怎麼會有人廣播中間閃電交易？網路費用從何而來？

假設 Alice 和 Bob 創建了一個通道，Alice 在其中鎖定了她的 100 mBTC。

Alice 100mBTC 和 Bob 0 mBTC ——–> 2-of-2 合約

Alice 通過這個渠道向 Bob 支付 30mBTC：

---

Alice Commitment Txn:

Input: 
- Contract 
- Alice Signature
- Bob Signature

Output: 
- 70 mBTC (Alice's Balance)
- - If revocation key then pay to Bob's Pubkey.
- - Else Alice can pay herself after one day.
- 30 mBTC (Bob's balance)
- - Pay to Bob's pubkey

---

和，

---

Bob's Commitment Transaction:

Input: 
- Contract 
- Alice Signature
- Bob Signature

Output: 
- 30 mBTC (Bob's Balance)
- - If revocation key then pay to Alice's Pubkey.
- - Else Bob can pay herself after one day.
- 70 mBTC (Alice's balance)
- - Pay to Alice's pubkey

---

然後 Alice 和 Bob 在發送下一個交易之前共享撤銷密鑰。

現在 Alice 通過這個渠道向 Bob 支付 10mBTC：

---

Alice Commitment Txn:

Input: 
- Contract 
- Alice Signature
- Bob Signature

Output: 
- 60 mBTC (Alice's Balance)
- - If revocation key then pay to Bob's Pubkey.
- - Else Alice can pay herself after one day.
- 40 mBTC (Bob's balance)
- - Pay to Bob's pubkey

---

和，

---

Bob's Commitment Transaction:

Input: 
- Contract 
- Alice Signature
- Bob Signature

Output: 
- 40 mBTC (Bob's Balance)
- - If revocation key then pay to Alice's Pubkey.
- - Else Bob can pay herself after one day.
- 60 mBTC (Alice's balance)
- - Pay to Alice's pubkey

---

Alice 試圖通過發布之前的交易來欺騙 Bob：

---

Alice Commitment Txn:

Input: 
- Contract 
- Alice Signature
- Bob Signature

Output: 
- 70 mBTC (Alice's Balance)
- - If revocation key then pay to Bob's Pubkey.
- - Else Alice can pay herself after one day.
- 30 mBTC (Bob's balance)
- - Pay to Bob's pubkey

---

我無法理解 Alice 如何發布交易，因為在比特幣區塊鏈上確認交易沒有網路交易費用。

請幫助我了解我在這裡缺少什麼。

交易確實有費用，並且是在渠道打開之前協商好的。參與者將在創建交易之前確定要在承諾交易上設置的費用。因此，每筆承諾交易都包含交易費用，並且可以發送到網路。

這在單方面關閉的情況下是必需的。單邊關閉有一個參與者廣播最新的承諾交易。由於該承諾交易必須能夠確認，它必須支付交易費用。費用只能在創建承諾時設置，這就是所做的。

引用自：https://bitcoin.stackexchange.com/questions/110012