Imagine bypassing the front desk during your next hotel stay and entering your pre-booked hotel room with a tap of your smartphone. That will be a reality this week at several Starwood Hotels around the world.

The chain is to launch on Wednesday SPG Keyless, a program that allows travelers to check in and unlock their hotel rooms with a smartphone app, at 10 of its Aloft, Element and W hotels in Cancun, Mexico; Beijing; Singapore; Hong Kong; New York; Los Angeles, and Doha, Qatar. Starwood plans to expand the service to 30,000 rooms at 150 of its hotels around the world by early next year.

"Guests want this because it makes their lives simpler," Mark Vondrasek, who oversees the loyalty program and digital initiatives for Starwood, told the Associated Press. "The ability to go right to your room gives them back time."

Rival chain Hilton Worldwide will roll out a similar service by the end of 2015 at some of its Hilton, Waldorf Astoria, Conrad and Canopy properties in the United States.

"Travelers can use their smartphones as boarding passes to get to their seats on an airplane, so it is only natural that they will want to use them as a way to enter their hotel rooms,” Hilton CEO Christopher Nassetta said in July. “We have spent the past few years testing a number of different options to make this vision a reality, and we are developing proprietary technology that is safe and reliable for our guests to use, and cost-effective for our hotels to install."

These mobile apps employ Bluetooth technology to activate a smartphone as a room key. When guests check in using the app, the hotel receives the information and sends the room number back to the app, along with the app-as-key activation.

Of course, security is a major concern in the use of such apps. Selva Selvaratnam, chief technology officer of HID Global, the company behind the app’s security system, assured the BBC the app uses an encrypted secure channel to prevent thieves and others from abusing the tool.

And several safeguards are in place, Starwood officials said. For example, the SPG Keyless app will only unlock a room if the phone is actually touching a pad on the outside of a room door. This system was put in place to avoid accidental unlockings.

But not all experts are convinced. Alan Woodward, a professor of computing at the University of Surrey in the U.K. told the BBC nothing "is 100 percent secure, and once this technology is in widespread use, it will make a very tasty target for hackers."

"It may be more secure than a standard hotel swipe card lock but use of strong security features such as AES encryption and 'rotating keys' does not mean someone won't find an alternate way in,” Woodward said. “They will need to watch, learn and adapt if they are to keep their guests secure."