How does Raiden Network prevent the attack that uses stale state ?
I understood that Raiden Network uses "nonce"(like round number for ordering) for off-chain payment in single payment channel between two nodes. But Ethereum does not support timelock.
In Lightning Network, it prevents malicious node from placing stale state onto the blockchain by using timelock. So, what I wonder is how does Raiden Network prevents such attacks use stale state ?
I read some part of Raiden Network Document. it says that Raiden Network uses "Monitoring Service". Is it right ? or any other mechanism exists ? How to prevent malicious node from placing old state onto the blockchain in Ethereum ?
I think nodes should update their balance state with round number onto the blockchain per one off-chain payment if there is no timelock. Without this, how prove that one state is the up-to-date ?