403613 Barcode Ticket System

Need a system to sell tickets online for events, concerts, festivals. Here is how the system should work: -Admin sets up ticket options, like price, dates, amount of tickets available per price -Buyer selects number of tickets to purchase, the system directs them to paypal to purchase tickets and returns them to a page to print tickets off. Each ticket gets a unique barcode. I am not set on type of barcode system but would like a QR code system if it is secure from being duplicated or changed. -Buyer prints tickets and brings them to the event. -Person at the door scans the barcode with barcode app for iphone or other smartphone barcode scanner that verifies the code is unique and valid, the door person selects "use ticket" which takes the ticket out of the system instantly so it can not be used again. -Person at the door sees the detailed information of the ticket purchased, like date of the event and the name of the event, person's name who purchased tickets, etc. -Buyer creates simple login username and password and the name of each person per ticket. -person at the door should have to enter a password to scan the barcodes and to select "use ticket" -person who purchased tickets should be able to use their login to check status of the ticket like date and title of event, how many tickets were purchased, and if the ticket is valid or used. I need this simple and easy to use. I figure a simple php/mysql database to store the info and admin can login to see all the tickets purchased and by who and for what event, day, etc.