Table 3 Notation and respective description for edge server authentication to main server

id_{es, k}

ID of the k_th edge server

id_ms

ID of the main server

pwd_es,k

Password of k_th edge server

TS_mss

Timestamp when computing MSS (Main

Server’s Secret)

K_{pr, ms}

Private key of main server

K_{pb, ms}

Public key of main server

K_pr,es

Private key of edge server

K_pb,es

Public key of edge server

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Concatenation

N1

Nonce