## Private Key

- Private key is the technique that uses a single shared key (secret key) to encrypt and decrypt the message.
- It is also referred to as symmetric key encryption. It is because the same secret key is used in bidirectional communication.
- In private key cryptography, the key is kept as a secret.
- Stored in authorized devices and non-public-facing servers.
- The private key is kept secret and not public to anyone apart from the sender and receiver.
- A private key is used in the case of symmetric key cryptography wherein one single key is used for transmission between two parties.
- The main purpose of the secret key algorithm is to transmit the bulk data.
- It is faster as it uses a single key for encryption and decryption.
- In private key, the same key (secret key) and algorithm is used to encrypt and decrypt the message.
- In this cryptography, sender and receiver need to share the same key.
- There is a possibility of losing the key that renders the system void.
- Private key cryptography checks the speed, reliability, and security of the system.
- The private key is to be shared between two parties.

## Public Key

- Public key is the technique that uses two different keys for encryption and decryption.
- It is also referred to as Asymmetric key encryption.
- In public key cryptography, one of the two keys is kept as a secret.
- Stored inside the digital certificates, outgoing emails, and executables.
- The public key is free to use and the private key is kept secret only.
- In the case of a public key mechanism, there are two different keys used for the transmission. Which public-key is open for everyone to see and the private key is available only between the sender and the receiver.
- The main purpose of the public key algorithm is to share the keys securely.
- It is slower as it uses two different keys; both keys are related to each other through the complicated mathematical process.
- In public key cryptography, two keys are used, one key is used for encryption and while the other is used for decryption.
- In this cryptography, sender and receiver does not need to share the same key.
- There is a less possibility of key loss, as the key held publicly.
- The public key testing has a long-term view as Private key cryptography, it checks the speed, reliability, load and security of the system.
- The public key can be used by anyone but the private key is to be shared between two parties only.

## Private Key vs Public Key

BASIS OF COMPARISON | PRIVATE KEY | PUBLIC KEY |

Description | Private key is the technique that uses a single shared key (secret key) to encrypt and decrypt the message. | Public key is the technique that uses two different keys for encryption and decryption. |

Alternative Name | It is also referred to as symmetric key encryption. | It is also referred to as Asymmetric key encryption |

Cryptography | 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. |

Storage | Stored in authorized devices and non-public-facing servers. | Stored inside the digital certificates, outgoing emails, and executables. |

Usage | The private key is kept secret and not public to anyone apart from the sender and receiver. | The public key is free to use and the private key is kept secret only. |

Application | A private key is used in the case of symmetric key cryptography wherein one single key is used for transmission between two parties. | In the case of a public key mechanism, there are two different keys used for the transmission. |

Purpose | The main purpose of the secret key algorithm is to transmit the bulk data. | The main purpose of the public key algorithm is to share the keys securely. |

Efficiency | It is faster as it uses a single key for encryption and decryption. | It is slower as it uses two different keys; both keys are related to each other through the complicated mathematical process. |

Number of Keys | In private key, 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. |

Sender And Receiver | 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. |

Key Loss | There is a possibility of losing the key that renders the system void. | There is a less possibility of key loss, as the key held publicly. |

Functionality | Private key cryptography checks the speed, reliability, and security of the system | Public key checks Load testing checks the sustainability of the system. |