Re: [patch] cgd
Steven Bellovin <[email protected]> Thu, 2 Dec 2010 07:13:24 -0500
| Newsgroups | gmane.os.netbsd.devel.crypto |
|---|---|
| Message-ID | <[email protected]> |
>> > > I'm of the opinion that integrity checking best belongs in the file > system layer because it necessarily involves increasing the size > of the data which for a pseudo-disk is very expensive indeed. If > you decide to break a single disk write into multiple writes then > you must also necessarily maintain state on the disk of what you > are doing in case you crash in the midst of a write. This would > involve turning each single sector write into at least three separate > writes. At the file system layer, you have no such problem and > can preserve performance while also ensuring integrity. (Unless > you can present 500 byte sectors to the rest of the kernel.) I'm fond of the scheme described in http://www.cs.unc.edu/~reiter/papers/2005/NDSS.pdf (NDSS 2005). --Steve Bellovin, http://www.cs.columbia.edu/~smb