This the slide used to explain exactly what advanced encryption standard algorithm is in a very easy way. First we have mentioned the branch from where exactly is this algorithm associated with. We have defined some concepts which are the prerequisites we need to learn before studying this algorithm. We have told the design of this algorithm exclusively with every keeping every step and concept in the mind.
3. CRYPTOGRAPHY
Cryptography is the science
and study of methods of
protecting data in computer
and communication systems
from unauthorized disclosure
and modification.
4. QUOTE
Here’s a quote from
a famous person
“Cryptography is the ultimate form of
nonviolent direct action”
—Julian Assange
5. What is
Encryption
and
Decryption?
★ Encryption is the process of translating
plain text data (plaintext) into
something that appears to be random
and meaningless (ciphertext).
★ Decryption is the process of converting
ciphertext back to plaintext.
6. Why use Encryption ?
Encryption is important because it allows you to
securely protect data that you don't want anyone
else to have access to.
7. DEFINITION OF CONCEPTS
Private Key
A private key, also known as a
secret key, is a variable in
cryptography that is used with an
algorithm to encrypt and decrypt
code.
Public Key
Everyone else, who wants to
communicate with the Sender is
given a key called the Public Key.
Symmetric Encryption
Symmetric Encryption is when a
secret key is leveraged for both
encryption and decryption
functions.
Asymmetric Encryption
Anyone can encrypt messages
using a public key, but only the
holder of the paired private key can
decrypt such a message.
01
03
02
04
8. Advanced
Encryption Standard
It is a symmetric block cipher algorithm
chosen by the U.S. government to protect
classified information and is implemented in
software and hardware throughout the world
to encrypt sensitive data.
It was intended to be easy to
implement in hardware and software,
as well as in restricted environments.
9. CREDITS: This presentation template
was created by Slidesgo, including
icons by Flaticon, and infographics &
images by Freepik
Bit 0 or 1
1 byte = 8 bits
1 word = 4 bytes
1 block = 4 words
State ( 4×4)
16 bytes
Stores intermediate
result.
Rounds Size of keys
10 128
12 192
14 256
It has 10/12/14 rounds.
Where block size 128 bits =
16 byes (4 words).
No. of keys generated = N + 1
10. INPUT ARRAY (4X4)
4 Words
128 bits
16 bytes
1 byte
STATE ARRAY (4X4)
S0,0
S1,0
S2,0
S3,0
S0,1
S1,1
S2,1
S3,1
S0,2
S1,2
S2,2
S3,2
S0,3
S1,3
S2,3
S3,3
3rd byte of
0th word
W0
W1
W2
W3
13. SUBSTITUTION
AES uses substitution. Substitution
is done for each byte.
Only one table is used for
transformation of bytes that means
if two bytes are same then
transformation is also same.
SUBBYTES
The first transformation, SubBytes,
is used at the encryption site. To
substitute a byte, we interpret the
byte as two hexadecimal digits.
1st hexadecimal digit = Row
2nd hexadecimal digit = Column
18. Take each word or column i.e.
4 bytes or 4x1 matrix and
multiply it with the constant
matrix
The output is 4x1 matrix of 4
bytes and is stored in output
or state matrix.
19. Key Adding
AddRoundKey proceeds one
column at a time.
AddRoundKey adds a round
key word with each state
column matrix; the operation
in AddRoundKey is matrix
addition.
20.
21. Conclusion
● Cryptography
● Encryption and Decryption
● Private key, public key, Symmetric
Encryption, Asymmetric Encryption.
● What is aes?
● General design of aes
