**Cryptography: **

Encryption is also referred as the cipher text; it is nothing but the process of converting some information into unreadable format to get protected from the unauthorized users. The text that is encrypted can be decrypted into readable format using a secret key. This process can also be referred as enciphering when the information is converted into unintelligible format using the translation tables and algorithms. The process of converting the information is also called as reversible translation. This cipher text which is converted into unreadable format is again re-converted into plain text to make it readable and this process is called as decryption or deciphering. Cryptographic systems are divided into symmetric key systems, in other words it is described as “the systems of cryptography are broadly classified into symmetric key systems”.

In a system if information is to be shared between the sender and the receiver then the process of encryption and decryption of the information is done by using a single key that known to both the sender and the receiver. The sender of the message uses the private key and the public key whereas the receiver uses the private key alone.

The process of encryption and decryption is done based on the algorithms and so appropriate algorithms are required for these processes. The sender uses a key to encrypt a plain text into unreadable format or chipper text. Then the receiver should use the same key used by the sender to decrypt the encrypted text to convert into plain text again.

This process of encrypting and decrypting is done using an algorithm called “symmetric key crypto graphic algorithm”. The best examples for symmetric key encryption are blowfish and data encryption standard (DES). The encrypted public key algorithm in the conversion of plain text, in this process the sender uses the public key to encrypt the plain text into cipher text and that text when received by the receiver then a private key owned particularly is used to decrypt the cipher text into plain text. There are some examples for the public key encryption algorithms and they are Elliptic Curve Cryptograph (ECC) and RSA. Cryptography plays a major role in security issues of multicasting.

This Paper is written & submitted by **Vamshidhar A.**