A method and computer-readable storage medium for a computer system to perform an encryption scheme is disclosed that is capable of encrypting big data that includes complex data, including image data, sensor data, and text data, and supporting both symmetric and asymmetric-key handling. The encryption scheme uses double hashing using two different consecutively-applied hash functions. With double hashing, the encryption scheme eliminates the threat of known cryptanalysis attacks and provides a highly secure ciphering scheme. Also, the ciphertext header generated in the encryption scheme enables efficient cloud data sharing. A user can share the encrypted data later by re-encrypting the seed and sharing a new ciphertext header without the need of re-encrypting the data or changing the secret or private key. Thus, the encrypted data stays as is in the cloud, and only the seed is encrypted and shared as needed.