Encryption device, encryption method, decryption device, and decryption method

There is provided an encryption device including a data encryption unit configured to conduct encryption on the basis of a white box model in which at least a part of a plurality of round functions for sequentially conducting encryption processing on an input value is tabulated, and input and output values of the round function are recognizable from an outside. The plurality of round functions each have an encryption function that is tabulated and encrypts an input value in a black box model in which input and output values are recognizable from the outside and an intermediate value is not recognizable from the outside.