A5/1加密算法（java實現）

import java.util.Arrays;
import java.util.Scanner;


public class A5_1算法 {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner in = new Scanner(System.in);
		int X[] = new int[19];   //x寄存器  
		int Y[] = new int[22];   //y寄存器
		int Z[] = new int[23];	//z寄存器
		System.out.println("請輸入需要獲取多少位祕鑰流:");
		int w = in.nextInt();
		int []S = new int[w];  //開闢存儲指定w位祕鑰流的空間
		
		System.out.println("輸入初始寄存器X中的值:");
		for (int i = 0; i < X.length; i++) {
			X[i] = in.nextInt();
		}
		
		System.out.println("輸入初始寄存器Y中的值: ");
		for (int i = 0; i < Y.length; i++) {
			Y[i] = in.nextInt();
		}
		
		System.out.println("輸入初始寄存器Z中的值: ");
		for (int i = 0; i < Z.length; i++) {
			Z[i] = in.nextInt();
		}

		for (int i = 0; i < w; i++) {  //循環進行獲取w位祕鑰
			int M = Maxj(X[8],Y[10],Z[10]);  //進行投票,來決定處不處理X,Y,Z寄存器
			if (X[8]==M) {  //處理X寄存器
				int t = X[13]^X[16]^X[17]^X[18];
				Xleft(X);
				X[0] =  t;
			}
			if (Y[10]==M) {//處理y寄存器
				int t = Y[20]^Y[21];
				Yleft(Y);
				Y[0] =  t;
			}
			if (Z[10]==M) {//處理z寄存器
				int t = Z[7]^Z[20]^Z[21]^Z[22];
				Zleft(Z);
				Z[0] = t;
			}		
			S[i] = (X[18]^Y[21])^Z[22];  //保存生成的祕鑰位
			//System.out.println(X[18]^Y[21]^Z[22]);
		}
		
		System.out.println(w+"位祕鑰流爲：");
		System.out.println(Arrays.toString(S));
		
		System.out.println("X寄存器的內容爲：");
		System.out.println(Arrays.toString(X));
		
		System.out.println("Y寄存器的內容爲：");
		System.out.println(Arrays.toString(Y));
		
		System.out.println("Z寄存器的內容爲：");
		System.out.println(Arrays.toString(Z));
		System.out.println();

}
	
	/**
	 * x寄存器右移移函數
	 * @param x
	 */
	public static void Xleft(int[] x) {
		for (int i = x.length-1; i>0; i--) {
				x[i] = x[i-1];		
		}
	}
	
	/**
	 * y寄存器右移函數
	 * @param x
	 */
	public static void Yleft(int[] y) {
		for (int i = y.length-1; i>0; i--) {
			y[i] = y[i-1];		
		}
	}
	
	/**
	 * z寄存器右移函數
	 * @param x
	 */
	public static void Zleft(int[] z) {
		for (int i = z.length-1; i>0; i--) {
			z[i] = z[i-1];		
		}
	}

	/**
	 * 投票函數
	 * @param x
	 * @param y
	 * @param z
	 * @return
	 */
	public static int Maxj(int x, int y, int z) {
		int count = 0;
		if (x==1) {
			count++;
		}
		if (y==1) {
			count++;
		}
		if (z==1) {
			count++;
		}
		
		if (count>=2) {
			return 1;
		}else {
			return 0;
		}
	}
	
}