F18-ND: Yes
Rationale
A bounded staged-pull witness carries the same named signed Data from producer A through caches B and C to final requester D. First, a local requester at B solicits the item from A; B admits the returning Data. Disconnect A-B. During B-C contact, a local requester at C asks for the same name; B serves its CS and C admits the returned Data. Disconnect B-C. D subsequently requests it from C. There is never an A-to-D path. Forwarder lookup, cache-hit response and solicited-Data insertion compose this relay-to-relay transfer without an application mailbox or new wire protocol. This is demand-triggered cache forwarding, not autonomous push, custody transfer or guaranteed delivery. Keep both caches alive, provision the name/trust/active faces, ensure capacity and bounded freshness, and use new Interest nonces. Cache eviction, absent requests or restart can defeat the witness.
Assessment method
Primary-source control-flow analysis and bounded composition inference; no protocol execution
Source context
NFD 24.07 forwarding source and CS controls; NDN Data format
Outstanding qualification
Execute the three non-overlapping contact stages in round120.html. Capture identical signed Data at B, C and D; inspect CS hits/admission and verify D signature with preprovisioned trust. Demonstrate no simultaneous A-D path, and negative cases for eviction, stale MustBeFresh lookup and missing pull. No runtime experiment performed.