playfair.java

古典密码学的程序实现

/*
*Playfair加密算法
*用于补全的字母为q(q若不行则为z)
*由于补全用字母有随机性，且加密时i,j不分，所以解密后的明文尚需手动调整部分字母
*key = richard 因为有2个 'r' ,所以实际用的key 是 'richad'
*不区分大小写，密文一律大写
*/
public class Playfair
{
	char key[][] = {{'R','I','C','H','A'},{'D','B','E','F','G'},{'K','L','M','N','O'},{'P','Q','S','T','U'},{'V','W','X','Y','Z'}};
	public String getCipher(String message)
	{
		
	}
	public String getMessage(String cipher)
	{
	
	}
	public int[] iniString(String str)
	{
		String upStr = str.toUpperCase();
		char[] chars = upStr.toCharArray();
		int len = chars.length;
		int numOfChar = 0;
		for (int i=0;i<len ;i++ )//统计有多少个字母
		{
			if(Character.isLetter(chars[i]))
				numOfChar++;
		}
		int res[] = new int[numOfChar];
		int k=0;
		for (int j=0;j<len;j++ )//对整型数组赋值
		{
			if(Character.isLetter(chars[j]))
			{
				if ((int)chars[j]>=74)
				{
					res[k] = (int)chars[j] - 66;
				}
				else
				{
					res[k] = (int)chars[j] - 65;
				}
				k++;
			}
		}
		List<int> intList = new LinkedList<int>();
		int index = 1;
		intList.add(res[0]);
		while(index<res.length)
		{
			if (res[index] != intList.getLast())
			{
				intList.add(res[index]);
				index++;
			}
			else
			{
				if(intList.getLast != )
				iniList.add
			}
		}
	}
}