2 expanded posts ยท every known parent and child
Norton might let interested people exhamine the code, far as I know nobody has asked, but one mode is DES. It seems to me if Norton were ok, you could encrypt with Norton and decrypt with any other hardware/software implimention of DES. Unless Norton does something really dumb like stashing the key on disk somewhere, it would seem to me that this would varify Norton doing DES per the book. Have I missed something? Keith
-- Does it use CBC mode, or what?
-- Where does it get an initialization vector?
-- Assuming CBC or some other chaining mode, is an entire file
encrypted as a single unit? Or is each file block encrypted,
beginning with a quickly-determined initialization vector,
and what are they?
-- If the length of the file is not a multiple of 8 bytes (the
DES cyperblock size), how is the boundary condition handled?
-- Are filenames encrypted? How? Other directory information?
If the source to Norton were not published, but rigorous specs were
available that could be verified by trying it an a bunch of files,
and if one can account for all bytes on disk that change when the
package is used (so that we know it is not escrowing keys or doing
anthing stupid with them), then I might feel comfortable about
the product.
I don't think this is unreasonable to ask. It would particularly
make me feel safe about the problems we heard described earlier, where
someone was unable to decrypt files. If I can deploy and use my own
decryption mechanism to doublecheck Norton, then it's more likely
my own fault if I cannot recover some file.
strick