Advanced Encryption Standard-Ignatius Gonsalves

1. What is AES?2. What is DES?3. Why AES is better than DES?4. Behind the scenes5. Present use of AES

What Is AES?

• Also known as Rijndael•Developed by Joan Daemen and Vincent Rijmen• A Successor of Data Encryption Standard (DES)

What is DES?Data Encryption Standard

Bit length = 56 bitsDesigned 35 years agoPurpose - Secure government communications

A series of challenges were sponsored……

Challenge 1• 1997• 84 days• “ The secret

message is: Many hands make light work”

Challenge 2• 1998• 3 Days• “Time for

those 128-256 bit keys”

Challenge 3• 1999• 22 hrs 15 mins• “See you in

Rome !”

Deep Crack Computer

AES vs DES

DES AESDevelopedKey LengthCipher TypeBlock SizeSecurity

1977 200056 bits 128,192 & 256 bits

Symmetric Block Cipher64 bits 128 bitsInadequate Secure

Behind the scenes

AES

Private Data Ex: Credit card no.

Secret Key

Ciphered Text

AES

Ciphered Text

Secret Key

Private Data

Lets have an in-depth info……..

Byte Substitution

Shift Rows

Mix Columns

Add Round Keys

Encryption

Byte Substitutio

n

• Data is converted into a matrix

Shift Rows• Rows are

shifted to left

Mix Column

Add Round Key

Columns are transformedBy a special

function

Bytes of matrix are x-or’ed to key

Present use Archive and

compression tools

File Encryption

Disk Partitions

Thank You