Max A. wrote: > Hello! > > Could anybody familiar with PGP products look at the following page > and explain in brief what it is about and what are consequences of the > described bug?
1. The disk is encrypted using a long, secure, random, symmetric en/de-cryption key. (EDK for short). 2. The EDK is encrypted with a passphrase and stored in a header at the start of the encrypted disk 3. If you change the passphrase on the disk, it simply reencrypts the EDK using the new passphrase. It does not generate a new EDK and it does not re-encrypt the entire disk. 4. Therefore the EDK itself is still the same, and if you overwrite the new header (with the EDK encrypted by the new passphrase) using a stored copy of the old header (with the same EDK encrypted under the old passphrase), you have effectively changed the passphrase back - without having to have knowledge of the new passphrase - and can now regain access using the old passphrase. The guy who wrote that page posted a thread about it a while ago, I think it was on FD or perhaps Bugtraq. His interpretation is somewhat coloured by his transparent belief that these are big corporate monstrosities and hence /must/ be evil. His website is full of significant exaggerations/inaccuracies; for instance, when he claims that you can break the decryption using a debugger, he forgets to mention that this only applies to a disk where you originally knew the passphrase and have since changed it. It's more of a usage/documentation issue, really; an end-user might believe that changing the passphrase re-encrypted the entire disk beyond their ability to retrieve it. cheers, DaveK -- Can't think of a witty .sigline today.... --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]