Data encryption and decryption using public and private key by openssl.

Firstly, need to install openssl in your device. For check openssl go to Terminal or PowerShell and type

openssl
If you have openssl then
mkdir keys
cd keys
openssl genrsa -des3 -out private.pem 4096

4096 is actually byte of private key. if you want to change this value, you can change it.

Need to write a pass phrase. Pass phrase must be at-least 2 character.
openssl rsa -in private.pem -out public.pem -outform PEM -pubout
Again write a same pass phrase

Finally Run this code.