The Application layer generally encounters problems
pertaining to data security during transmission. To protect data from
unauthorized access and hacking during transmission, the Application layer
applies various encryption techniques. The types of encryption techniques are
private key encryption and public key encryption.
To implement private key encryption, the Network layer uses
algorithms such as Data Encryption Standard (DES). In the DES algorithm, the
data contained in the data packets is encrypted in blocks of 64 bits of cipher
data using a 56-bit key. The sender and the receiver agree on this 56-bit key
before transmitting the data packets. After the data is transmitted, the
receiver uses this 56-bit key to decrypt the encrypted data.
Similarly, to implement public key encryption, the Network
layer uses the Rivest-Shamir-Adleman (RSA) algorithm. Using the RSA algorithm,
the sender and receiver use a pair of keys to encrypt and decrypt the data
contained in the data packets. The key pair contains a public key and a private
key. The sender uses the public key of the key pair to encrypt the data, and the
receiver uses the private key to decrypt the data.