2 ms·

Certainly reviewed more and certainly infected by the NSA more. Until the taint of the NSA has been removed those are outright no gos.

tptacek 12y ago
I feel like a lot of people probably think the way you do: that software for which source code isn't available is trivially backdoored by NSA. In fact, huge chunks of the billion-dollar software security industry are premised on the idea that this isn't true at all: that you can, for instance, recover the control flow graph from a binary compiled program, and then from that recover an intelligible IR, and then examine that for security flaws. Where, exactly, do you suggest that NSA could have tainted Bitlocker in a manner that wouldn't also implicate Truecrypt?
- pm24601 12y ago
  It goes like this: NSA: "Hi, can you please let us see your source code." (The conversation below happens in your head): <thought-bubble> "Do I want to spend the next 15 years and all my money and life trying to stay out of jail?" "Do I want the IRS to know about trips to the Cayman Islands?" "Do I want my wife to know about my mistress?" </thought-bubble> Me/You: "Sure no problem!" I know its nice to think about that we would the moral high ground. Try doing it alone with just a nice government official.
  - tptacek 12y ago
    This is in no way responsive to my comment, which wasn't about whether the USG would coerce Microsoft.
  - deleted 12y ago
    [deleted]
- Karunamon 12y ago
  Possibly contrived example: An airgapped Windows machine. We've eliminated the possibility of any data exfiltration (all the software vulnerabilities in the world can't transmit on a downed interface), but that does not mean that the encryption itself is not defeated in some way by the existence of a "master key" or some other flaw that allows an attacker to access the data offline. Truecrypt has now been proven to have no such flaws. It's unlikely that Bitlocker will ever be proven in the same way. Anyone that has a legitimate fear of that kind of attack, the bad guys with guns coming in and seizing your stuff, would use Truecrypt over Bitlocker out of an abundance of caution.
  - tptacek 12y ago
    Why exactly is it hard for reverse engineers to discover how Bitlocker is keyed? If it's because it colludes with compromised hardware, why isn't that just as problematic for Truecrypt?
    - Karunamon 12y ago
      It isn't necessarily - but there's a lot of places to hide in a large set of binary blobs. Can any effort spent reverse engineering any program (let alone an operating system!) compete with a line-by-line audit of the source of a single program? Compromised hardware is another matter entirely. The old rule is, "if an attacker has physical access to your machine, it's not your machine anymore", and it's no less true here.
      - tptacek 12y ago
        It's funny you should mention it, because the Windows kernel is among the more comprehensively reverse-engineered codebases in the industry.

tptacek 12y ago

I feel like a lot of people probably think the way you do: that software for which source code isn't available is trivially backdoored by NSA. In fact, huge chunks of the billion-dollar software security industry are premised on the idea that this isn't true at all: that you can, for instance, recover the control flow graph from a binary compiled program, and then from that recover an intelligible IR, and then examine that for security flaws. Where, exactly, do you suggest that NSA could have tainted Bitlocker in a manner that wouldn't also implicate Truecrypt?

pm24601 12y ago
It goes like this: NSA: "Hi, can you please let us see your source code." (The conversation below happens in your head): <thought-bubble> "Do I want to spend the next 15 years and all my money and life trying to stay out of jail?" "Do I want the IRS to know about trips to the Cayman Islands?" "Do I want my wife to know about my mistress?" </thought-bubble> Me/You: "Sure no problem!" I know its nice to think about that we would the moral high ground. Try doing it alone with just a nice government official.
- tptacek 12y ago
  This is in no way responsive to my comment, which wasn't about whether the USG would coerce Microsoft.
- deleted 12y ago
  [deleted]
Karunamon 12y ago
Possibly contrived example: An airgapped Windows machine. We've eliminated the possibility of any data exfiltration (all the software vulnerabilities in the world can't transmit on a downed interface), but that does not mean that the encryption itself is not defeated in some way by the existence of a "master key" or some other flaw that allows an attacker to access the data offline. Truecrypt has now been proven to have no such flaws. It's unlikely that Bitlocker will ever be proven in the same way. Anyone that has a legitimate fear of that kind of attack, the bad guys with guns coming in and seizing your stuff, would use Truecrypt over Bitlocker out of an abundance of caution.
- tptacek 12y ago
  Why exactly is it hard for reverse engineers to discover how Bitlocker is keyed? If it's because it colludes with compromised hardware, why isn't that just as problematic for Truecrypt?
  - Karunamon 12y ago
    It isn't necessarily - but there's a lot of places to hide in a large set of binary blobs. Can any effort spent reverse engineering any program (let alone an operating system!) compete with a line-by-line audit of the source of a single program? Compromised hardware is another matter entirely. The old rule is, "if an attacker has physical access to your machine, it's not your machine anymore", and it's no less true here.
    - tptacek 12y ago
      It's funny you should mention it, because the Windows kernel is among the more comprehensively reverse-engineered codebases in the industry.