Cryptography is the science of secret writing with the intention of keeping the data secret. Cryptography is classified into symmetric cryptography, asymmetric cryptography and hashing.

**Private Key:**

In Private key, the same key (secret key) is used for encryption and decryption. In this key is symmetric because the only key is copy or share by another party to decrypt the cipher text. It is faster than the public key cryptography.

**Public Key:**

In Public key, two keys are used one key is used for encryption and another key is used for decryption. One key (public key) is used for encrypt the plain text to convert it into cipher text and another key (private key) is used by receiver to decrypt the cipher text to read the message.

Now, we see the difference between them:

S.NO | Private Key | Public Key |
---|---|---|

1. | Private key is faster than public key. | It is slower than private key. |

2. | In this, the same key (secret key) and algorithm is used to encrypt and decrypt the message. | In public key cryptography, two keys are used, one key is used for encryption and while the other is used for decryption. |

3. | In private key cryptography, the key is kept as a secret. | In public key cryptography, one of the two keys is kept as a secret. |

4. | Private key is Symmetrical because there is only one key that is called secret key. | Public key is Asymmetrical because there are two types of key: private and public key. |

5. | In this cryptography, sender and receiver need to share the same key. | In this cryptography, sender and receiver does not need to share the same key. |

6. | In this cryptography, the key is private. | In this cryptography, public key can be public and private key is private. |