现在很多网站在身份登录、文章发表等地方都加上了图片认证码用来防止恶意程序的攻击，

取得了很大的效果，我也先后用过3个版本的图片认证码程序，最新的版本可以随机产生杂点，

并且可以进行颜色设置，本以为这样便绝对安全了，可是突然发现，

目前的很多认证码程序并不安全，

仔细研究一下就会发现不少漏洞，所以试着拿3721的来做一下，JAVA版本-many websites log, the article was published with other parts of the picture authentication codes used to prevent malicious attacks and has achieved great results. I have also used three versions of the pictures authentication code procedures, the latest version can generate random miscellaneous, and color can be set up, the thinking that it would be absolutely safe, but suddenly discovered, many of the current procedures for authentication code is not security, a closer look reveals many loopholes, So try to do with the 3,721 that Java version