How to find Iphone Lost or stolen in iOS 13

The new function Find (in English) of iOS 13 and macOS Catalina will put all the iPhone and Mac in the world looking for a lost or stolen Apple device - even when the screen is off.

This security tool was released on Monday, June 3 during the inaugural conference of WWDC 2019; But in a call with Wired the firm of Cupertino detailed, step by step, how this feature works, according to Apple, will help to prevent a product from the apple is attractive to thieves.

Search in iOS 13 and macOS Catalina, this is how it works:
For Search to work, it is necessary for the user to have at least two Apple devices, either an iPhone or a Mac and use the same Apple account.
The devices generate a private key that is shared only between devices with the same account and is stored locally (Apple does not have this private key)
The devices generate a public key, which is encrypted and shared with other devices. This public key is constantly updated and re-sent (the public key is never repeated to prevent someone from using it to track your movements)
A lost (or stolen) device, even when in standby mode and without an Internet connection, will emit a signal via Bluetooth
Any iPhone, iPad or Mac, without owner interaction, can detect the lost device's signal, encrypt its location and send it to Apple's servers along with a hash (a type of encryption) that will be used to identify the lost device
The affected user takes another of his Apple devices (which has a copy of the private key and public key of the lost device)
That second device uses the hash of the lost device and Apple looks for its equal in the servers
Apple sends the location (encrypted) to the second device, which, thanks to having the private key, can remove the encryption and see the location of the lost device
Wired contacted Matthew Green, an expert in encryption and cryptography at Johns Hopkins University to comment on this new Apple encryption. "I have not seen anyone offer something like that to billions of people," Hopkins said. "The current technique is well known in the scientific scene, but implementing something like that would be very impressive."

Apple told Wired that the protocol could change before launching in macOS Catalina and iOS 13, operating systems that are already in the hands of developers but will reach the public until the fall of this year.