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 ++; } return keyED( $tmp , $key ); } function decrypt( $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" ; ?>