dots myList row bit img char xor result dots2 key dots 54, 73, 65, 34, 20, 8 key = 123 xor 0, 0, 0, 0, 0, 0 result 0, 0, 0, 0, 0, 0 '平文', dots i len(dots) xor i dots[i] ^ key '暗号化', xor i len(dots) result i xor[i] ^ key '復号', result []