# Cryptography - Public Key Encryption

### Table of Contents

## About

Public Key Encryption (PKE) is the encryption method of the public key cryptography that ensure that a communication is kept confidential (secrecy) during transit.

## Scheme

Public Key encryption procedure:

- the
**recipient's public key**encrypts the message (the sender of the message do it and he cannot decrypt the encrypted message) - the encrypted message is transmitted electronically to the receiver.
- the
**recipient's private key**decrypts the message (the receiver do it. Only the person who holds the matching private key can read the message).

An analogy to public key encryption is that of a locked mail box..

- The public key is the mail slot. Anyone knowing the street address can go to the door and drop a written message.
- The private key is the key. Only the person who possesses the key can open the mailbox and read the message.

A keypair is often used to exchange an on-the-fly symmetric key, which will only be used for the current session.