From my research, most of the blockchain application uses elliptical cryptography to create public key, private key, encrypt, decrypt and verify. But, in this application I use different approach. I use RSA algorithm.
RSA Boy has the ability to create private key, public key, encrypt, decrypt, sign and verify as well.
You can see how asymmetric cryptography works from the example I gave to the repository.
You can contribute by pull request in the following repository https://github.com/nitzaalfinas/RSABoy