本次的FEAL8轮叠代要求将64位的密文C与64位的密钥K经过要设计的解密程序运行得到所需的64位的明文P。由于2进制输入输出的位数太长不方便，再程序的数据运算中大量用上16进制。在数据的运算过程中又常常把输入的数据平均分成等份，因此在数据处理上用上数组形式。FEAL算法的三个基本运算函数是整个程序的重心，程序的密钥处理和解密过程都将以这三个运算函数为中心，因此，程序的设计以S函数 函数和 f函数来展开，再由主函数编写时调用三个函数。-the FEAL8 round of the iterative requirements of the dense 64-C and 64 K after the key to the solution design running close access to the 64 P explicit. As the two-band input and output of the median long inconvenient, and then process the data using a large number of computations 16 band. Operational data in the process often imported data divided into equal portions, in data processing using an array form. FEAL algorithm three basic computing function is the focus of the whole process, Key handling procedures and decryption process of the three operations will function as the center, therefore, procedures designed to S Function and f function to commence further prepared by the main function calls the three functions.