SECD
OFTP2 secure-authentication phase command, RFC 5024.
Definition
When secure authentication is negotiated in SSID, OFTP2 adds a challenge exchange: the initiator answers an encrypted challenge with AURP. SECD reverses the direction so the partner can issue its own challenge, achieving mutual authentication before any file transfer begins.
Origin
Defined in RFC 5024 §4.1 and §5.3 (ODETTE File Transfer Protocol 2), maintained by Odette International.
Example in context
Initiator → AUCH (challenge); responder → AURP; SECD → the responder now issues its own AUCH