Symmetric Cryptography, Asymmetric Cryptography and PKI (LEVEL : Beginner) - PART-2

 Symmetric cryptography:

Only one key is being used for encryption& decryption in symmetric cryptosystem,

The key which is used to encrypt some content, same key must be used to decrypt the encrypted content.

Let’s discuss a scenario where User1 wants to have confidential conversation with User2 using symmetric encryption. The encrypted conversation can only be started between them only if both the user has same symmetric key. In this case User1 has to generate and share the key with the User2. After sharing the key, User1 encrypts message & send it to user2, user2 decrypts the message to read it using the shared key. 

As encrypted conversation can only start after key is shared. But Key sharing itself takes place in unencrypted form. User1 has to share the key with User2 in unencrypted form, and there is a possibility of compromising the secret key during transition at the time of sharing.

Advantages:

·         Less Process consuming

Disadvantages:

·         Problem with key sharing

·         Vulnerable to MITM attack.

·         Vulnerable to Brute force attack.