Encrypted discs must be managed in some way especially in companies.
We need to have the possibility of remote administration and remote program configuration that will
encrypt and decrypt data.
After all we will not do it to each computer separately.
In addition some embedded emergency mode is mandatory.
What do you do in a situation when a user with encrypted data for or the user encrypted the entire disk
himself forgets a password.
For example the password that allows him to decrypt the disk
there must be some way to decrypt data on the disk on behalf of the user.
Of course this affects security because its based on trust to the administrator
additional benefits of programs that encrypt the disks could be something like hiding the fact of the
presence of data on the disk.
This is something that has not been implemented in bit locker.
This is something that makes your crypt stand out as compared to a bit Lucker your crypt has such functionality
that when one disk is encrypted it will create a second disk encrypted with a different key.
Since both these disks are encrypted the analysis of these disks content for example on the computer
is off does not show any difference between one encrypted disk and the other.
In general it should be maximum pseudo random data.
Now if someone asks us to decrypt a disk in most cases those who are authorized to do so such as the
police if they ask us we have the obligation to reveal to them the password for this type of security.
If we have the password to one disk it will be decrypted and its content made available.
If however we dont give a second password everything that was encrypted and was on the internal hard
disk will remain invisible.
At least in theory
an additional advantage to disk encryption could also be checking the integrity of the computer.
This function is only available in bit locker and is not available in true crypt its idea is that interference
in the computer for example moving the hard disk or a change in the order of the starting devices causes
automatic blocking of the encrypted disk
we've already mentioned authenticity.
We said that a signature is used for However in the case of disks that's not possible since the sector
has a fixed sector size.
We can't force manufacturers of hard disks and low level software to reserve for us a few extra bytes
in each sector.
We also can't write checksums to another sector since there are programs that are based on the fact
that sectors are independent of each other
examples of such programs or database servers which in their own way manage writing and reading it cannot
be that a change in data in one sector causes their automatic change in another sector.
This is what would happen if a check somewhere there
we could solve the problem by artificially doubling the size of the sector.
Then all the problems are solved.
We have a lot of space for the checksum.
In addition the operating system is only half of the sectors and there is no relationship between the
sectors.
Unfortunately we'd have to convince users that when buying for example a 500 gigabyte disk it really
has to be 250 gigabytes we could meet some resistance.
Therefore disk encryption software instead of using Macs signature's broadcast bits on as many sectors
as possible.
In addition to encryption specific sectors use keys to avoid simple mathematic relationship
well then how can we encrypt our hard disk.
The first decision we make is the choice of algorithm Most often we can choose Advanced Encryption Standard
ABS
this algorithm won the competition for a successor of the DSL got rhythm which was started in 1997 and
lasted for the following three years.
It was a moment in time when that was repeatedly proven that D.S. can be cracked in less than 24 hours.
It was time for it to be changed.
The change occurred through an open competition anyone could submit an algorithm proposal for three
years.
Professionals mathematicians and cryptographers analyze the actions of various algorithms and tried
to crack them
yes won the competition.
Thus security was confirmed.
In addition yes is relatively quick in so far as that we can use 128 keys.
The disadvantage of ABS is that if we double the Keeling's the encryption and decryption process is
clearly slowed down performance may be 40 or 50 percent lower.
Without a doubt it's advantages it's resistance to certain sophisticated cryptanalysis attempts together
with this more and more popular our single chip processors.
They're both more powerful and more functional performing more and more tasks.
We can use single chip processors to encrypt it turned out however the safe algorithms implemented in
single chip processors are not that safe.
You can get the key from them by analyzing the data transferred between individual blocks between physical
devices soldered on the keyboard.
Among other things you can see the power consumption of individual Microcircuits.
This is important because certain operations require more power than others for example multiplication
is more expensive than addition.
There's also a relationship between the key and the cost of operation which can be precisely measured
using.
For example an oscilloscope multiplication by 0 for example is always faster and requires less resources
than multiplication by any other number.
Analyzing the data transferred between the modules conclusions can be made regarding the construction
of the key an interesting fact is that in order to protect against such attacks the creators of the
single chip solution started to protect critically important modules with paste after removing the housing
immediately saw where the interesting modules are E.S. is designed to balance the number of different
operations such as addition and multiplication.
It's resistant to this type of analysis.
When selecting an encryption algorithm we also have the choice of the serpent algorithm.
This is just as safe as an ESL Garou of them are clearly much slower and nonstandard this algorithm
took second place in the competition.
The next algorithm is Twofish.
This is Bruce Schneier algorithm who also participated in the competition.