默认登录凭据，特别是当是admin/root和密码时。

我所见过的最糟糕的是信用卡、个人识别码和姓名以纯文本形式存储。我差点心脏病发作了。

有一家银行通过其网站提供一些服务。开发人员考虑了任何作为整个系统的有效用户登录的人，他们使用URL来识别账号，因此只需更改URL上的ID，就可以查看其他账户的余额。

对于认为身份验证和授权是一回事的web开发人员来说，这是非常糟糕的。

此外，银行不通过其网站转账也很好，否则有些人会很富有;-)

测试一些银行柜员软件后，我打电话给技术部安排了一次拨号IP会话。“您想连接到哪个系统，生产系统还是测试系统?”

真实的故事。

一些验证码是这样的:

public bool charsEquals(char[] input, char[] txt)
{
    for (int i = 0; i < Math.min(input.length; txt.length); ++i)
    {
        if (input[i] != txt[i]) return false;
    }
    return true;
}

像这样使用它:

if (charsEquals(inputPassword, requestedPassword))

看了YouTube上关于Tux和比尔·盖茨之战的搞笑视频后，我开始思考这个问题。当Tux没有密码进入微软大楼时。

I was going to earn my credit with the supervisor for my quite advanced graphics program at a SunOS / Solaris with instant messaging enabled where with zephyr.vars or whatever it was called you could make an image appear on your listed friend's screen like if you alowed me I could just send you an image that appeared on your display. While I was demoing the program I had written so that the supervisor could give me credit for it, one of my friends sitting close or in the next room made the photo big-mama.xxx appear on my screen. There was never any discussion or penalty because of the incident and I got credit for the project that for ½ second seemed like it was programmed to display big-mama.xxx instead of solving the problem. (Earlier) I updated perl scripts and waited for sysadmin to reflect the changes to ouside the FW. Then the database was gone and it was not a bug it was a feature since the data was stored with the source and therefore updating the source blanked the persistence.

物理访问或模拟登录提示或登录屏幕是另外两种困难的情况，不需要过多的算法技术，很容易理解物理访问提供了许多可能性，模拟登录提示是您可以在许多不同类型的计算机和环境上进行的事情。