用维吉利亚密码的方法，以ART（不区分大小写）为密钥对任意给定的字母进行加密。加密方法为：将字母a,b,c…z 对应数字0,1,2……25。明文字母m，密文c，密钥k，c=m+ki mod 26 (i=1,2,3)。-Password with the Virginia approach to ART (not case sensitive) as the key for any given letter is encrypted. Encryption methods are: the letters a, b, c ... z corresponds to the number 0,1,2 ... ... 25. Plaintext letter m, the ciphertext c, the key k, c = m+ ki mod 26 (i = 1,2,3).