Re: Hard Drive Destruct System?

From: Walter Roberson (
Date: 11/28/04

Date: 28 Nov 2004 08:52:02 GMT

In article <coas47$ijt$>, Al Dykes <> wrote:
|In article <coaok5$eb0$>,
|Walter Roberson <> wrote:

|>In practice, you can't use a single encryption over a whole drive,
|>because you have to be able to randomly read or wrote from the middle of
|>it without having to decrypt everything before that point (read) or
|>re-encrypt everything after that point (write.) And directory structures

|Offhand I can't see any problem with en/decrypting data in 512 byte
|blocks as sectors are read/written to disk.

If you are using the same key each time, that scheme would suffer
a lot from "known plaintext" attacks. For example,
All blocks of NULLs would encrypt exactly the same way, and
the first 64 bytes of most non-text files would be relatively
consistant amongst filetypes, allowing you a fairly good idea
of what kind of file something was without decrypting it.

Is "meme" descriptive or perscriptive? Does the knowledge that
memes exist not subtly encourage the creation of more memes?
   -- A Child's Garden Of Memes