Encrypt given data using camellia-128-ofb cipher algo. Camellia in 128-bit key size with OFB (Output Feedback) mode, which turns a block cipher into a stream cipher using a feedback loop. OFB mode for Camellia was designed as a secure alternative to other modes like ECB, making it more resilient to certain types of cryptographic attacks. OFB is generally secure but has limitations in error propagation and key reuse vulnerabilities. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.