DATA PROTECTION
(C) Himik's ZxZ / PoS-Wt
Today, I want to speak on information security
copying. There are so many
Algorithm protection and analysis of information
but each has its drawbacks.
I have to say: perfect defense is impossible to write, because
it will still be broken in the shortest possible time. How to
Examples of our memory? Now try remember some of them:
1. Disk Control Utility
(DCU by N. Rodionov).
It should be noted that the program was written
just great! In those days, hardly
you could find a decent replacement, but here
Problem: In the most recent version was
used copy protection system. What is its essence? The program
starts thought for a while, and then swore,
that it is an unauthorized copy. In
What was the trick? We ourselves are a long time
know what we do, but then one day we
came across the author's program for
"Authorize" a copy of DCU. First, we
its hard yuzali, and then decided to see what happens. If I am
right now memory does not fail on zero-path
disc was created with the sector number # FB
(253), but when you start the DCU to give commands
Read this sector, and on the basis of reading to construct
further management of the program. Everything was simple: if
sector is, then he read, and no error was as if the sector is
absent, there was a transition in error, processing is assumed
the DCU - as a result, catch errors, we conclude - no sector,
and then the program is copied illegally. Such protection can
copy almost any copiers.
2. ZX-Format Electronic Computer Magazine.
In the first issues of protection as such was absent, but then
there was a program MicroProtector, with the help of which
became defend this journal. Of course, initially had a problem
with copying, but then in our hands got Mc.Donald Copy, which
did an excellent copy of the disc.
A little later a new version of MicroProtector: when trying to
copy protection Mc.Donald gave the screen a lot of attributes
and hung up. That fiasco: protection has become steeper,
breaking his hands were lazy, but do nothing,
had to break.
What is security? Then the algorithm is more difficult,
than in the first example, because job security
based on changing the index of the field track, writing there
his <filthy> tags. Why could not we make a copy? The algorithm
is based on the analysis copyist index field track to re-create
the disc format. Well, of course, if there come across quite
unrealistic combination of bytes copyist then just went crazy
and hanged. Where to put the protection? Everything is simple:
the file you want, for example, boot.B, spells out a piece of
code (like a virus?), which reads and checks for labels on
drive, and on the basis of this cipher code rasksorival the
file, which should have been run, and then passed control to it.
What are the disadvantages of this? Well, first of all at once
we can determine which sits analyzer protection, and parse it
into smaller parts, and subsequently remove the protection to
the dogs. This feature did not miss a
SysOp (SP) and the Sleeping Man (all from group
Power Of Sound), and wrote for antisystems
this type of protection. The program received
name S.A.P.S. (Super AntiProtection
System). In addition to the system MicroProtector, this
program eliminates the protection of Grid v1.0, which I will
discuss later.
3. UFO: Enemy Unknown (by V. Mednonogov)
It just so happens that with this game we did not
were no special problems, because We had a copyist who made a
working copy protected disk.
Now note that this is probably the most
advanced protection for those times, but the mechanism
protection acts, and to this day. Note
algorithm - a modified and analysis
index space disk tracks. If someone knows something in this
space write service information to the controller, such as:
sector size, No. sector and track, and synchronizes the space
and some more bells and whistles. According to my information,
the first program that used a similar algorithm of protection,
but already on a disk with more or less hidden
analysis system - Grid Protection System
v1.0. I, as one of the authors
program, it was an order from Moscow to
writing it on the local market huckster - SoftStar'a. I have
developed and painted protection algorithm and analysis
paper, and all of the code did Alex
Heather / PoS. But SoftStar was a natural huckster, and when
the program was tell him we have not received it nichego.Ya'm
not talking about money but about the new software which he has
always been. And soon we're do SAPS, which removes this
protection, and protection from the inside turned out to be
small leaky. Worst-first. (*. Com)
Now I will tell my opinion about what should be protected drive
(for example candy bars):
1. Hidden directory of the drive, or no
absent.
2. Preferably, all possible commands
TR-DOS startup disk should occur.
3. Shall maintain files on a disk, and
if the disk is only one
file - just run it by passing
boot.
4. Protection should take as little as possible
disk space.
5. The disc should not cause a crash
copiers to bummer to come not
immediately, but after a 30-minute and copying
of.
6. Basic-files on the disk should work
only in protected mode, ie if
a wise man climbed poking drive dock
torus in the disk data in order to simply
find the program that he wants to
this drive to be expected .
7. The process of running a secure disk USD
wives to be simple and fast.
8. Even if you have kept a running boot
MAGICom or some other crap in memory
we should not find a directory to disk.
9. Stable work on all types of disco
conclusions.
10. One hundred percent run programs from the boot.
So we got a bunch of requirements for protection, but I did not
say most important - the protection should be such that you can
not copy the most advanced copiers. Personally, I know: such
protection exists, and it is attached to this issue of the
newspaper. These are two versions of Grid v2.0 (for monoblock
files) and Grid v3.0 (for read with name programm). Go tell: on
emulators this thing will not work because not yet
this format the disk image, which would contain all of that
index information, which is used in this type of protection.
Its current disadvantage is that you can
trace the entire course of events analyzer
through a variety of monitors, debuggers, but it does not give
specific results. Copy, and most importantly, write
antiprotektor yet managed to anyone. May be simply not to
bother, or maybe - we could not. Now about the program itself.
1. Each Basic-disk file an original
encrypted and decrypted directly before running in memory.
2. Index on the disk is generated
always random and has a length of up to
64 characters, including a triple conversion system.
3. In addition to the random marks on a disc recorded special
copyright mark, which is the very first analysis of the disk.
4. Directory of the drive being upgraded, divided into several
different parts and originally encrypted by parts. 5.
Recordable disk boot has a length all 16 sectors in the light
of music accompaniment.
6. The entire directory and the first part of the system
Disk Analysis is the zero track
disc.
7. Analysis of the protection is done during the installation,
ie put the defense, and then test for
ability to use, and if there
errors, then all the keys are generated again, and
repeatedly until the disc is protected until
mark will not be perfect. This leads to
increase in the percentage of efficiency of protection on other
computers. 8. In the analyzer tags are inserted time
delay to avoid asynchronous on drives from different
manufacturers, and also the turbo controllers drive.
9. If the disk is only one file, then after
security check, he immediately starts. This
handy if you have protected their game - why
once again show boot.
I think that's enough. Everyone, if they wish, be able to test
this protection itself. In version 2.0, there is one drawback:
before protection of the drive must be prepared, after which
write the necessary software on it, and after
This put the defense. What does the training? Just clears the
disk directory and sets the first free track is not one, but
two. This is due to the fact that the boot has a fixed data on
the location at disk.
In version 3.0 there is no such, but there is, in fact,
protection is more open, because No auto-drive and directory
part is. Anyway, in 1996, copy
protected discs could not be any on the ZX,
or at IBM. Now, it is unlikely.
