A HOTEL DOOR KEY ON YOUR PHONE

THE number of hotels in the United States that have digital keys available rose from 9 percent in 2016 to 17 percent last year, according to a survey by the American Hotel and Lodging Association.

Marriott international, Hilton, MGM Resorts and Disney hotels are among the brands offering loyalty members the option of using digital keys in some properties.

Some, including Hilton and Marriott, only allow a single phone to receive a single key during a stay and other guests in the room receive RFID [radio frequency identification] card keys.

Like the card keys the digital keys can be used to access elevators, fitness centers, parking garages, and other common areas. Some mobile keys require the user to touch a button on their phone screen to unlock the door, while others require that the phone be held up to the lock.

Digital keys are hugely popular with travelers in some areas, like Silicon Valley, but an expert estimated that only about 10 percent of all hotel guests use them,over all.

''Every new technology generates a little fear,'' he said.

One of them who shied away during a recent trip was Lexi Galantino, 23, a San Francisco based software engineer who specializes in protecting privacy. Ms Galantino was set to try a digital key at a hotel in Kauai, Hawaii, in April, but as she was downloading the app , she opted instead for a card key.

''I was a little bit spooked by some of the security things,'' she said.

Last year, the Finnish Cybersecurity firm F-Security Corp, revealed that after thousands of hours of work it had found a flaw in an older model RFID-style digital hotel lock that could allow the hackers to create a speed master key.

It worked with Assa Abloy to patch that software, which was used in 42,000 properties in 166 countries. said Tomi Tuominen, of Helsinki, a researcher.

It will take years to know if other digital locking systems are secure, since there are many manufacturers using so many different technologies, he said. On top of that, there are potential vulnerabilities in the apps that are used to access the keys, and in guests phones themselves, he said.

Marriott International expects to expand the use of its Mobile Key technology from the 1,800  hotels that currently have it available in its Bonvoy program members to all of its 7,000 properties by the end of 2020, said a spokesman, John Wolf.

Hilton has installed Digital Key for Honors members at more than 4,250 of its 5,700 properties worldwide over the past five years, said Nigel Gleenie, a Hilton spokesman. There is no target date for completing  the rollout, he said.

''Tight now there is no chain that is not at least talking about it and trying to so something about,'' said Mr. Aznar of Assa Abloy.

The World Students Society thanks author Karen Schwartz.