S-盒是许多分组密码算法中唯一的非线性部件,它的密码强度决定了整个密码算法的安全强度。介绍了分组密码中S-盒的设计准则与构造方法,对S-盒设计中纠错码原理与方法进行讨论,最后给出了现代分组密码中广泛应用于S-盒设计的仿射逆函数所具有的密码特性,并证明了仿射逆函数在代数结构上存在分量函数的线性等价性。 The S-box is the only non-linear component of many block cipher algorithms, whose cipher strength determines the security strength of the cipher algorithm. The design criteria and construction method of S-box in block cipher are introduced. The principle and method of error-correcting code in S-box design are discussed. Finally, an affine inverse function which is widely used in S-box design in modern block cipher is given. Has the cryptographic properties and proves the linear equivalence of the affine functions in the algebraic structure.