# Shared-key authentication

## Connection-oriented

<figure><img src="https://3490214077-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FAHT7avzIVwxfPJ4pkhhO%2Fuploads%2FsY5wazk2bE51VUkNmwoq%2F2024-04-21_16-52.png?alt=media&#x26;token=7ca5a5e2-6765-495b-97f7-a94cb0b0ed4c" alt=""><figcaption></figcaption></figure>

## Connection-less

<figure><img src="https://3490214077-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FAHT7avzIVwxfPJ4pkhhO%2Fuploads%2FCju4RAIOYHG9zSw3X8gS%2F2024-04-21_16-53.png?alt=media&#x26;token=671be373-a3f8-4ac1-9024-eda2d95c03fa" alt=""><figcaption></figcaption></figure>

## Issue

How to distribute $$K_{ab}$$ to all possible A-B pairs?
