I am reading this piece about Ray Ozzie’s key escrow proposal in Wired. A few random thoughts.https://www.wired.com/story/crypto-war-clear-encryption …
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1. First off, from a technical PoV this proposal (like most others) implies the existence of some ‘master key to all iPhones’. When that key gets stolen, there’s really no mechanism to detect it.pic.twitter.com/SIM7y5gdRF
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2. More critically, Ozzie’s proposal relies on ‘a special chip inside the phone’ that bricks the phone if someone abuses the access mechanism. This is cute. It’s also (at present) a big fat giant elephant in the room.pic.twitter.com/swtkNTmSxg
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3. Let’s be more clear about this. All Apple phones have a similar chip inside of them. This chip is designed to prevent people from brute-forcing the passcode by limiting the number of attempts you can make. At present, every one of these chips appears to be completely broken.
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4. Specifically, there is some (as yet unknown) exploit that can completely bypass the internal protections provided by Apple’s Secure Enclave Processor. So effectively “the chip” Ozzie relies on is now broken.http://www.dailymail.co.uk/sciencetech/article-5613597/Police-claim-unlock-iPhone-using-mysterious-10-000-GrayKey-box.html …
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5. When you’re proposing a system that will affect the security of a billion Apple devices, and your proposal says “assume a lock nobody can break”, you’d better have some plan for building such a lock.
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6. From my perspective, this problem alone is sufficient to make the Ozzie proposal unworkable.
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7. ”Hold on,” I hear you cry, “so what if a few government agencies and hackers have a fancy 0day. That doesn’t mean anyone else will get it!” Have I got a headline for you. https://motherboard.vice.com/amp/en_us/article/qvx9jx/iphone-crackers-grayshift-graykey-leaked-code-extortion …pic.twitter.com/cPxW0Fv6c1
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8. So let’s recap. We are going to insert a backdoor into billions of devices. It’s security relies on a chip that is now broken. AND the people who broke that chip MAY HAVE LEAKED THEIR CODE TO EXTORTIONISTS ON THE INTERNET.
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9. The extortionists are apparently demanding 2 bitcoins.pic.twitter.com/gOKDhdWzHc
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10. While this is not personal to Ozzie and I don’t hold him responsible for this, this episode exhibits all the characteristics of ‘crypto backdoor’ proposals since time began.
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11. Assumes a security technology with yet-to-be-achieved resilience to attacks (insider and outsider)
This technology is broken
The break is comically accessible even by random criminals, not sophisticated nation state attackers Show this thread -
12. And honestly this is a GOOD thing — that a key component of Ozzie’s proposal is being broken in a comical, public, horrifying way. Because other parts will also be broken. We just won’t know.
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13. I’m thinking specifically of the ideas that assume we can include a ‘master iPhone decryption key’ inside an HSM and everything will just be fine. Because “people store keys all the time and it’s ok.”
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14. (I could go on about Hardware Security Modules for days while sounding like a lunatic. I promise not to. Read this instead.)https://cryptosense.com/blog/the-untold-story-of-pkcs11-hsm-vulnerabilities/ …
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15. (Ok I lied. You might also ask where HSM manufacturers recruit their knowledgeable crypto/security employees. Hint: one of the biggest vendors is located here in Maryland. I assume similar things are true of the non-US manufactures.)
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16. (Seriously, LinkedIn is your friend. Also, super nice people! I love you guys.)
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17. Leaving hardware aside, the simplest answer to the suggestion that companies like Apple can “easily keep secrets” is that they *haven’t been able to*. Apple had a big stack of source code stolen last Fall. https://www.theverge.com/platform/amp/2018/2/9/16997266/apple-source-code-leak-intern-internal-tools-jailbreaking-github-ios-9 …
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18. While they haven’t turned up, the rumour I’ve heard from the jailbreaking community is that the leaked Apple code also included signing keys. So much for keeping secrets.
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19. I would also inquire, without claiming any particular knowledge, whether Cellebrite or GrayKey have any recent Apple iOS engineers on the technical teams that developed their current iOS exploits.
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20. This thread has gone on for way too long and I haven’t said half of what I wanted to say. But rather than bother you anymore, I’ll finish up with a quote from
@ErrataRob, who sums up my feelings perfectly.pic.twitter.com/WEF31iHa70
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End of conversation
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@threadreaderapp Kindly unroll -
Hello please find the unroll here: https://threadreaderapp.com/thread/989222719056220160.html … Talk to you soon.
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