Encrypt given data using chacha20 cipher algo. ChaCha20 is a stream cipher that uses a 256-bit key and a 64-bit nonce to produce a keystream for encrypting data. ChaCha20 was designed by Daniel J. Bernstein in 2008 as a more secure alternative to the Salsa20 cipher. ChaCha20 is considered very secure and is widely used in modern cryptographic protocols, including TLS and VPNs. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.