the keys.
> At least with iMessage, the entire ecosystem is managed by one company, so you only have to trust one company.
I just explained at least 3 different reasons why that is not true. You can fully "trust" Apple and still compromise an iMessage conversation.
Re: Apple Explains How Secure iMessage Is
#43No end-to-end no bueno.
Standard SSL even when done right isn't enough to guard against our current privacy-abusing GO's.
Re: Apple Explains How Secure iMessage Is
#44Apple is able to do this today because instant message services not (yet) covered under CALEA. ( Carrier assistance for Law enforcement agencies.) If CALEA is updated to include instant messaging services, Apple would be legally obligated to have a method of intercepting these messages, possibly with a separate public key as discussed in other comments.
Re: Apple Explains How Secure iMessage Is
#45As mentioned in other comments, you have to trust Apple to hand you the correct public keys. They could easily MITM you and decrypt the messages on the server if they misrepresent the other party's public key. Additionally, the iMessages you send are signed by your private key, which is probably not something you want.
> iMessages you send are signed by your private key, which is probably not something you want. Why not?
Because they can be used against you and you won't be able to deny the message has originated from you, which is a desirable security/privacy property in a messaging app setting. OTR, and mpOTR[1] in particular, try hard to remove non-repudiability from messages.
Re: Apple Explains How Secure iMessage Is
#46The 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 that IBM/Lenovo/etc. have put on laptops?
Also:
> The 88-by-88-pixel, 500-ppi raster scan is temporarily stored in encrypted memory within the Secure Enclave while being vectorized for analysis, and then it’s discarded after.
I wonder what kind of neat stuff people could come up with if we had raw access to that kind of sensor data.
Re: Apple Explains How Secure iMessage Is
#47Earlier quoted context omitted.
That would only be the case if someone does it by logging in to your iCloud account, which applies to none of these attack scenarios. Even then, it only notifies the owner of that account, not the party who is sending messages to unverified keys. If you're spoofing the keyserver, it's invisible to Apple. If you're the FBI and serving a warrant on Apple, Apple does not send the message telling you that "FBI's MacBook…
Pardon my ignorance not being a security expert, but given that all endpoints here (software and hardware) are Apple-controlled, just how trivial is spoofing a keyserver? Genuinely curious.
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Re: Apple Explains How Secure iMessage Is
#48This 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.
If you see security as boolean, you're going to have a rough time...
Re: Apple Explains How Secure iMessage Is
#49Earlier quoted context omitted.
> (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.
After reading a post by a Google engineer on this issue, I'm going to err on the side of believing that Google, Apple, and others aren't actually actively inserting back doors into their code. https://plus.google.com/108799184931623330498/posts/SfYy8xbD...
By all accounts, these secret court orders often come with gagging clauses - which would likely extend to even gagging one employee from telling another. For all I know the guy next to me could be under a secret court order forcing him to insert backdoors.
Of course, as there's no way to disprove this hypothesis, and there's no proof of it, you can still err any way you like :)
Re: Apple Explains How Secure iMessage Is
#50Earlier quoted context omitted.
That would only be the case if someone does it by logging in to your iCloud account, which applies to none of these attack scenarios. Even then, it only notifies the owner of that account, not the party who is sending messages to unverified keys. If you're spoofing the keyserver, it's invisible to Apple. If you're the FBI and serving a warrant on Apple, Apple does not send the message telling you that "FBI's MacBook…
Pardon my ignorance not being a security expert, but given that all endpoints here (software and hardware) are Apple-controlled, just how trivial is spoofing a keyserver? Genuinely curious.
Assuming (perhaps incorrectly) that Apple does not use certificate pinning for their iMessage servers, and the adversary controls a trusted CA (likely for secretive government agencies), and the adversary controls a router somewhere between the device and Apple (also likely for government agencies), it's very trivial.
It's a simple matter of redirecting traffic using something like iptables.