Cryptography is the science of securing information and communication through techniques like encryption. The document discusses various cryptography concepts like encryption algorithms, symmetric and asymmetric key encryption, objectives of cryptography like confidentiality and integrity, and applications of encryption like web browsing, email, and video encryption. It also compares independent encryption with joint compression and encryption techniques for securing video data.

1. Ancy mariam babu
Vit university

2.  the need of multimedia secure
transmission
 need of more security
 What is cryptography…???

3.  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

4.  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.

7.  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

9.  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.

11.  Encryption is the
process of converting
plain text into cipher
text.
 Done by using
encryption
algorithms
 Key is used
 Two types:
-Asymmetric
-symmetric

14.  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

15.  Web browser encryption
 Email encryption
 Hard drive encryption
 Operating system protection

16.  Encryption on video
 Twotypes
- independent encryption
-joint compression and encryption

17.  Both encryption and compression done
seperatly
 Any compression standard can use for
compression
 For encryption, can use either
lightweight encription
or
heavyweight encryption

19.  Video encryption
technique
 Huge computation
overhead
 More secure

20.  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

21.  Video encryption
technique
 Faster and simple
 Less complexity
 Less time cosumption

22.  examples
 Rc6
 Idea
 hb2
 Present
 Tea

23.  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