It may be a very long time for the 3rd World. When their rules call for a "ticket" to enter, you had better have a paper ticket. I frankly don't see those folks getting up to date in the near future. And they are very self-important in immigration there. Anywhere, actually. The greatest risk is having to buy a return ticket in order to enter the country. Even with a local airline official trying to explain e-tickets to immigration, they would not accept one in Egypt.