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There is zero control over what public keys get handed over to your phone to encrypt an iMessage with. For all we know, whenever you want to send a message to $

by pilif 12y ago

There is zero control over what public keys get handed over to your phone to encrypt an iMessage with. For all we know, whenever you want to send a message to $USER, your phone gets a public key for $USERs iPhone, her iPad and the NSA master key. Tim Cook can state that they can't decrypt the message all he wants, but as long as there's no control over what public keys we encrypt the message with, the statement that Apple or the NSA can't read the messages is a half-truth at best. Don't use iMessage for anything you wouldn't be using email for. Assume every message you send over iMessage to be public. >If the government laid a subpoena to get iMessages, we can’t provide it. It’s encrypted and we don’t have a key. And so it’s sort of — the door is closed. But the government can (and probably has) force you to have the phones send a copy of every message to some government server encrypted with the government's public key. They don't need to subpoena messages - they already got them all.

jacquesm 12y ago
> Assume every message you send over iMessage to be public. You should assume any message that you send over the internet to be public unless you're a crypto expert. And if you want to go one step further then you should probably consider anything you type into a computer to be public.
mehrdada 12y ago
"as long as there's no control over what public keys we encrypt the message with, the statement that Apple or the NSA can't read the messages is a half-truth at best." This. That said, it is reasonable to believe the way iMessage is architected would likely make mass surveillance harder in general, just like widespread use of SSL does, so it is not entirely useless either. The bigger problem IMO is that they then upload the message database unencrypted (from server's standpoint) to iCloud in the backup process (which is admittedly optional, but effectively on for most users). That, of course, is easily readable, as the celebrity hack shows.
- dogecoinbase 12y ago
  make mass surveillance harder in general More specifically, it makes it so that Apple is not forced to conduct mass surveillance by giving up everything when they receive a legal wiretap order, in the vein of Lavabit. If you see someone else running a message system that has no way for the cops to read it, that should be a sign that it's insecure -- not technologically, but architecturally.
  - aianus 12y ago
    > If you see someone else running a message system that has no way for the cops to read it, that should be a sign that it's insecure -- not technologically, but architecturally. What's that supposed to mean? What about OTR or TextSecure or PGP over email?
    - dogecoinbase 12y ago
      someone else running
  - ejr 12y ago
    I'm unclear as to what you mean by that last sentence. If someone is running a message system that is distributed and keys to encrypt and decrypt are store locally, not on the server, then why wouldn't it be secure? The message system may be anything as simple as an addressing system Ex: Email, which is run by any number of providers, however if an email client is configured to use PGP and access is via POP/IMAP and not webmail, it's still secure as far as we know. A message system that may not be email, but still doesn't store keys on the server, still provides no way for cops to read it. Except perhaps to see some message was sent, not what the message was.
jamesk_au 12y ago
The fact that Apple could in the future modify their system to permit them to read iMessages (e.g. by interposing themselves between sender and receiver using fake public keys) is not really a fair basis for alleging that Tim Cook or anyone else is telling "half-truths" in respect of what Apple is currently doing. He has said they are not reading them and that, at present, they cannot read them. I'm not aware of any basis for impugning his credibility in that respect. But it remains the case that anyone seriously concerned about security should continue to guard against that possibility in the future.
simonh 12y ago
He didn't make a statement that Apple or the NSA can't read your messages. He said that Apple can't read your messages. However since you are so concerned about half truths, if you're going to criticise someone's statements, it would be nice if you'd address what they actually are saying. It's entirely possible that the NSA has hacked Apple, or that an Apple employee has been subverted by the NSA and inserted a back door into the encryption system. Tim Cook wouldn't know about that and can't give assurances of that kind, and isn't trying to. All he can do is state what Apple as a company intends and can do acting according to it's policies. So yes it's entirely possible Apple or the NSA has back door keys to iMessage. Tim Cook is now publicly on record saying that Apple don't. That's not a 'half truth at best'. It's either true or it's a lie. I'm not telling you to believe him or not, but historically these things have a way of coming to light eventually, one way or another.
- danieldk 12y ago
  The half-truth is here: If the government laid a subpoena to get iMessages, we can’t provide it. It’s encrypted and we don’t have a key. It's encrypted and they don't have the key, but since the user does not have any control over the public keys being added, they could add a trusted public key and get it anyway. So they can actually provide messages if they really wanted to. I don't believe they really want to. But the thing we should've learnt from last year's revelations is (1) that companies can be forced to do so anyway via secret courts; and (2) the NSA is willing to make a 'technical solution' otherwise. So, Tim Cook is not being completely honest here. Apart from what hardware can do, the only way to trust such an application is if you had the source code, the source code of the operating system and the source code to firmware blobs, and some way to prove that everything was compiled from public source code without modifications. Since that is not going to happen, iMessage should be considered as secure as unencrypted e-mail when it comes to governments. Of course, it does provide more protection than e-mail against less equipped actors.
  - simonh 12y ago
    They can't create trusted public keys after the fact, they'd have to already have them. So there's no half truth. Either they currently create and store such public keys or they don't. Tim Cooke is saying they don't. That statement can't be half true. It's either true or false.
fpgeek 12y ago
It's even worse that that. As of about a year ago, iMessage didn't do any certificate pinning: http://blog.quarkslab.com/imessage-privacy.html http://blog.quarkslab.com/imessage-privacy.html Unless that's been fixed (I haven't come across any evidence one way or the other), you're not just worrying about Apple and the NSA: Your iMessages are vulnerable to anyone who can forge a certificate and MITM your connection to Apple's servers. I'd say that's a reasonably high bar except for one thing: I believe it covers the vast majority of corporate iPhones used on company-internal networks.
- cbr 12y ago
  Certificate pinning usually (ex: Chrome) is implemented with an exception to allow a company administrator to install a new root CA cert on the device and MITM connections. Does iMessage not allow this?
  - acchow 12y ago
    This Chrome behavior surprised me so I checked the source. Indeed, you are correct. Pin checking is short-circuited if the cert is signed by a root. ` if (!is_issued_by_known_root || !HasPublicKeyPins(host, sni_available)) { return true; } ` https://code.google.com/p/chromium/codesearch#chromium/src/net/http/transport_security_state.cc&q=kPreloadedSTS&sq=package:chromium&type=cs&l=137 https://code.google.com/p/chromium/codesearch#chromium/src/n...
    - lawnchair_larry 12y ago
      Well I'll be damned. Those sneaky bastards. Thanks for pointing this out.
imaginenore 12y ago
Even if you could set your own keys, there's no guarantee their infrastructure doesn't leak them to NSA. And considering Snowden's revelations, it's more likely than not.
rayiner 12y ago
Your presumption is that iMessage encryption is useless if the NSA can still read the messages. Speaking for myself, I don't care if the NSA can read my messages. My biggest concern is keeping my private data protected from for-profit corporations like Apple and Google.
- lawnchair_larry 12y ago
  Crypto it's useless in the sense that the trust model is broken. The point of crypto is to trust math, not people. Apple can read iMessages too, but it's a safe bet that they don't.
jcromartie 12y ago
Even if you could provide a key to iOS, would you trust that it's actually using it as you'd expect it to?
serve_yay 12y ago
I don't really disagree with the reasoning, I just disagree with how Apple only is the recipient of such scrutiny. Same deal with payments stuff. And the reason basically boils down to, they have fancy ads and their products look really nice so they must be lying to us.

by pilif 12y ago

jacquesm 12y ago

> Assume every message you send over iMessage to be public. You should assume any message that you send over the internet to be public unless you're a crypto expert. And if you want to go one step further then you should probably consider anything you type into a computer to be public.

mehrdada 12y ago

"as long as there's no control over what public keys we encrypt the message with, the statement that Apple or the NSA can't read the messages is a half-truth at best." This. That said, it is reasonable to believe the way iMessage is architected would likely make mass surveillance harder in general, just like widespread use of SSL does, so it is not entirely useless either. The bigger problem IMO is that they then upload the message database unencrypted (from server's standpoint) to iCloud in the backup process (which is admittedly optional, but effectively on for most users). That, of course, is easily readable, as the celebrity hack shows.

dogecoinbase 12y ago
make mass surveillance harder in general More specifically, it makes it so that Apple is not forced to conduct mass surveillance by giving up everything when they receive a legal wiretap order, in the vein of Lavabit. If you see someone else running a message system that has no way for the cops to read it, that should be a sign that it's insecure -- not technologically, but architecturally.
- aianus 12y ago
  > If you see someone else running a message system that has no way for the cops to read it, that should be a sign that it's insecure -- not technologically, but architecturally. What's that supposed to mean? What about OTR or TextSecure or PGP over email?
  - dogecoinbase 12y ago
    someone else running
- ejr 12y ago
  I'm unclear as to what you mean by that last sentence. If someone is running a message system that is distributed and keys to encrypt and decrypt are store locally, not on the server, then why wouldn't it be secure? The message system may be anything as simple as an addressing system Ex: Email, which is run by any number of providers, however if an email client is configured to use PGP and access is via POP/IMAP and not webmail, it's still secure as far as we know. A message system that may not be email, but still doesn't store keys on the server, still provides no way for cops to read it. Except perhaps to see some message was sent, not what the message was.

jamesk_au 12y ago

The fact that Apple could in the future modify their system to permit them to read iMessages (e.g. by interposing themselves between sender and receiver using fake public keys) is not really a fair basis for alleging that Tim Cook or anyone else is telling "half-truths" in respect of what Apple is currently doing. He has said they are not reading them and that, at present, they cannot read them. I'm not aware of any basis for impugning his credibility in that respect. But it remains the case that anyone seriously concerned about security should continue to guard against that possibility in the future.

simonh 12y ago

He didn't make a statement that Apple or the NSA can't read your messages. He said that Apple can't read your messages. However since you are so concerned about half truths, if you're going to criticise someone's statements, it would be nice if you'd address what they actually are saying. It's entirely possible that the NSA has hacked Apple, or that an Apple employee has been subverted by the NSA and inserted a back door into the encryption system. Tim Cook wouldn't know about that and can't give assurances of that kind, and isn't trying to. All he can do is state what Apple as a company intends and can do acting according to it's policies. So yes it's entirely possible Apple or the NSA has back door keys to iMessage. Tim Cook is now publicly on record saying that Apple don't. That's not a 'half truth at best'. It's either true or it's a lie. I'm not telling you to believe him or not, but historically these things have a way of coming to light eventually, one way or another.

danieldk 12y ago
The half-truth is here: If the government laid a subpoena to get iMessages, we can’t provide it. It’s encrypted and we don’t have a key. It's encrypted and they don't have the key, but since the user does not have any control over the public keys being added, they could add a trusted public key and get it anyway. So they can actually provide messages if they really wanted to. I don't believe they really want to. But the thing we should've learnt from last year's revelations is (1) that companies can be forced to do so anyway via secret courts; and (2) the NSA is willing to make a 'technical solution' otherwise. So, Tim Cook is not being completely honest here. Apart from what hardware can do, the only way to trust such an application is if you had the source code, the source code of the operating system and the source code to firmware blobs, and some way to prove that everything was compiled from public source code without modifications. Since that is not going to happen, iMessage should be considered as secure as unencrypted e-mail when it comes to governments. Of course, it does provide more protection than e-mail against less equipped actors.
- simonh 12y ago
  They can't create trusted public keys after the fact, they'd have to already have them. So there's no half truth. Either they currently create and store such public keys or they don't. Tim Cooke is saying they don't. That statement can't be half true. It's either true or false.

fpgeek 12y ago

It's even worse that that. As of about a year ago, iMessage didn't do any certificate pinning: http://blog.quarkslab.com/imessage-privacy.html http://blog.quarkslab.com/imessage-privacy.html Unless that's been fixed (I haven't come across any evidence one way or the other), you're not just worrying about Apple and the NSA: Your iMessages are vulnerable to anyone who can forge a certificate and MITM your connection to Apple's servers. I'd say that's a reasonably high bar except for one thing: I believe it covers the vast majority of corporate iPhones used on company-internal networks.

cbr 12y ago
Certificate pinning usually (ex: Chrome) is implemented with an exception to allow a company administrator to install a new root CA cert on the device and MITM connections. Does iMessage not allow this?
- acchow 12y ago
  This Chrome behavior surprised me so I checked the source. Indeed, you are correct. Pin checking is short-circuited if the cert is signed by a root. ` if (!is_issued_by_known_root || !HasPublicKeyPins(host, sni_available)) { return true; } ` https://code.google.com/p/chromium/codesearch#chromium/src/net/http/transport_security_state.cc&q=kPreloadedSTS&sq=package:chromium&type=cs&l=137 https://code.google.com/p/chromium/codesearch#chromium/src/n...
  - lawnchair_larry 12y ago
    Well I'll be damned. Those sneaky bastards. Thanks for pointing this out.

imaginenore 12y ago

Even if you could set your own keys, there's no guarantee their infrastructure doesn't leak them to NSA. And considering Snowden's revelations, it's more likely than not.

rayiner 12y ago

Your presumption is that iMessage encryption is useless if the NSA can still read the messages. Speaking for myself, I don't care if the NSA can read my messages. My biggest concern is keeping my private data protected from for-profit corporations like Apple and Google.

lawnchair_larry 12y ago
Crypto it's useless in the sense that the trust model is broken. The point of crypto is to trust math, not people. Apple can read iMessages too, but it's a safe bet that they don't.

jcromartie 12y ago

Even if you could provide a key to iOS, would you trust that it's actually using it as you'd expect it to?

serve_yay 12y ago

I don't really disagree with the reasoning, I just disagree with how Apple only is the recipient of such scrutiny. Same deal with payments stuff. And the reason basically boils down to, they have fancy ads and their products look really nice so they must be lying to us.