Initially introduced in 2005, Open ID enables Single Sign On using a centralized identity provider.
With Open ID, you can create a single account with an ID and Password with an Identity Provider and then that provider confirms your identity at each place you have to authenticate by proving your identity.
In this mechanism, no other website ever gets to view your login credential except the identity provider itself.
However, nowadays, Open ID has become obsolete and OAuth and Open ID connect are the new popular standards of the day,
It is decentralized in nature unlike OAuth that provides centralized authorization.
In order to get an Open ID, the end-user needs to get himself registered with an Open ID Service provider.
Open ID was implemented in various tech giants like Google, Yahoo, Paypal, Zoho etc.
However, in due course of time, various security issues were reported in Open ID technology leading to its subsequent downfall. Attacks like “Data Type Confusion Logic Flaw”, Open ID request forgery, phishing and privacy issues were reported leading to vulnerable implementations.