the need of multimedia secure transmission need of more security What is 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
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.
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
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.
Encryption is the process of converting plain text into cipher text. Done by using encryption algorithms Key is used Two types: -Asymmetric -symmetric
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
Web browser encryption Email encryption Hard drive encryption Operating system protection
Encryption on video Twotypes - independent encryption -joint compression and encryption
Both encryption and compression done seperatly Any compression standard can use for compression For encryption, can use either lightweight encription or heavyweight encryption
Video encryption technique Huge computation overhead More secure
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
Video encryption technique Faster and simple Less complexity Less time cosumption
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