Peter_22@xxxxxx wrote: > Jari Ruusu <jariruusu@xxxxxxxxxxxxxxxxxxxxx> wrote: > > Identical ciphertexts leak information. > > I must admit, I didn´t get that. Mkisofs -r dirtree builds an ISO image > which I pipe through aespipe. You mean I shouldn´t use one keyfile twice > for doing this? If same key file is used for multiple partitions, then adversary can easily detect what sectors are identical on different partitions. Identical plaintext data on different sectors on same file system are not a problem because sector number is used in IV computation, and sector number is guaranteed to be unique on one file system. > But you are not concerned that an attacker may find the key to the data in > the first 8192 bytes? Storing key file somewhere else improves security, but re-using same key file for multiple partitions opens a weakness. > 3.3. Example 3 - Encrypted DVD-R [snip] > What would you say about this? Ok for one DVD. Not ok for two or more DVDs. > Will that dvd lock-up again when opening one of its folders containing > some 30,000 files in it? Will there be problems with reads at/after end of > disk and such? Lockups with 30k files on one directory sound more like file system implementation bug. -- Jari Ruusu 1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9 DB 1D EB E3 24 0E A9 DD - Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/
