Download - Cryptography presentation
CRYPTOGRAPHY
DONE BY: WU CHU JUN
INTAN SYAZWANI BTE JA’AFAR
MINDY SOH XI LIN
ENCRYPTION & DECRYPTION KEY USED IN REAL LIFE• Internet browsing has encryption to secure traffic
between user and the site.
• Encryption is used in ATM cards, account passwords
and electronic mails
•Used for file protection
•When one’s operating software automatically updates
over the Internet, it too will use a public key algorithm
to confirm the source of the software being updated
from, and not just someone trying to get into their
computer.
HOW MATHEMATICS HAS A PART TO PLAY IN THIS PROCESS
•Using mathematical formulas or functions
applied to the data to transform the
unprotected information or plaintext, into an
undecipherable format known as ciphertext.
•Having numbers used in encryption and
decryption keys makes it more secure to deliver
information from one party to another, thus
any third party who has access to the hidden,
encrypted data cannot deconstruct or decrypt
WHY DO WE NEED CRYPTOGRAPHY?
• If one does not use encrypted connection with
the server, anyone can get their hands on any
unsecured resources.
•For example, Wi-Fi is vulnerable to what they
call, “eavesdroppers” that are able to review raw
packets from a file sent over the network, and
gain access to contents of clear-text files.
OUR METHOD
• Thus, we would want to distort the original text into an
unreadable one, using mathematical formulas such as scaling,
translation and rotation about 90o in an anti-clockwise
direction.
We decided to implement what we have learnt from chapter 1
(Matrices) and 2 (Linear Transformation). We consider the
message as a graph, thus using the linear transformation
formulas provided.
OPERATION RED CAT TABLE
ENCRYPTION KEY
• Rotation about
90o in an anti-
clockwise
direction (T1)
100
020
002
100
001
010
100
910
601
• Scaling (T2) • Translation (T3)
100
1802
1220
Encryption Key = (T3T2T1)
DECRYPTION KEY
• Rotation about
90o in an anti-
clockwise
direction (T1)
100
001
010
100
910
601
100
05.00
005.0
100
605.0
95.00
• Scaling (T2) • Translation (T3)
Decryption Key = (T1-1T2
-
1T3-1)
PROCESS
•Message: Maths Project :(
11111111
)(:
()()(
nullteoPha
spacecjrspacetM
11111111
02145258573467
70237563524584
*Matrix of message based on Operation Red Cat table
ENCRYPTION PROCESS
100
1802
1220
11111111
02145258573467
70237563524584
11111111
15822921308822108186
12307838158134802
DECRYPTION PROCESS
100
605.0
95.00
11111111
15822921308822108186
12307838158134802
11111111
02145258573467
70237563524584
TA-DAAAA!
• Referring back to the Operation Red Cat
table… message decrypted: Maths Project
:(
11111111
)(:
()()(
nullteoPha
spacecjrspacetM
11111111
02145258573467
70237563524584
THANK YOU FOR YOUR ATTENTION!