Back-channel Communication is a communication
between two or more parties which happen outside the observation of other parties involved with a protocol
Back-channel Communication in OAuth 2.0
is typically used to describe communications between the components where the user-agent
(browser) in not involved.
The OAuth Client will communication with the Authorization Server and Resource Server without the participation of the Resource Owner.
Likewise, there is communication between the Authorization Server and Resource Server without the participation of the Resource Owner or the OAuth Client
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