What Is Public Key Encryption ? Public Key Cryptography and SSL

What Is Public Key Encryption?

Public Encryption or public Cryptography is a method of encrypting the data with two different keys and making them one key the public key which is available for everyone and the other key is known as a private key. Data Encrypted with the public key that can only be decrypted by the private key. Public key Encryption is also known as the symmetric key. It is used for TLS/SSL which makes HTTPS for the website.

Cryptographic Key

The Cryptography key is a piece of information that is used for scrambling data that may help to appear data random; often string of number and larger number or letter. The unencrypted data is called as Plaintext and after that, the encryption algorithms use the key and encrypt the whole data on the other side the data decrypted and show plaintext.

For Example: If you Input data “vednam” and after encryption with key “*2696726281hj” and now you can read that data like “XYHTJLGR+*” which you think it is garbage data. However, after decrypting the same data you got plaintext “vednam”

Plaintext + key = Ciphertext

Vednam +  *2696726281hj = XYHTJLGR+*

Ciphertext + key = plaintext

XYHTJLGR+* + *2696726281hj = vednam

(The above example shows the perfect symmetric encryption methods where only one key is used.)

How Does Public Key Encryption Work?

Public key Encryption seems too difficult to initiate but a writer named “Panayiotis” writes a relatable story.

He says let’s imagine a trunk with a lock that two people, Bob and Alice, use to ship documents back and forth. A typical lock has only two states; locked and Unlocked. Anyone with a copy of the key can unlock the trunk if it’s locked and vice versa. When Bob locks the trunk and sends it to Alice, he knows that Alice can use her copy of the key to unlocking the trunk.

You must read to know the scenario of the symmetric cryptography activities. One secret key used both encrypting and decrypting and both sides of the conversation unlocked with the same key

The machine sending the data encrypts the document or file with the help of asymmetric key, then encrypts the symmetric key with the public key of the receiving computer.The receiving computer uses its private key to decode the symmetric key and after the document or file is decoded.

How does TLS/SSL use public key Encryption?

Public Key encryption is useful for establishing secure communications over the internet(Via HTTPS).A website that has SSL/TLS certificate which is shared publicly contains a public key and the private key is installed on the server.

TLS uses public-key cryptography to authenticate the identity of the originating server and to exchange data it usually generates the session keys. The exchange key algorithm ,such as RSA or Diffie-heliman,uses the public-private key pair to agree to the session keys basically used for symmetric encryption once the session is completed. The client and servers are able to agree upon new session keys for each communication session. Bad actors are unable to decrypt

Communications even if they identify or steal one of the session keys.