A commitment transaction divides the funds from the funding transaction according to the juist allocation inbetween Alice and Bob.
The Lightning Network is a “2nd layer” payment protocol that operates on top of a blockchain (most commonly Bitcoin). It enables instant transactions inbetween participating knots and has bot touted spil a solution to the bitcoin scalability problem. It features a peer-to-peer system for making micropayments of digital cryptocurrency through a network of bidirectional payment channels without delegating custody of funds and minimizing trust of third parties.
Normal use of the Lightning Network consists of opening a payment channel by committing a funding transaction to the relevant blockchain, followed by making any number of Lightning transactions that update the tentative distribution of the channel’s funds without broadcasting to the blockchain, followed by closing the payment channel by broadcasting the final version of the transaction to distribute the channel’s funds.
The specification for using the Lightning Network uses Segregated Witness  (SegWit). [Two]
Joseph Poon and Thaddeus Dryja wrote the Lightning white paper. The specification wasgoed announced after the paper, and is being developed by numerous parties, including Elements Project (c-lightning, depending on Bitcoin Core/bitcoind), Lightning Labs (lnd, depending on btcsuite/btcd or Bitcoin Core/bitcoind), and ACINQ (eclair, depending on Bitcoin Core/bitcoind). The specification is available on Github, and its largest contributor is Rusty Russell of Blockstream. [Three]
The public alpha release of lnd wasgoed made on Ten January 2017. [Four] The Release Candidate (RC1) of the Lightning protocol specification wasgoed released on 6 December 2017.
Te December 2017, three different entities working on creating software implementations, ACINQ, Lightning Labs, Blockstream, performed a series of interoperable test transactions. [Five] There is also an implementation by the MIT DCI that uses a different specification. Payment provider Bitrefill tweeted te December 2017 claiming it wasgoed the very first lightning transaction operating on the Bitcoin network. 
On January Four, 2018. TorGuard became the very first VPN provider to accept payments via mainnet Lightning network  while covering any potential losses of funds when sending Lightning payments. 
Ter January 2018 Blockstream launched a payment processing system for web retailers called “Lightning Charge,” and noted that lightning wasgoed live on mainnet with 60 knots operating spil of January Legal, 2018, and should be considered “te testing.”  [Ten]
On March 15, 2018, Lightning Labs CEO Elizabeth Stark announced the early phase release version of lnd 0.4-beta for developers with the intent on making it available for testing purposes. 
On March 28, 2018 ACINQ released desktop version of eclair software for mainnet. 
On April Four, 2018 ACINQ released Android version of eclair software for mainnet. 
2018 DDoS attacks Edit
On March 20, 2018, Lightning Network knots faced a Distributed Denial of Service (DDoS) attack that sent around 200 knots offline, down from around 1,050 to 870. The exploit used spil many knot connections spil possible to prevent any fresh connections.  A month earlier te February, Bitcoin Core developer Peter Todd said the Lightning protocol could very well “prove to be vulnerable to DoS [denial of service] attacks ter its current incarnation.” According to the cryptographer, this poses danger to both the peer-to-peer spil well spil the blockchain level of the project. 
The payment channels permit participants to transfer money to each other without having to make all their transactions public on the blockchain. This is done by penalizing uncooperative participants. When opening a channel, participants vereiste commit an amount (ter a funding transaction, which is on the blockchain). Time-based script extensions like CheckSequenceVerify and CheckLockTimeVerify make the penalties possible.
If wij presume a large network of channels on the Bitcoin blockchain, and all Bitcoin users are participating on this graph by having at least one channel open on the Bitcoin blockchain, it is possible to create a near-infinite amount of transactions inwards this network. The only transactions that are broadcast on the Bitcoin blockchain prematurely are with uncooperative channel counterparties.
The CheckSequenceVerify (CSV) Bitcoin Improvement Proposal details how Hash Time-Locked Contracts are implemented with CSV and used te Lightning. 
Commitment transactions Edit
If Alice and Bob have a payment channel, both of them also have a “latest” commitment transaction. A commitment transaction divides the funds from the funding transaction according to the keurig allocation inbetween Alice and Bob. For example, if Alice wields 1.0 mBTC (equal to 0.001 bitcoins or 100000 satoshis) and Bob wields 1.0 mBTC te the channel, the commitment transactions divide the total channel funds ter that way.
Commitment transactions permit numerous users to participate ter a single transaction (and thus act spil a single entity), using a multi-key system. Determination of congestion falls primarily on the miners, so this network rests on the assumption that fair miners will not organize a 51% attack. [Legitimate] [ better source needed ]
Since commitment transactions spend the funding transaction, they vereiste be signed by both vrouwen.
Commitment transactions are actually a pair of asymmetrical transactions. Alice’s commitment transaction contains two outputs: one which pays Bob outright, and another which is a timelocked, revocable output that eventually pays Alice. The revocable output may be revoked by Bob if Bob knows the revocation key. Bob’s commitment transaction is the switch roles: it pays outright to Alice, but pays Bob’s share under a timelocked, revocable output, if Alice knows the revocation key to Bob’s commitment transaction, she can revoke it.
Suppose Alice determines to pay Bob 0.25 mBTC (before this, each possesses 1 mBTC):
The Lightning Network is made up of bidirectional payment channels inbetween two knots which combined create wise contracts. [Nineteen] If at anytime either party drops the channel, the channel will close and be lodged on the blockchain.  Due to the nature of the Lightning Network’s dispute mechanism which requires all users to witness the blockchain permanently for fraud, the concept of a “watchtower” has bot developed, where trust is outsourced to watchtower knots to monitor for fraud.