The idea of the Asymmetric Cryptography is completely different than the Symmetric Cryptography, but slightly identical. They are identical in the term of exchanging data (hidden messages). However, they different in the way the key is exchanged. The Asymmetric Algorithm or the (Public-key) is a Cryptography technique that allows many parties to send a message, but only one who has the access to these messages.
The principle of the Asymmetric Cryptography is to have two different keys. The first key is to encrypt, which is publicly defined usually. While, the second key is to decrypt, which kept private. For example, think of the mailbox principle, where everyone can drop a letter (encrypt the message via the public key); while only the mailman has the key to open the box (private key). Note: We can have multiple public key, but only one private key to achieve more security on this technique. See the figure below for more details:
This figure above shows the following:
- The users deposit (encrypts) a message with their public-key (Kpub).
- Only the Mailman has the private-key (Kpr) to retrieve (decrypt) the message.
Remember: Encryption is done via the public-key; while Decryption via the private-key.