**Difference between DES and AES**

- DES was originally designed to run in specialized hardware and is considered “computationally expensive” on general-purpose processors. AES was designed to run efficiently on a variety of processors, including general-purpose ones.
- AES is more secure when compared to DES as it uses large blocks for encryption and the algorithm is relatively complicated than AES. Possible number of AES 128-bit keys are 10
^{21 }times greater than DES 56-bit keys, hence it is found that a machine that could recover a DES key in a second (I.e. try 2^{55}keys per second) , it takes 149 trillion years to crack a 128-bit AES key.

## Asymmetric or Public Key Cryptography

“Public-key cryptography” is one of the most reliable and secure cryptography algorithm. It is also known as asymmetric. In public-key cryptography, user has a pair of keys known as public key and private key, of which one is used for encryption and other the other one for decryption. The keys are related mathematically, but to derive either of the keys using the other one is practically impossible, hence the public key is distributed and is accessible to all the users and the private key is not revealed. If a sender wants to send a message he will encrypt the message with the recipient’s public key which is accessible widely among the internet and sends it to the recipient, at the other side the recipient will decrypt the message with his secret key.

This Project Paper is written & submitted by **Deepak V****.**