Seal a message behind honest, non-parallelizable compute. Whoever opens it must burn real CPU time to read it — no password, no server, no shortcut. Emerges when the work is done.
RSW sequential-squaring time-lock (poseidon-free): key = SHA-256(g2^T mod N), AES-GCM. Fresh N per message, no trusted setup, wallet-less. The math is open — a native solver just does the same T squarings faster.