
30-12-2007, 13:24
|
Registered User
|
|
Join Date: Apr 2005
Location: Germany
Posts: 332
Thanks: 0
Thanked 3 Times in 2 Posts
|
|
@!HaGaR!
Google Translation Russian->English of an article by AlB:
Quote:
What exactly is a ISOProtection?
As we all know, starfors since version 3.33 .* introduced a lock file system, but for pure coincidence, it turned out that starfors did not check on the integrity of the contents of the disc, omission was immediately used's a mini images (a disk with reduced size).
In fact, according to the developers tuls demon, with the possibility of the use of the images reduced in size was totally unexpected for them is themselves, in fact, this opportunity was nothing more than a mistake emulation (Pochasche to such useful errors ).
Blocking is a one additional cycle, which the defence has done after verification of physical properties of the disk. In detail, first read sector to test the physical properties of the disk of 140 sectors, and then already read 24 ~ random "garbage" sector aimed at making this a lock measurable, and thereby identify emulation. With the advent of mini images, users were able to circumvent the lock file system, as the sector is no longer required to deduct from the image they generirovalis time being slaughtered in the summer of zeroes and completely unlike a full no languishing in the queue at that time, which usually starfors includes a lock file system.
But such an opportunity could be used so long as the starfors did not check their contents. There is a natural step for the protection of adding banalneyshey was checking some sectors on their integrity for the purpose of enforcement of a full, nothing in this clever course not, and thus was born the so-called ISOProtection that in general the majority of other defence and had no surplus name.
Publisher creates a disk image, then drive is scanned, randomly chosen different sectors with different contents, they generated checksums, then these amounts are encrypted from foreign eyes and those already implemented encrypted amount of 6 sectors, which are appended to the end of the finished image.
You can certainly speculate about the number of sectors for which created checksums, but their number is strictly limited, because this method is applied to CD or DVD disks, not at all desire to fit in 12228 byte checksums, for example, for a 350000-CD sectors. But even if they will be thousands or less / more, this would already be enough to hinder the possibility of identifying these sectors because of the game they are playing different, but accidentally deducted only two sectors, and not the fact that everything at once tested.
The test for the maintenance is a further interim cycle of 8 working between sectors of the physical test of the 140 sectors, and the cycle with random "garbage" sectors, where the braking...
|
|