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Why Crypto Backdoors Wouldn't Work
An anonymous reader writes: Your devices should come with a government backdoor. That's according to the heads of the FBI, NSA, and DHS. There are many objections, especially that backdoors add massive security risks.
Would backdoors even be effective, though? In a new writeup, a prominent Stanford security researcher argues that crypto backdoors "will not work." Walking step-by-step through a hypothetical backdoored Android, he argues that "in order to make secure apps just slightly more difficult for criminals to obtain, and just slightly less worthwhile for developers, the government would have to go to extraordinary lengths. In an arms race between cryptographic backdoors and secure apps, the United States would inevitably lose."
Would backdoors even be effective, though? In a new writeup, a prominent Stanford security researcher argues that crypto backdoors "will not work." Walking step-by-step through a hypothetical backdoored Android, he argues that "in order to make secure apps just slightly more difficult for criminals to obtain, and just slightly less worthwhile for developers, the government would have to go to extraordinary lengths. In an arms race between cryptographic backdoors and secure apps, the United States would inevitably lose."
I seem to recall that we went through this in the mid to late 90s, where the government insisted any use of strong cryptography should as a matter of law, have a backdoor for the government. Then suddenly they dropped it, and all of us paying attention knew they got their way by some other means. Now post-Snowden, I guess we know what that was, and they're back to beating this horse all over again.
The answer should be no, with absolutely no further discussion.
They can read your RAM
Intel Active Management Technology
(aka vpro, aka vt)
Snowden insisted the journalists remove the battery from their phones and put the phones in the fridge.
That pretty much tells you how useful 'encryption' on Android would be against back doors. None, if you can't protect your speech near the phone you can't protect the password.
Reading the article, it's very intersting. His argument is that you CAN'T backdoor a platform. Summarizing:
1) Say Android rolls over and backdoors the encrypted filesystem.
2) 3rd party apps can use the cryptography library, so Google would also have to backdoor that.
3) Then apps could use a 3rd party crypto library, so gov't would have to compel google to monitor for at least respond to takedown requests for strong crypto 3rd party apps.
4) But apps can easily download and incorporate new code, so Google would have to audit running apps with static and dynamic analysis.
5) Even then, people could use other app stores or sideloads, so Google would have to have an app kill switch option. This would be HUGE INTRUSION and delete apps from people's phones (even innocent people).
6) But how to identify apps? Sideloaded apps could generate a new appID with each download, so Google would have to scan for app characteristics (think antivirus software here).
7) Even if the above worked, browser-based apps could be built that use secure data stores or end-to-end messaging. This would mean the gov't would have to block these web apps, i.e., Internet censorship.
It's just not technically feasible if there is any respect for liberty, not to mention the significant technical challenges involved.
Did you read the article?
I just read the entire article and the author forgot one other solution: the British solution Instead of putting the burden on app developers to include backdoors, or on Google to block apps that don't, put the burden on end users to turn over their keys to police when asked. I'm not saying I like this solution, but it is a solution the author of the article didn't consider. If you make the sentence for non-cooperation long enough, it doesn't really matter if the police find what they're looking for: they can just lock you up for not handing over the keys.
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
Police and government have promoted remote-controlled kill switches on cars for the last 20 years. Although it exists via General Motors OnStar, it's not practical. That will change with vehicle-assisted driving and driver-less cars.
The government already has access via hand-held battering rams and 14 tonne, wheeled wrecking-balls (AKA assault vehicles). Big money and brute force doesn't work on encryption, unless they turn it into rubber-hose decryption (Oblig. XKCD). But the three-letter agencies can't do that 200 times a day, so they want a cheap, simple solution that labels the common people as criminals without rights.
...has the fact a program simply won't work deterred the Government from attempting it anyways?
The government already has access via hand-held battering rams and 14 tonne, wheeled wrecking-balls (AKA assault vehicles). Big money and brute force doesn't work on encryption, unless they turn it into rubber-hose decryption (Oblig. XKCD). But the three-letter agencies can't do that 200 times a day, so they want a cheap, simple solution that labels the common people as criminals without rights.
There are law about that though - a warrant is required for the police to enter my home. DHS is not going to get a warrant to snoop on me.
"Maybe this world is another planet's hell"
Aldous Huxley
I heard a scream come from inside your house, and one of the windows is broken, I think that gives me enough cause the break in.
Seems to me, everytime they talk about this kind of thing, it does exactly what I want. Raise crypto awareness. Keep trying guberment. The more you preach for backdoors, the more people you make aware of the usefulness of crypto. Streisand effect anyone?
No the car analogy isn't valid, because the police do have access to everyone's cars and homes. They get a warrant. They bring a crowbar. Done.
That's the issue with encryption, they can get a warrant giving them the legal right to get in. But there is no crowbar.
I'm not in favor of this, but we do need to understand it is a somewhat unique situation. Strongly encrypted data is not like other property.
But warrants are [whining voice]SOOOO HAAARD. You have to show probable cause and all that stuff. It's too much work.[/whining voice]
Plus, [overly paranoid voice]in the time it takes to get a warrant, a criminal could enact another 9-11 or could destroy the evidence that they were planning that.[/overly paranoid voice].
Those are the reasons why law enforcement needs access to stuff without a warrant. The whiny, paranoid reasons why.
My sci-fi novel, Ghost Thief, is now available from Amazon.com.
The issue is that I shouldn't have to trust the escrow service. Hell, even RSA lost a master key DB, and their entire reputation is built around security.
Surprised nobody posted this yet.
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Lots have been caught with plaintext browser history on their hard drives listing Google queries like "how to dispose of a body". That despite tools to clear or not record such history are easily available. To such end, having a half hearted, optional key escrow may do a lot of good. Let smartphones be encrypted by default, with a copy of the key encrypted with a public key of a cloud company that has an excellent security record. Then if someone forgets their password, and shows up at Apple or Verizon store with a valid ID, they can have their vacation photos back. So can law enforcement if they produce a valid and narrow scope search warrant.
At the same time, people can install custom ROMs that support encryption that is potentially impractical to crack. That's important for many reasons including personal freedom and keeping country's technological edge by encouraging people to develop and understand software. Whistleblowers will get to keep their privacy, and so will a few criminal masterminds. But chances are, the later will have dumb associates who will set their password to 12345. I think a bet that smart people are generally also well intentioned is a good one for our society to make. In the meantime, we don't have to make life of the next Scott Peterson too easy.