Hello all, A few years ago a university administration staff member asked an assistant to wipe out all his files in preparation for retirement. He got angry when he soon found his web searches in the browser history and cache, and asked how is that possible.
No "secure" delete would have helped him, but standard delete would have been fully adequate had he only known what to delete. There was no chance in hell that anyone would engage in a block device scanning of his abandoned disk, much less track alignment variation analysis. Such are the vast majority of the cases. Even moderate security is a challenge, and a "secure delete" facility is one of the tools. Considering how the word processors create recovery files, auto-saves, backups, how the documents get automatically indexed, there are many parts of this equation. On the other hand, it is not completely true that encryption does not help against track alignment analysis because "they" can find the key file and beat the passphrase out of me. Beating the passphrase out of me can easily become quite expensive - not only for me :). In addition, there is no guarantee that the writes of sensitive material will happen with any larger misalignment than usual, to make those bits reliably recoverable. Even though sophisticated methods can reveal up to twenty layers of old data, they can only do so with an increasingly high bit error rate. It does not take many bit errors to ruin the prospect of decryption, except for the most outlandish recovery budgets. So, even a fairly cheap and quick encryption system combined with a "secure delete" facility makes it many orders of magnitude more expensive to recover any information from the disk. While it is hardly the first priority, there might still be many customers that will one day be willing to pay for this. Regards, Enrique
