You can enable this protocol when you need to pair your phone
with another user's phone. Because manual exchange is difficult.
Now I don't understand what problem you are trying to solve. If the two
phones are physically close to each other, we have existing short-range
data exchange systems such as infrared and Bluetooth that work fine. If
the two parties already know each other, there is presumably some existing
communication path such as e-mail they can use to exchange credentials.
On the other hand, if you are trying to solve the introduction problem,
how to establish a channel between two people who don't already know each
other, that's a famous swamp, and taking a couple of phones into the
swamp doesn't change the issues.
John Levine, johnl(_at_)iecc(_dot_)com, Primary Perpetrator of "The Internet for
Information Superhighwayman wanna-be, http://www.johnlevine.com, ex-Mayor
"More Wiener schnitzel, please", said Tom, revealingly.
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