cryptography and encryption
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CRYPTOGRAPHY AND ENCRYPTION
Ancy mariam babuVit university
INTRODUCTION the need of multimedia secure
transmission need of more security What is cryptography…???
CRYPTOGRAPHY CRYPTOGRAPHY IS THE
SCIENCE OF INFORMATION SECURITY
The word is derived from greek kryptos means hidden
Cryptography includes the techniques such as microdotes, merging words with images, other ways to hide information in storage or transit
Objectives of cryptography are
confidentiality
integrity
authentication
COMPONENTS OF CRYPTOGRAPHY
Encryption : it is the process of converting a plain text into (unrecognizable) cipher text.
For strong encryption: two attributes -confusion -diffussion Decryption: it is the process of changing
back the cipher text to plain text.
COMPONENTS OF CRYPTOGRAPHY
CATEGORIES OF CRYPTOGRAPHY
SYMMETRIC KEY CRYPTOGRAPHY
A single common key is used for encode and decode of messages
Both sender and receiver must know the common key
The common key need to be exchange before hand by some other secure method
Symmetric key encryption is fast and simple But the key management is impractical
SYMMETRIC KEY CRYPTOGRAPHY
ASSYMETRIC KEY CRYPTOGRAPHY
Two different key is used for encryption and decryption
Public key is used for encryption and private key is used for decryption
Each user has a public key and corresponding private key.
ASSYMETRIC KEY CRYPTOGRAPHY
ENCRYPTION… Encryption is the
process of converting plain text into cipher text.
Done by using encryption algorithms
Key is used Two types:
-Asymmetric
-symmetric
ASYMMETRIC ENCRYPTION
SYMMETRIC ENCRYPTION
WHY USE ENCRYPTION Authentication
-protects personal data such as passwords Privacy
-provides for confidentiality of private information
Integraty
-ensures that a document or file not has been altered.
Accountability
- prevents denial or plagarism
EXAMPLES OF ENCRYPTION
Web browser encryption Email encryption Hard drive encryption Operating system protection
VIDEO ENCRYPTION Encryption on video Twotypes
- independent encryption
-joint compression and encryption
INDEPENDENT ENCRYPTION
Both encryption and compression done seperatly
Any compression standard can use for compression
For encryption, can use either lightweight encription or heavyweight encryption
INDEPENDENT ENCRYPTION
HEAVY WEIGHT ENCRYPTION
Video encryption technique
Huge computation overhead
More secure
HEAVYWEIGHT ENCRYPTION TECHNIQUES Examples Des:
- data encryption standard for electronic encryption
-short key length and symmetric key block cipher
Aes:
-advanced encryption algorithm
- symmetric key encryption Rsa:
-public key scheme
- difficulty for factoring large number
-secure
LIGHTWEIGHT ENCRYPTION
Video encryption technique
Faster and simple Less complexity Less time cosumption
LIGHTWEIGHT ENCRYPTION TECHNIQUES examples Rc6 Idea hb2 Present Tea
JOINT COMPRESSION AND ENCRYPTION TECHNIQUE
Both encryption and compression integrates as a single step
System obtain multiple level of security Exaples
1.vea
2.rvea Two types
1.compression before encryption
2. compression after encryption
COMPRESSION BEFORE ENCRYPTION
COMPRESSION AFTER ENCRYPTION