1_Encryption

1_Encryption

1. Why Encryption?

   • Transmitting over a network is a threat to security
     • Reliable,fast and robust system
       • Transmit(1,2)
         • Via Network
           • the Internet
           • e-commerce
         • Mobile Phones
         • Wireless Systems
         • Bluetooth Devices
       • Storing
   • Ehitcal issues in information systems
   • Frequent flow of digital images across the world over transmission media
     • Military Image DB
     • Confidential Video Conferencing
     • Medical Images
     • Online pesonal phtographs
     • Satelite Information(2)
     • Tele medicine/Medical Imaging Systems(2)
     • Pulic and Private flow((2)
   • Image data used in many sensitive applications(2)
   • through loss or theft in devices(2)
     • It may reveal useful info to other parties
   • Information Security is an utmost concern(3)
   • Encryption ensures security(3)

2. Encryption Algorithms

   • Many algorithms during the last decade
     • Proposed in mid-1990s(2,8)
   • Chaos based
     • Good For Practical Use(1)
       • Good Combination of Speed
       • High Security
       • Complexity
       • Reasonable computational overheads + computational power
     • New design in cryptography(1)
     • New trend
     • Evolution(1)
   • Traditional Ciphers(1)
     • IDEA,AES,DES,RSA
     • Not Suitable(1)
       • Need large compuatational power
       • High computing power
   • Alg have diff characteristics(2)
     • Strengths & Weakness
       • Security Level
       • Speed
       • Similarity bet orign im and dec. im
   • Different types(3)
     • Position Permutation
     • Value Transformation
     • Visual Transformation
   • Visual Cryptography(3)

3. Characteristics of Digital Images(1)

   • Redundancy of data
   • Strong correlation among adjacent pixels
   • Being less sensitive

4. What is Encryption?(2)

   • It is a process.
   • Transforming the plain image using an algorithm
     • Algorithm is cipher
   • To make unintelligible
     • Cipher text
   • To anyone except those who are having the special knowledge
     • Key

5. What is Decryption?(2)

   • It is a process
   • Converting cipher text to plain text