doubi9999 2017-06-08 11:40
浏览 318
已采纳

PHP - 无论如何在PHP中加密/解密哈希? [关闭]

I'm interested to encrypt/decrpyt hash in PHP.

But as I know hash can be encoding only with md5, sha1, sha256.

However, is it possible to make encrypt/decrpyt in PHP by another hash like ripemd160, haval256,5 or ripemd256?

Thank

  • 写回答

2条回答 默认 最新

  • dongren4758 2017-06-08 13:10
    关注

    Hashing algorithms are not encryption algorithms. Hashing algorithms have the following principles:

    • Specific input produces always the same output
    • The input cannot be resolved based on the output
    • Any change to input will produce different output

    Technically the last one is not true, because you have limited amount of possible outputs but basically unlimited amount of possible inputs. Therefore there will be other inputs that produces the same output, but for strong hashing algorithms finding those collisions takes VERY long time as @delboy1978uk explained.

    MD5 is an example of a weak hashing algorithm that you should not use for secure hashes. Collision attacks against MD5 are cheap. On the other hand hashing algorithms in SHA2 family can be considered secure (take SHA256 for example).

    Encryption algorithms require a key or multiple keys to allow you to do decryption on the cipher text.

    The short answer to your questions is no.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 求差集那个函数有问题,有无佬可以解决
  • ¥15 【提问】基于Invest的水源涵养
  • ¥20 微信网友居然可以通过vx号找到我绑的手机号
  • ¥15 寻一个支付宝扫码远程授权登录的软件助手app
  • ¥15 解riccati方程组
  • ¥15 display:none;样式在嵌套结构中的已设置了display样式的元素上不起作用?
  • ¥15 使用rabbitMQ 消息队列作为url源进行多线程爬取时,总有几个url没有处理的问题。
  • ¥15 Ubuntu在安装序列比对软件STAR时出现报错如何解决
  • ¥50 树莓派安卓APK系统签名
  • ¥65 汇编语言除法溢出问题