PHP的加密和解密程序方法

{ srand((double)microtime()*1000000); $encrypt_key=md5(rand(0,32000)); $ctr=0; $tmp=""; for($i=0;$i<strlen($txt);$i++) { if($ctr==strlen($encrypt_key))$ctr=0; $tmp.=substr($encrypt_key,$ctr,1). (substr($txt,$i,1)^substr($encrypt_key,$ctr,1)); $ctr++; } returnkeyED($tmp,$key); } functiondecrypt($txt,$key) { $txt=keyED($txt,$key); $tmp=""; for($i=0;$i<strlen($txt);$i++) { $md5=substr($txt,$i,1); $i++; $tmp.=(substr($txt,$i,1)^$md5); } return$tmp; } $string="HelloWorld!!!"; //encrypt$string,andstoreitin$enc_text $enc_text=encrypt($string,$key); //decrypttheencryptedtext$enc_text,andstoreitin$dec_text $dec_text=decrypt($enc_text,$key); print"Originaltext:$string<Br>\n"; print"Encryptedtext:$enc_text<Br>\n"; print"Decryptedtext:$dec_text<Br>\n"; ?>