$SK =$ Secret Key (aka. Private Key)
$PK =$ Public Key
# Initial Connection(s)
```sequence
Participant Node
Participant Coordinator
Note right of Coordinator: Generate CA:SK & CA:PK\n \nSigns CA:PK with CA:SK (CA:S)\n \nPublishes (CA:PK || CA:S) as CA:C
Note left of Node: Generate N:SK & N:PK
Node->Coordinator: Establishes connection
Coordinator->Node: Sends CA:PK
Note left of Node: Signs CA:PK with N:SK (N:CA:S)
Node->Coordinator: Sends N:PK, N:CA:S
Note right of Coordinator: Verify N:CA:S using N:PK\n \nThus proving the node\nhas N:SK via signing
Note right of Coordinator: Signs N:PK with CA:SK (N:CA:S)\n \n(N:PK || N:CA:S) becomes (N:C)\n \nSave N:C to certificate store\n \nThe "fingerprint" of\nN:C would be H(N:C)
Coordinator->Node: Sends N:C
Note left of Node: Save N:C for future use
```
# Subsequent Connection
### AKA "phase 2" or node-to-node
```sequence
Participant Node
Participant Coordinator
Node->Coordinator: Establishes connection
Coordinator->Node: Sends CA:PK\n(renamed to CO:PK to avoid confusion)
Note left of Node: Signs CO:PK with N:SK (N:CO:S)
Node->Coordinator: Sends N:C, N:CO:S
Note right of Coordinator: Lookup N:C in CRL\nby "fingerprint"
Note right of Coordinator: Verify N:C by splitting into\nN:PK && N:CA:S\n \nVerify N:CA:S using CA:PK from CA:C\n \nThus proving the cert\nis valid and the N:PK is real
Note right of Coordinator: Verify N:CO:S with N:PK\n from N:C\n \nThus proving that the\nnode has knowledge of N:SK
```