You to prevent site hacking by 'pirates' ?

Hi everyone.. I would know what did you think of my method to prevent 'piracy'.. I do like this : - A Session is made for each user In the session, put 2 value : a flag "userlogged" and the userId - In a cookie, I put the session Id and an unique crypted value. When user go on private parts of the site, I check the session, the cookie and database fields for the user.. The crypted data contains some user values (the encryption is done with mcrypt lib). Is it a good way or is there a better way (without SSL)... ? Regards, P.E. Baroiller