public class Vigenerecipher {
	    public static void main(String[] args) {
	        String key = "ncl";
	        String original = "newcastleuniversity";
	        String encripted = encrypt(original, key);
	        System.out.println(encripted);
	        System.out.println(decrypt(encripted, key));
	    }

	    static String encrypt(String text, final String key) {
	        String res = "";
	        text = text.toLowerCase();
	        char[] stringArray = text.toCharArray();
	        for (int i = 0, j = 0; i < text.length(); i++) {

	            if ((int)stringArray[i] < 97 || (int)stringArray[i] > 122) continue;
	            res += (char)(((int)stringArray[i] + key.charAt(j) - 2 * 'a') % 26 + 'a');
	            j = ++j % key.length();
	        }
	        return res;
	    }

	    static String decrypt(String text, final String key) {
	        String res = "";
	        text = text.toLowerCase();
	        for (int i = 0, j = 0; i < text.length(); i++) {
	            char c = text.charAt(i);
	            if (c < 97 || c > 122) continue;
	            res += (char)((c - key.charAt(j) + 26) % 26 + 'a');
	            j = ++j % key.length();
	        }
	        return res;
	    }

}