Asymmetric encryption (public-key encryption) 

-          Encodes messages using two mathematically related numeric keys 

-          Public key: one key freely distributed to public 

·         Encrypt messages using encryption algorithm 

-          Private key: second key belongs to key owner 

·         Kept secret 

·         Decrypt all messages received 

ADVANTAGES 

 • A symmetric cryptosystem is faster. 

 • In Symmetric Cryptosystems, encrypted data can be transferred on the link even if there is a possibility that the data will be intercepted. Since there is no key transmiited with the data, the chances of data being decrypted are null. 

 • A symmetric cryptosystem uses password authentication to prove the receiver’s identity. 

 • A system only which possesses the secret key can decrypt a message. 

 

 DISADVANTAGES 

 • Symmetric cryptosystems have a problem of key transportation. The secret key is to be transmitted to the receiving system before the actual message is to be transmitted. Every means of electronic communication is insecure as it is impossible to guarantee that no one will be able to tap communication channels. So the only secure way of exchanging keys would be exchanging them personally. • Cannot provide digital signatures that cannot be repudiated