Adversary controls the network and may have arbitrary compute power.

1. 51% hash attack → reorg/censorship.
2. Eclipse → isolate node, censor mempool.
3. Long-range → no historical binding once power drops.
4. Cartelization → economic capture.

1. Signature validity: verify(pubkey, canon(tx with sig=""), sig) must hold.
2. Ownership: input.pubkey must equal UTXO.pubkey.
3. Conservation: Σinputs ≥ Σoutputs (fee = difference).
4. Fork choice: maximize cumulative difficulty.
5. Declared limitation: no asymptotic security accumulation.

URC does NOT claim compounding security, permanent decentralization, or state-resistance.