Image Steganography Using AES
Today almost all digital services like internet communication, medical and military
imaging systems, multimedia system requires reliable security in storage and
transmission of digital images. Due to faster growth in multimedia technology,
internet and cell phones, there is a need for security in digital images. Therefore
there is a need for image encryption techniques in order to hide images from such
attacks. In this system we use AES (Advanced Encryption Technique) in order to
hide image. Such Encryption technique helps to avoid intrusion attacks.
Working
1. KeyExpansions—round keys are derived from the cipher key using Rijndael’s
key schedule. AES requires a separate 128-bit or 192- bit or256-bit key
block for each round plus one more.
2. InitialRound
1. AddRoundKey—each byte of the state is combined with a block of
the round key using bitwise xor.
3. Rounds
1. SubBytes—a non-linear substitution step where each byte is replaced
with another according to a lookup table.
2. ShiftRows—a transposition step where the last three rows of the
state are shifted cyclically a certain number of steps.
3. MixColumns—a mixing operation which operates on the columns of
the state, combining the four bytes in each column.
4. AddRoundKey
4. Final Round (no MixColumns)
