Org.BouncyCastle.Crypto.Agreement.X448Agreement
X448 (RFC 7748) Diffie-Hellman raw agreement. Init takes the local
X448PrivateKeyParameters; CalculateAgreement
writes the 56-byte shared secret derived against the peer's
X448PublicKeyParameters.
Length in bytes of the shared secret produced by the agreement (56).
public X448Agreement()
Perform the agreement against publicKey and write the shared secret into
buf starting at off.
Span-based overload of CalculateAgreement.
Capture the local private key used for subsequent agreements.