I think it would be better if applications could provide their own encryption. Applications know better how to cryptographically protect content. For instance: we use GPGMail for our email at Matasano. The operating system could not do a better job of encrypting email messages than GPGMail does.
I understand your point. "Encrypt at the highest layer you can" is an ideal, and achieving the ideal is not always worth the expense. Some lowest-common-denominator crypto in the OS is valuable. But disk block crypto is a pretty crappy lowest common denominator, as this article is at pains to say. What part of it do you disagree with?
If every application provided their own encryption, most of them would get it wrong, and it still wouldn't protect important metadata. I don't think that's much of an ideal.
I don't have an issue with adding application specific encryption, as long as you also keep doing it at a suitable "lowest-common-denominator" layer.
A more achievable ideal would be for every layer to do strong integrity checking.
I agree that one of the costs for doing everything at the highest possible layer is the potential for mistakes. I don't think every application should invent their own cryptosystem; I think most applications would be well-served with Nacl, and I think things like GPGMail show another good path forward.
I agree that it would be good if the lowest common denominator provided integrity checking, but as we can see with XTS, sector-level encryption makes that hard. Hence the article. :)
Comments
I think it would be better if applications could provide their own encryption. Applications know better how to cryptographically protect content. For instance: we use GPGMail for our email at Matasano. The operating system could not do a better job of encrypting email messages than GPGMail does.
I understand your point. "Encrypt at the highest layer you can" is an ideal, and achieving the ideal is not always worth the expense. Some lowest-common-denominator crypto in the OS is valuable. But disk block crypto is a pretty crappy lowest common denominator, as this article is at pains to say. What part of it do you disagree with?
If every application provided their own encryption, most of them would get it wrong, and it still wouldn't protect important metadata. I don't think that's much of an ideal.
I don't have an issue with adding application specific encryption, as long as you also keep doing it at a suitable "lowest-common-denominator" layer.
A more achievable ideal would be for every layer to do strong integrity checking.
I agree that one of the costs for doing everything at the highest possible layer is the potential for mistakes. I don't think every application should invent their own cryptosystem; I think most applications would be well-served with Nacl, and I think things like GPGMail show another good path forward.
I agree that it would be good if the lowest common denominator provided integrity checking, but as we can see with XTS, sector-level encryption makes that hard. Hence the article. :)