Study on Application of Encryption Mask in Butterfly Algorithm of fast Fourier Transform

The rapid development of the IT industry has led to an increasing dependence on digital technologies, resulting in the need to process vast amounts of data on a scale previously unseen. In particular, since such data often includes sensitive personal and technical information, there is a growing demand for data security technologies to prevent hacking, replication, and ensure safe protection. In this paper, we propose an optimal encryption mask design method by leveraging the butterfly algorithm of the Fast Fourier Transform (FFT) to enable fast transmission and reception of two-dimensional image data. For data security, we develop phase-modulated Hadamard masks and bit-shifted masks. Additionally, we analyze the performance of the proposed encryption masks by calculating the correlation coefficient(CC) between the original, encrypted, and restored data.