Table 6 Example key exchange scenario using ECDH and CA-based key derivation.

Alice

Generates (PrivateKey_A, PublicKey_A)

PrivateKey_A (secret)

Ready for exchange

Bob

Generates (PrivateKey_B, PublicKey_B)

PrivateKey_B (secret)

Ready for exchange

Alice \(\rightarrow\) Bob

Sends PublicKey_A to Bob

PublicKey_A (shared)

Bob receives Alice’s key

Bob \(\rightarrow\) Alice

Sends PublicKey_B to Alice

PublicKey_B (shared)

Alice receives Bob’s key

Alice

Computes SharedSecret = PrivateKey_A \(\times\) PublicKey_B

PrivateKey_A + PublicKey_B

Gets shared secret

Bob

Computes SharedSecret = PrivateKey_B \(\times\) PublicKey_A

PrivateKey_B + PublicKey_A

Gets same shared secret

Both

Generate CA_Key from shared secret

CA_Key (derived)

Ready for AES encryption