AES, or the Advanced Encryption Standard, also known
as part of the Rijndael cipher method because it was
taken partly from it, was invented in 2001. This is a
symmetric three-block cipher. Each of these cipher
blocks has a key size of 128-bits and has corresponding
key ciphers of which are from 128-bit to 256-bit in
size. This is one of the most popular ciphers ever in
use, and most that need this type of encryption are
using it, such as the government and the military, as
well as many major vendors and security firms around the
world.
This cipher, which was announced in 2001, underwent a
standardization and evaluation process. In the five
years this evaluation process lasted, AES competed
against 15 other encryption methods. This one was
finally chosen as the standardized, trusted and
unbreakable encryption technique, winning against the
odds to eventually become the first AES method available
to the public. It is also an open source cipher from
which others can use the original code and information
of AES to create new ciphers.
This technique is one of the fastest and can be used in
both software and hardware implementation. It uses a
network consisting of substitution permutation and does
not use the Feistel method to work, unlike its
competition. Using multiple processes, including Key
expansion, an initial round, four subrounds and a final
round, the cipher encrypts the information using a four
by four byte array, which is called a “state” and the
calculations are completed in the finite field. The
amount of rounds used depends on what size the keys are.
For example, a key with 128-bits uses 10 rounds and a
key with 256-bits uses nine rounds.
Attacks against this method of encryption are almost
unheard of. To date, there have been various low level
attacks, however these were forced onto the lower round
encryption than is normally used. The attacks were never
completed because the attackers could not decrypt the
information before they were caught. This method is what
most government and military agencies use for data
protection today.
The initial release of the AES encryption technique came
on the heels of the DES technique’s failure. This one
has a much smaller bit cycle, only a key of 56-bits and
the key and encoding were easily deciphered. Since the
switch to the new standard, AES, the government has kept
its information much safer.
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