Symmetric key cryptography systems use the same key for both to encrypt the plaintext and to decrypt the ciphertext. Symmetric key systems have the advantage of being simple and fast. However, the important factor to be considered is that the parties involved must exchange the key in a secured way.
In comparison to symmetric key, public key cryptography systems use
different keys to encrypt to plaintext and to decrypt the ciphertext.
Public key uses 2 different keys – a public key for encryption and
a private key for decryption. Using this encryption system, the public key can
be distributed in a non-secure way. The private key is never transmitted and is
only available at the recipient’s side. As the keys are different, the
decryption of the chipertext computationally is assumed to be not feasible
without the private key.
