最简单的加密当然是混淆了. 任何一个字节,通过两次异或可以还原, 那么用这个原理就可以双方约定一组约定的字节序列进行混淆了

好了, 直接贴几个语言的实现

第一个luajit

local bit = require 'bit'

local function xor_encode(input, key)
	assert(#key > 0)
	--为了便于计算,这里使用0开始循环,由于lua语言的差异(末尾是闭区间), 所以减一
	local input_count, key_count = #input, #key
	local ret = ''
	for i = 1, input_count do
		local a = string.byte(input, i)
		local j = i%key_count
		local e = string.byte(key, j == 0 and key_count or j)
		local v =  bit.bxor(a, e)
		ret = ret .. string.char(v)
	end
	return ret
end


local t = xor_encode('hello!', 'ab')
print(xor_encode(t, 'ab'))

　贴个dart版本的

import 'dart:convert' show utf8;

// 将字符加密
List<int> xorEncode(String input,String key) {
  
  final keyLen = key.length;
  final count = input.length;
  
  List<int> inputBytes = utf8.encode(input);
  List<int> keyBytes = utf8.encode(key);
  
  List<int> ret = [];
  for(var i=0; i<count; i++){
    final j = i%keyLen;
    final v = inputBytes[i] ^ keyBytes[j];
    ret.add(v);
    
  }
  return ret;
}

// 将加密后的东西解开
String xorDecode(List<int> inputBytes, String key) {
  List<int> keyBytes = utf8.encode(key);
  
  final keyLen = key.length;
  final count = inputBytes.length;
  
  for(var i=0; i<count; i++){
    final j = i%keyLen;
    inputBytes[i] ^=  keyBytes[j];
  }
  
  return utf8.decode(inputBytes);
}

void main() async {
  final input = "hello!";
  final key = "ab";
  final encRet = xorEncode(input, key);
  final decRet = xorDecode(encRet, key);
  print(decRet);
}

　　再来个js版本的

// 编码
function xorEncode(input, key) {
    let len = input.length
    let keyLen = key.length
    let results = []
    for(var i = 0; i < len; i++) {
        let j = i%keyLen
        let v = input[i].charCodeAt() ^ key[j].charCodeAt()
        results.push(v)
    }
    return results
}

// 解码
function xorDecode(input, key) {
    let len = input.length
    let keyLen = key.length
    let results = ''
    for(var i = 0; i < len; i++) {
        let j = i%keyLen
        let v = input[i] ^ key[j].charCodeAt()
        results += String.fromCharCode(v)
    }
    return results
}

let e = xorEncode('hello~!', 'ab')
console.log(xorDecode(e, 'ab'))