Critical Review of DES and AES: A Comparative Analysis of Encryption Standards

CSC8419 - CRYPTOGRAPHY AND SECURITY -
ASSIGNMENT 3
Topic: Critically Reviewing DES and AES

Table of Contents
Introduction...........................................................................................................................................2
What is DES??........................................................................................................................................2
What is AES??........................................................................................................................................4
AES features:.....................................................................................................................................4
Security:.........................................................................................................................................5
Cost:...............................................................................................................................................5
Security..........................................................................................................................................5
Attacks:..................................................................................................................................................8
Solution (How Cryptography technology is used to provide the security).............................................9
Conclusion:..........................................................................................................................................11
Recommendations:..............................................................................................................................11
References:..........................................................................................................................................12
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Introduction
Communication has always been the only medium to be connected in this world. The
communication can take place through various methods like the phone to phone calls or by sending
messages or emails containing the useful information. But due to the advancement in technology,
this important information can easily be hacked by the experts and can be misused. When it comes
to the transfer of very highly secured messages, especially by the government organisations and
defense sectors utmost care is needed as a little information leak in the wrong hands can have
several major effects not only on the organisation but as a whole country. Therefore to protect the
data sent between the user and receiver one needs to encrypt the data, so no one is allowed to
access the data without permission and a specific password or a key. For this various method were
adopted such as DES and AES which will be discussed here in this text. We will have a look at how
they work, which is better than the other and how it can be improved to a certain extent (Mankotia,
2015).
What is DES??
DES stands for data encryption standard which is a block cipher that describes a cryptographic key
and a certain algorithm is put on the documents or the block. This can be done simultaneously too
many bits at a time instead of a single bit. To encrypt a plain text message, it makes a group of 64-bit
blocks a piece. Now each block is encoded by a secret key into a 64-bit ciphertext with the help of
substitution and permutation. This procedure includes 16 rounds and could execute in four diverse
modes. This can either work individually or can make the block codes to depend on the previous
block. And this way a successful encrypted message is directed to the receiver. Now at the receiver
end, the text needs to be decrypted before it can be read. The decryption process is a complete
inverse process of the encoding technique. It monitors the equivalent steps just the direction of the
steps is reversed in which a key is used (Olaleye, 2017).
For any figure, the primary and the maximum critical or easy method to assault is the animal
electricity which includes the hit and trial method with the aid of trying every key until the point that
the right key is found. The length of the important thing comes to a decision the amount of doable
keys and as a consequence the safety and easy manner to cope with this attack. DES uses a 64 bit
key in its encryption process but out of this eight of these is already booked for parity checks and so
we have limited our bits of the key only to fifty-six bits. Hence the maximum number of trials to find
the correct key are 2^56, that is 72057594037927936 attempts.
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In the early 1970s, the researchers of IBM designed this DES system and the U.S. government
adopted this as an authorized federal info n processing standard (FIPS) in 1977 for the confidential
and profitable classified computer data of government. This became the first encryption process to
be accepted and the U.S. government approved this procedure for public disclosure. Due to this step
many companies in which high encryption required adopted DES quickly and such as the financial
services. Its simplicity increased its uses in the embedded systems like the SIM cards, smart cards,
and many system devices which require encryption like the setup boxes, modems, and router
(Mankotia, 2015).
This technique was widely used at that time but due to the upcoming technologies, it became easier
to crack these encrypted messages. Many felt that 56 bit was inadequate even before its standard
adoption. They also believed that interference from the NSA side has weakened the codes and
algorithm originally written by the IBM. But this was still widely used and the most trusted
encryption till the 1990s. But in 1998, a computer constructed through the electronic frontier
foundation was capable to crash the encrypted message within 56 hours. Which created a problem
for the users? Later by binding the control of the thousands of interacted computers, the decryption
time was reduced from 56 hours to 22 hours only.
Due to its way of cracking and backward compatibility in many cases, trusting today on DES for
information confidentially is a thoughtful security fault in every computer system and must be
evaded. With the advancement, there is much new secure algorithm are accessible now, and people
do not need to rely on these previously build algorithms. DES is more like a cheap suitcase box,
which can keep the data or content safe just by the honest people but cannot stop the determined
thief. So our problem of security remains the same and we would look for some other options in
order to keep our data safe and protect it from being hacked by the malfunctions. One such
algorithm is AES which we will further discuss in our report here (Chandrasekar, 2017).
Despite being reached at the end of the usability and usefulness of its life, The access of DES
dependably served to boost the research of cryptography and the improvement of latest encryption
calculations. Until the point that DES wasn't presented, cryptography was the stupid craftsmanship
restrained to the domain names of the military and authorities perception institutions as it had
been. Because of the open concept of DES, it gave numerous open doorways, as an example, in
scholastics, for mathematicians or all of us intrigued by way of protection. As they could
contemplate how the calculations functioned and could endeavour to split them. Basically in terms
of a new puzzle or some craze. A whole new industry was born and opened the chances for more
and more development (Prajapati, 2014).
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