Abstract: Partially homomorphic encryption systems may be transformed into fully homomorphic encryption systems. Input plaintext data are transformed into modified plaintext data using a prime number operation and the modified plaintext data is then encrypted using any number of conventional encryption schemes. Desired computations on the encrypted data are transformed into homomorphic operations, based on the nature of the encryption format, and the homomorphic operations are applied to yield manipulated encrypted data. The manipulated encrypted data may be decrypted and the decrypted plaintext data may be modified into final, output plaintext data using a similar prime number operation as applied during encryption.