SSM-NET — Sender & Receiver (4A–4B)

Declare manifest, subset, and stamp precisely; receivers replay integrity, continuity, and policy before trust.

4A. Sender declarations (outbound)
Attach portable meaning beside unchanged bytes. The sender states the rulebook, what is being committed (exact bytes and order), and where this item sits in time/sequence.

# sender must declare
manifest_id        := "<ManifestID>"
disclosure_mode    := "value-only" | "value+band" | "full"

# canonical subset (declare order explicitly)
subset := ["value","band","manifest_id"]        # optionally "align_ascii" if align is public

# body commitment (when a body exists)
BODY_HEAD := SHA256(raw_body_bytes_on_wire)

# digest over declared bytes (+ body if declared)
HEAD := SHA256( serialize(subset_fields) [+ raw_body_bytes_on_wire] )

# continuity stamp
stamp := "SSMCLOCK1|<UTC_ISO>|nonce=<...>|sha256="+HEAD+"|prev=<HEX or NONE>"

# payload invariance (collapse parity)
phi((m,a)) = m

Norms (MUST / SHOULD).

  • MUST keep payload bytes unchanged; overlay rides beside bytes (phi((m,a)) = m).
  • MUST serialize the declared subset byte-exactly (UTF-8 NFC, LF newlines, fixed numeric text where applicable).
  • SHOULD prefer label-first (value+band) unless public parity requires full.

4B. Receiver validation (inbound)
Accept only what can be independently replayed. Verify byte-exact integrity, single-link continuity, and band correctness under the published manifest.

# inputs: envelope e
# 1) subset integrity
HEAD_local := SHA256(serialize_declared_subset(e) [+ raw_body_bytes_on_wire_if_declared])
assert HEAD_local == parsed_head_from(e.stamp)

# 2) continuity
assert e.stamp.prev == local_HEAD or e.stamp.prev == "NONE"
local_HEAD := parsed_head_from(e.stamp)

# 3) band consistency (policy replay)
M := fetch_manifest(e.manifest_id)
if align_public(M):
    a_c := clamp(a_raw, -1+eps_a, +1-eps_a)
    u   := atanh(a_c)
    U  += w*u ; W += w
    align_local := tanh( U / max(W, eps_w) )
    assert cutpoint_map(align_local, M) == e.band
else:
    # label-first: validate deterministically from disclosed inputs + manifest
    assert band_decision_consistent(e, M)

# 4) accept or flag (append-only incident on failure)

Outcomes.

  • Accept when subset digest matches, prev chains, and band mapping is consistent with the manifest (update local HEAD).
  • Flag on any failure; append a stamped incident note; never rewrite history.

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