If you have:

• a website that allows users to create accounts
• a messaging platform
• any other type of service that may require users to prove their online identity

Then you may be interested in supporting decentralized identity proofs as they allow your users to securely prove their identity across services. Let's look at some examples:

• Alice and Bob have been talking for years on service A. Alice already has an account on service B. Bob wants to move to service B as well. A simple decentralized proof confirms that the person who is known as Alice on service A is also known as Alice on service B. Bob can safely move to service B and talk to Alice without having to meet in person to confirm their accounts.
• Alice has received a friend request from Bob29 on service C. Is this the same Bob from service A or not? A simple decentralized proof confirms that the person who is known as Bob on platform A is also known as Bob29 on service C. Turns out 28 Bobs were already using service C.
• Alice sends a cryptocurrency request to Bob. Is this a legit request? A simple decentralized proof tells Bob that that wallet is not owned by Alice. Bob knows something is up and does not transfer the money to the imposter.

The internet could be a slightly safer place if your service allowed your users to prove their identity. All the service needs to do is make a JSON file available with basic details about the user and set the correct CORS headers.

The documentation on what is precisely required is provided by the original creator of decentralized OpenPGP identity proofs.