I was studying Lightning Network recently and got into confusion.
I want to know that the process order of generating a new state to revoke the old state in the Lightning Network. When a new commitment transaction is generated, do the two parties firstly exchange signatures for the new transaction, and then the private key used in the previous commitment transaction is sent to the other party to revoke the previous state, or is the situation reversed? (That is, the private key is exchanged first, and then the new commitment transaction pair is signed and exchanged).
Or there is another more specific order?