An encryption processing system includes: an encryption data generation device, an encryption processing device, and a processing result utilization device. A first processor of the encryption data generation device is configured to perform preprocessing by generating encrypted data of homomorphic encryption corresponding to data obtained by multiplying plaintext data as a target by a power of a predetermined number of two or more. A second processor of the encryption processing device is configured to perform acquiring the encrypted data, and executing a processing on the encrypted data in an encrypted state to obtain a processing result in the encrypted state. A third processor of the processing result utilization device is configured to perform acquiring the processing result, and postprocessing by decrypting data of the processing result in the encrypted state and by dividing the decrypted data by the power of the predetermined number of two or more.