Encryption

 Encryption is a text masking technique , derived from military use , which transforms in such a way that it may be correctly read only with a special password called key . It uses two key’s a public key for encrypting , usually known only to one computer or person , and a private key for decrypting , usually known by all the computers or people which legitimately may read the information . the size of these keys , and thus the difficulty to be guessed , is expressed in bits , with 128 bite being the typically most secure size used .

·       The two following schemas illustrates how B , C and D can send secret messages using A’s public key .

·       The sent messages are encrypted and later decrypted by A with his private key . In case somebody intercept a message , he is unable to decrypt it correctly since he does not have A’s private key , which is know only to A . Even when somebody uses the public key to decrypt , it does not work . 



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