As a professional translator, I have translated the news article into English:
The Babylon checkpoint pause rule: PoS and Babylon validators must pause the blockchain when observing an unavailable Babylon checkpoint. Here, the unavailable Babylon checkpoint is a hash with an aggregate BLS signature of 2/3 Babylon validators, which is speculated to correspond to a Babylon block that cannot be observed. If Babylon validators do not pause the Babylon blockchain, an attacker can reveal a previously unavailable Babylon chain, thus changing the canonical Babylon chain in the view of later clients. Similarly, if PoS validators do not pause the PoS chain, an attacker can reveal previously unavailable PoS attack chains and previously unavailable Babylon chains to canonicalize the PoS chain in the view of later clients. This is because the later revealed dark Babylon chain has an earlier timestamp on Bitcoin, and includes checkpoints of the later revealed PoS attack chain. Just like the pause rule for unavailable PoS checkpoints, the above rule illustrates why we require Babylon block hashes sent as checkpoints to be accompanied by an aggregate BLS signature to prove the signatures of 2/3 Babylon validators. If the Babylon checkpoint is not signed, any adversary can send any hash and claim it is the hash of an unavailable Babylon block checkpoint on Bitcoin. Then, PoS validators and Babylon validators would have to wait for a checkpoint with no unavailable Babylon or PoS chains in its pre-image! Creating an unavailable Babylon chain requires disrupting at least 2/3 of Babylon validators. However, in the assumed attack above, the attacker paused all chains in the system without even disrupting a single Babylon or PoS validator. To prevent such attacks, we require Babylon checkpoints to be proven through aggregate signatures; thus, there will only be an unavailable Babylon checkpoint when indeed 2/3 of validators are compromised. Due to the cost of disrupting Babylon validators, such data availability attacks are highly unlikely to occur. However, in extreme cases, it would impact all PoS chains by forcing them to pause.