So we're just reiterating the lesson "Satoshi was not an infinite being of infinite wisdom" here. Satoshi just gets a pass because of how awesome Bitcoin is. Now as we saw in the Spilman Channels discussion, transaction malleability means that any pre-signed offchain transaction can easily be invalidated by flipping the sign of the signature of the funding transaction while the funding transaction is not yet confirmed.
Instead of paying to a 2-of-2 in order to set up the funding transaction, you pay to a SCRIPT which is basically "2-of-2, OR this singlesig after a specified lock time". With this, there is no backoff transaction that is pre-signed and which refers to a specific txid.
Instead, you can create the backoff transaction later, using whatever txid the funding transaction ends up being confirmed under. Since the funding transaction is immutable once confirmed, it is no longer possible to change the txid afterwards. One of the more direct predecessors of the Lightning Network was the hub-spoke model discussed by Peter Todd. In this model, instead of payers directly having channels to payees, payers and payees connect to a central hub server. This allows any payer to pay any payee, using the same channel for every payee on the hub.
Similarly, this allows any payee to receive from any payer, using the same channel. Remember from the above Spilman example? When you open a channel to the bartender, you have to wait around for the funding tx to confirm. This will take an hour at best. Now consider that you have to make channels for everyone you want to pay to. That's not very scalable.
So the Todd hub-spoke model has a central "clearing house" that transport money from payers to payees. The "Moonbeam" project takes this model. Of course, this reveals to the hub who the payer and payee are, and thus the hub can potentially censor transactions. In any case, the ability of the central hub to monitor payments means that it can surveill the payer and payee, and then sell this private transactional data to third parties.
This loss of privacy would be intolerable today. Peter Todd also proposed that there might be multiple hubs that could transport funds to each other on behalf of their users, providing somewhat better privacy. Another point of note is that at the time such networks were proposed, only unidirectional Spilman channels were available.
Thus, while one could be a payer, or payee, you would have to use separate channels for your income versus for your spending. Worse, if you wanted to transfer money from your income channel to your spending channel, you had to close both and reshuffle the money between them, both onchain activities.
Poon-Dryja Lightning Network Bidirectional two-participant channels. The Poon-Dryja channel mechanism has two important properties: Bidirectional. No time limit. Both the original Satoshi and the two Spilman variants are unidirectional: there is a payer and a payee, and if the payee wants to do a refund, or wants to pay for a different service or product the payer is providing, then they can't use the same unidirectional channel.
The Poon-Dryjam mechanism allows channels, however, to be bidirectional instead: you are not a payer or a payee on the channel, you can receive or send at any time as long as both you and the channel counterparty are online. Further, unlike either of the Spilman variants, there is no time limit for the lifetime of a channel. Instead, you can keep the channel open for as long as you want.
Both properties, together, form a very powerful scaling property that I believe most people have not appreciated. With unidirectional channels, as mentioned before, if you both earn and spend over the same network of payment channels, you would have separate channels for earning and spending. You would then need to perform onchain operations to "reverse" the directions of your channels periodically.
Secondly, since Spilman channels have a fixed lifetime, even if you never used either channel, you would have to periodically "refresh" it by closing it and reopening. With bidirectional, indefinite-lifetime channels, you may instead open some channels when you first begin managing your own money, then close them only after your lawyers have executed your last will and testament on how the money in your channels get divided up to your heirs: that's just two onchain transactions in your entire lifetime.
That is the potentially very powerful scaling property that bidirectional, indefinite-lifetime channels allow. I won't discuss the transaction structure needed for Poon-Dryja bidirectional channels it's complicated and you can easily get explanations with cute graphics elsewhere. There is a weakness of Poon-Dryja that people tend to gloss over because it was fixed very well by RustyReddit : You have to store all the revocation keys of a channel.
This implies you are storing 1 revocation key for every channel update, so if you perform millions of updates over your entire lifetime, you'd be storing several megabytes of keys, for only a single channel. RustyReddit fixed this by requiring that the revocation keys be generated from a "Seed" revocation key, and every key is just the application of SHA on that key, repeatedly.
You can store that in O 1 space. Then for the next revocation, I tell you SHA seed. So you can remember just the most recent revocation key, and from there you'd be able to compute every previous revocation key. When you start a channel, you perform SHA on your seed for several million times, then use the result as the first revocation key, removing one layer of SHA for every revocation key you need to generate.
RustyReddit not only came up with this, but also suggested an efficient O log n storage structure, the shachain, so that you can quickly look up any revocation key in the past in case of a breach. People no longer really talk about this O n revocation storage problem anymore because it was solved very very well by this mechanism.
Another thing I want to emphasize is that while the Lightning Network paper and many of the earlier presentations developed from the old Peter Todd hub-and-spoke model, the modern Lightning Network takes the logical conclusion of removing a strict separation between "hubs" and "spokes".
Any node on the Lightning Network can very well work as a hub for any other node. Thus, while you might operate as "mostly a payer", "mostly a forwarding node", "mostly a payee", you still end up being at least partially a forwarding node "hub" on the network, at least part of the time. This greatly reduces the problems of privacy inherent in having only a few hub nodes: forwarding nodes cannot get significantly useful data from the payments passing through them, because the distance between the payer and the payee can be so large that it would be likely that the ultimate payer and the ultimate payee could be anyone on the Lightning Network.
We can decentralize if we try hard enough! Smart people can solve problems. It's kinda why they're smart. This post is long enough as-is, LOL. But for now, it uses a novel "decrementing nSequence channel", using the new relative-timelock semantics of nSequence not the broken one originally by Satoshi.
It actually uses multiple such "decrementing nSequence" constructs, terminating in a pair of Spilman channels, one in both directions thus "duplex". Maybe I'll discuss it some other time. The realization that channel constructions could actually hold more channel constructions inside them the way the Decker-Wattenhofer puts a pair of Spilman channels inside a series of "decrementing nSequence channels" lead to the further thought behind Burchert-Decker-Wattenhofer channel factories.
Basically, you could host multiple two-participant channel constructs inside a larger multiparticipant "channel" construct i. Further, we have the Decker-Russell-Osuntokun or "eltoo" construction. I'd argue that this is "nSequence done right". I'll write more about this later, because this post is long enough. Bitcoin offchain scaling is more powerful than you ever thought.
This is a followup of my older post about the history of payment channel mechanisms. The "modern" payment channel system is Lightning Network, which uses bidirectional indefinite-lifetime channels, using HTLCs to trustlessly route through the network.
However, at least one other payment channel mechanism was developed at roughly the same time as Lightning, and there are also further proposals that are intended to replace the core payment channel mechanism in use by Lightning. Now, in principle, the "magic" of Lightning lies in combining two ingredients: Offchain updateable systems.
HTLCs to implement atomic cross-system swaps. We can replace the exact mechanism implementing an offchain updateable system. Secondly we can replace the use of HTLCs with another atomic cross-system swap, which is what we would do when we eventually switch to payment points and scalars from payment hashes and preimages. So let's clarify what I'll be discussing here: I will be discussing mechanisms for the offchain updateable system, which are generally called "payment channel mechanisms".
The exact contracts that can be transported across such systems, such as HTLCs, the Scriptless-Script point-based variant, and Discrete Log Contracts, will have to wait another post. Payment channel mechanisms are designed to be trust-minimized. They might not achieve this design goal consider the broken Satoshi sequence numbers, or the pre-SegWit Spilman, which I still class as "payment channel mechanism" , but mechanisms which invoke trust in one participant or other as inherent parts of their design are not true payment channels.
Such constructions might be of interest, but I will not discuss them here. Now I might use "we" here to refer to what "we" did to the design of Bitcoin, but it is only because "we" are all Satoshi, except for Craig Steven Wright. So, let's present the other payment channel mechanisms. But first, a digression.
Last time we used nSequence, we had the unfortunate problem that it would be easy to rip off people by offering a higher miner fee for older state where we own more funds, then convince the other side of the channel to give us goods in exchange for a new state with tiny miner fees, then publish both the old state and the new state, then taunt the miners with "so which state is gonna earn you more fees huh huh huh?
This problem, originally failed by Satoshi, was such a massive facepalm that, in honor of miners doing the economically-rational thing in the face of developer and user demands when given a non-final nSequence, we decided to use nSequence as a flag for the opt-in replace-by-fee.
Because you'd totally abuse nSequence to bribe miners in order to steal money from your bartender, especially if your bartender is not a werebear. Of course, using a 4-byte field for a one-bit flag to opt-in to RBF or not was a massive waste of space, so when people started proposing relative locktimes, the nSequence field was repurposed. Basically, in Bitcoin as of the time of this writing early if nSequence is less than 0x it can be interpreted as a relative timelock.
I'll spare you the details here, BIP68 has them, but basically nSequence can indicate much like nLockTime either a "real world" relative lock time i. Of course, this is the Bitcoin universe and "seconds" is a merely human delusion, so we will use blocks exclusively.
This ensures that the nSequence field is a relative-locktime i. It is important to mention the new, modern meaning of nSequence, because it is central to many of the modern payment channel mechanisms, including Lightning Poon-Dryja.
Poetic justice is a thing. Go go new nSequence! Decker-Wattenhofer "Duplex Micropayment Channels" Mechanisms-within-mechanisms for a punishment-free bidirectional indefinite-lifetime payment channel. The Decker-Wattenhofer paper was published in , but the Poon-Dryja "Lightning Network" paper was published in However, the Decker-Wattenhofer paper mentions the Lightning mechanism, specifically mentioning the need to store every old revocation key i.
Maybe Poon-Dryja presented the Lightning Network before making a final published paper in , or something. Either that or cdecker is the Bitcoin time traveler. It's a little hard to get an online copy now, but as of late this seems to work: copy Now the interesting bit is that Decker-Wattenhofer achieves its goals by combining multiple mechanisms that are, by themselves, workable payment channel mechanisms already, except each has some massive drawbacks.
By combining them, we can minimize the drawbacks. So let's go through the individual pieces. Indefinite-lifetime Spilman channels As mentioned before, Spilman channels have the drawback that they have a limited lifetime: the lock time indicated in the backoff transaction or backoff branch of the script. However, instead of an absolute lock time, we can use a relative locktime.
In order to do so, we use a "kickoff" transaction, between the backoff transaction and the funding transaction. Our opening ritual goes this way, between you and our gender-neutral bartender-bancho werebear: First, you compute the txid for the funding transaction and the kickoff transaction.
The funding transaction takes some of your funds and puts it into a 2-of-2 between you and the bartender, and the kickoff is a 1-input 1-output transaction that spends the funding transaction and outputs to another 2-of-2 between you and the bartender. Then, you generate the backoff transaction, which spends the kickoff transaction and returns all the funds to you. The bartender signs the backoff, and gives back the fully-signed transaction to you. You sign the kickoff transaction, then send it to the bartender.
The bartender signs the kickoff, and gives it back to you fully signed. You sign and broadcast the funding transaction, and both of you wait for the funding transaction to be deeply confirmed. The above setup assumes you're using SegWit, because transaction malleability fix. At any time, either you or the bartender can broadcast the kickoff transaction, and once that is done, this indicates closure of the channel.
You do this if you have drunk enough alcoholic beverages, or the bartender could do this when he or she is closing the bar. Now, to get your drinks, you do: Sign a transaction spending the kickoff, and adding more funds to the bartender, to buy a drink. This transaction is not encumbered with an nSequence.
Hand the signed transaction to the bartender, who provides you with your next drink. The channel is closed by publishing the kickoff transaction. Both of you have a fully-signed copy of the kickoff, so either of you can initiate the close. On closure publication and confirmation of the kickoff transaction , there are two cases: You fail to pick up any chicks at the bar I prefer female humans of optimum reproductive age myself rather than nestling birds, but hey, you do you so you didn't actually spend for drinks at all.
In this case, the bartender is not holding any transactions that can spend the kickoff transaction. You wait for the agreed-upon delay after the kickoff is confirmed, and then publish the backoff transaction and get back all the funds that you didn't spend. You spend all your money on chicks and end up having to be kicked into a cab to get back to your domicile, because even juvenile birds can out-drink you, you pushover. The bartender then uses the latest transaction you gave the one that gives the most money to him or her it would be foolish of him or her to use an earlier version with less money!
Pro: Number of updates is limited only by the amount of money you have in the "payer" side of the channel. Pro: no lifetime limit. You can keep the channel open indefinitely if you don't transact over it. Pro: The delay can be very small. Con: Unidirectional. Decrementing nSequence channels Enforcing order by reducing relative locktimes.
I believe this to be novel to the Decker-Wattenhofer mechanism, though I might be missing some predecessor. This again uses the new relative-locktime meaning of nSequence. As such, it also uses a kickoff transaction like the above indefinite-lifetime Spilman channel.
Set up is very similar to the setup of the above indefinite-lifetime Spilman channel, except that because this is bidirectional, we can actually have both sides put money into the initial starting backoff transaction. We also rename the "backoff" transaction to "state" transaction. Basically, the state transaction indicates how the money in the channel is divided up between the two participants.
The "backoff" we sign during the funding ritual is now the first state transaction. Both sides keep track of the current state transaction which is initialized to the first state transaction on channel establishment. Finally, the starting nSequence of the first state transaction is very large usually in the dozens or low hundreds of blocks. Suppose one participant wants to pay the other. The ritual done is then: A new version of the current state transaction is created with more money in the payee side.
This new version has nSequence that is one block lower than the current state transaction in practice it should be a few blocks lower, not just one, because sometimes miners find blocks in quick succession. Both sides exchange signatures for the new state transaction. Both sides set the new state transaction as the current state transaction that will be the basis for the next payment. When the channel is closed by publication of the kickoff transaction, then the transaction with the lowest nSequence becomes valid earlier than the other state transactions.
This is enough to enforce that the most recent state transaction the one with the lowest nSequence, and thus the first to become valid is published. Pro: bidirectional. Pro: indefinite lifetime, at least if no updates are done. Pro: it shows that life is not without a sense of irony. The original design for nSequence replacement required an incrementing nSequence using the original Satoshi's Vision interpretation of nSequence which doesn't work.
But this channel mechanism instead uses a decrementing nSequence using the new Bitcoin Core interpretation of nSequence as a relative timelock which does, in fact, work. Con: Number of updates is limited by the starting maximum nSequence delay. Increasing this delay increases the encumbrance if the channel is closed without any activity, but reducing this delay reduces the number of payments in either direction you can use before you have to close the channel and recreate it. For example, let's have a maximum of blocks of delay.
Each update, we decrement the nSequence by 4, because that handles up to the very rare case where up to 3 blocks arrive in very close succession to each other. That only gives us 36 updates for a worst-case of one day of delay, a very bad tradeoff. Con: You can only be safely offline for a number of blocks equal to the "step", but the maximum delay you may incur is the product of the step times the number of updates you want to make.
So you want a small step because you don't want your worst-case lock time to be large but you want a big step because you want to still be safe even if you go offline for a long time. Mechanism-within-mechanism Combining the ingredients of the Decker-Wattenhofer Duplex Micropayment Channels concoction. Of note is that we can "chain" these mechanisms together in such a way that we strengthen their strengths while covering their weaknesses.
A note is that both the indefinite-lifetime nSequence Spilman variant, and the above decrementing nSequence mechanism, both have "kickoff" transactions. However, when we chain the two mechanisms together, it turns out that the final transaction of one mechanism also serves as the kickoff of the next mechanism in the chain.
So for example, let's chain two of those decrementing nSequence channels together. Let's make them blocks maximum delay each, and decrement in units of 4 blocks, so each of the chained mechanisms can do 37 updates each.
We start up a new channel with the following transactions: A funding transaction paying to a 2-of-2, confirmed deeply onchain. All other transactions are offchain until closure. A kickoff transaction spending the funding transaction output, paying to a 2-of A "stage 1" decrementing nSequence state transaction, spending the kickoff, with current nSequence , paying to a 2-of A "stage 2" decrementing nSequence state transaction, spending the stage 1, with current nSequence , paying to the initial state of the channel.
When we update this channel, we first update the "stage 2" state transaction, replacing it with an nSequence lower by 4 blocks. So after one update our transactions are: A funding transaction paying to a 2-of-2, confirmed deeply onchain. A "stage 2" decrementing nSequence state transaction, spending the stage 1, with current nSequence , paying to the second state of the channel. Things become interesting when we reach the "stage 2" having nSequence 0.
On the next update, we create a new "stage 1", with an nSequence that is 4 lower, and "reset" the "stage 2" back to an nSequence of This is safe because even though we have a "stage 2" with shorter nSequence, that stage 2 spends a stage 1 with an nSequence of , and the stage 1 with nSequence of would beat it to the blockchain first. The number of stages can be extended indefinitely, and your only drawback would be the amount of blockchain space you'd spend for a unilateral close.
Mutual cooperative closes can always shortcut the entire stack of staged transactions and cut it to a single mutual cooperative close transaction. But that's not all! You might be wondering about the term "duplex" in the name "Duplex Micropayment Channels".
That's because the last decrementing nSequence stage does not hold the money of the participants directly. Instead, the last stage holds two indefinite-lifetime Spilman channels. As you might remember, Spilman channels are unidirectional, so the two Spilman channels represent both directions of the channel. Thus, duplex. Let's go back to you and your favorite werebear bartender. If you were using a Decker-Wattenhofer Duplex Micropayment Channel, you'd have several stages of decrementing nSequence, terminated in two Spilman channels, a you-to-bartender channel and a bartender-to-you channel.
Suppose that, while drinking, the bartender offers you a rebate on each drink if you do some particular service for him or her. Let us not discuss what service this is and leave it to your imagination. So you pay for a drink, decide you want to get the rebate, and perform a service that the bartender finds enjoyable.
So you transfer some funds on the you-to-bartender direction, and then later the bartender transfers some funds in the bartender-to-you channel after greatly enjoying your service. Suppose you now exhaust the you-to-bartender direction. However, you note that the rebates you've earned are enough to buy a few more drinks.
What you do instead is to update the staged decrementing nSequence mechanisms, and recreate the two Spilman directions such that the you-to-bartender direction contains all your current funds and the bartender-to-you direction contains all the bartender's funds. With this, you are now able to spend even the money you earned from rebates. At the same time, even if the staged decrementing nSequence mechanisms only have a few hundred thousand updates, you can still extend the practical number of updates as long as you don't have to reset the Spilman channels too often.
Pro: chaining allows more possible updates! Pro: no "toxic waste"! That is, old backups of your channel state database won't cause you to lose funds automatically. Con: unilateral closes have long lock times, due to the chaining of decrementing-nSequence mechanisms.
Con: unilateral closes put a lot of transactions onchain, due to the chaining of multiple nested mechanisms. This is because HTLCs have an absolute timelock in their contract, and this can only be enforced onchain.
However, the existence of nSequence delays means that absolute timelocks need to trigger unilateral closes several blocks before the absolute timelock, by the nSequence total delta of all the stacked mechanisms.
In Poon-Dryja you can safely keep a channel open until just before the absolute timelock expires. The HTLCs used in Lightning are "cancellable" because of a nifty ability of every offchain update mechanism: every contract has an additional clause " This is not a degradation of security since the HTLCs in a channel are between the two users of the channel, so both of them need to agree anyway in order to accept such a cancellation.
This ability is used to propagate forwarding failures back to the payer: instead of waiting for the HTLCs to time out, the node just says to the sender "between you and me, this HTLC won't propagate anyway, because 'insert some reason here', so let's just put the money in it back to you". However, this seems unsafe with Spilman channels, as a cancelled HTLC will still be available on older states of the Spilman channel, and potentially claimable by the payee end up until the timelock.
Removing the Spilman channels at the end would remove this issue, but now you are limited to a few hundred thousand updates even with lots of decrementing-nSequence layers. Burchert-Decker-Wattenhofer Channel Factories Because you like channels so much, you put channels inside channels so you could pay while you pay. For example, it suggests nesting a decrementing-nSequence mechanism inside another decrementing-nSequence mechanism, and having as well an unlimited-lifetime Spilman channel at the end.
In the Decker-Wattenhofer case, it is used to support the weakness of one mechanism with the strength of another mechanism. One thing to note is that while the unlimited-lifetime Spilman channel variant used is inherently two-participant there is one payer and one payee , the decrementing-nSequence channel mechanism can be multiparticipant. Another thing of note is that nothing prevents one mechanism from hosting just one inner mechanism, just as it is perfectly fine for a Lightning Network channel to have multiple HTLCs in-flight, plus the money in your side, plus the money in the counterparty's side.
As these are "just" Bitcoin-enforceable contracts, there is no fundamental difference between an HTLC, and a payment channel mechanism. Thus the most basic idea of the Burchert-Decker-Wattenhofer Channel Factories paper is simply that we can have a multiparticipant update mechanism host multiple two-party update mechanisms.
The outer multiparticipant update mechanism is called a "channel factory" while the inner two-party update mechanisms are called "channels". The exact mechanism used in the Burchert-Decker-Wattenhofer paper uses several decrementing-nSequence mechanisms to implement the factory, and Decker-Wattenhofer Duplex Micropayment Channels to implement the channel layer.
So it is in fact possible to have chained Decker-Wattenhofer decrementing-nSequence mechanisms to implement the factory level, while the channels are simply Poon-Dryja channels. Conclusion So this concludes for now an alternative mechanism to the classic Poon-Dryja that Lightning uses. The tradeoffs are significantly different between Decker-Wattenhofer vs Poon-Dryja: Decker-Wattenhofer: No toxic waste: old data stolen from you, or which you inadvertently use, is not going to lose all your funds.
Decker-Wattenhofer: Multiple participants in a single offchain mechanism, enabling things like Channel Factories. Poon-Dryja: Doesn't have ridiculously long lock times in the unilateral close case. Poon-Dryja: Supports HTLCs for trustless forwarding not clear if Decker-Wattenhofer fully supports this without sacrificing the duplexed indefinite-lifetime Spilman channels at the end.
Copyright Copyright Alan Manuel K. Released under CC-BY. That's better for the secret miners then. You can then process this input in any way you like. Something like that. You are having me here, let's work together! I find it hard to believe too. It's described pretty good  so I better say nothing now  we focus on our Ethash chip  then based on that, we are happy to walk interested people through the design and what else it can do  that's a better approach from my view than making claims that are laughed away rightfully so, because no silicon I'm pretty sure you don't.
I am fairly new to this space myself Have not had issues. I am just sharing the "best" document I know today. For chipmakers, in-protocol rewards create an economic incentive to accelerate those things. I suppose they need all the help they can get  Bitcoin Cash I dont think anyone believes you can't make a more efficient cn-gpu asic than a gpu - but that it would not be orders of magnitude faster Though, in reality, there will always be divergence between social worlds. Not every body has the same vision of the future.
Reaching societal consensus on reality tomorrow is not always easy  absolutely. Money distorts. I just re-read Satoshi Nakamoto's initial introduction to Bitcoin, and he clearly mentions the inability of current banks, due to their "massive overhead", to handle micropayments in an economically viable way the cost of processing such a payment is non negligible compared to the value of the payment.
I think Nakamoto implied that Bitcoin would solve that, but as the mining gets more expensive, a lot of people expect the transaction fees to go up steadily. Even today, the cost of a small transaction is higher than the cost of a big one. It kinda works but isn't ideal. Am I missing something obvious? Hello again. It's been a while. People have been emailing me about once a week or so for the last year to ask if I'm coming back to Bitcoin now that Bitcoin Cash exists.
And a couple of weeks ago I was summoned on a thread called "Ask Mike Hearn Anything" , but that was nothing to do with me and I was on holiday in Japan at the time. So I figured I should just answer all the different questions and answers in one place rather than keep doing it individually over email.
Firstly, thanks for the kind words on this sub. I don't take part anymore but I still visit occasionally to see what people are talking about, and the people posting nice messages is a pleasant change from three years ago. Secondly, who am I? Some new Bitcoiners might not know.
I am Satoshi. Just kidding. I'm not Satoshi. I was a Bitcoin developer for about five years, from I was also one of the first Bitcoin users, sending my first coins in April to SN , about 4 months after the genesis block. I worked on various things: I wrote the first documentation on smart contracts , gave the first talk on the concept and based on some hints from Satoshi designed and documented what I called " micropayment channels ".
I had numerous email exchanges with Satoshi. I didn't know at the time that this was very rare. My main effort was an implementation of a Java library called bitcoinj. This was the engine used in the first p2p mobile wallet "Bitcoin Wallet for Android" , and the first p2p desktop wallet that was faster to run than Bitcoin [Core] itself MultiBit. These together were responsible for around 2. It was used in the first trustless gambling site SatoshiDice , over products and projects, and many academic research papers.
With Matt Corrallo I implemented and demonstrated the first version of micro payment channels. I put together a demo of a file server that charged micropayments using a GUI called Payfile mentioned in New Scientist here. I used to have a video of this but unfortunately it no longer seems to be on YouTube. Payment channels went on to be used in the design of the Lightning Network. I built an open source peer to peer Kickstarter-style crowdfunding app that used smart contracts, called Lighthouse.
It is no longer maintained or available but there's still an intro video here , the source code is here , and I gave a development retrospective talk on what was easy and what was hard about building really decentralised apps on Bitcoin. It was intended to be used to fund Bitcoin upgrades. I spoke at a lot of conferences, like this talk on autonomous agents that use cryptocurrency. My last conference appearance was a 30 minute session where I live coded a block chain timestamping app from scratch.
You can see a trend here - I was always interested in developing peer to peer decentralised applications that used Bitcoin. After Blockstream successfully took over Bitcoin Core and expelled anyone who opposed them, Gavin and I forked Bitcoin Core to create Bitcoin XT , the first alternative node implementation to gain any serious usage.
The creation of XT led to the imposition of censorship across all Bitcoin discussion forums and news outlets, resulted in the creation of this sub, and Core supporters paid a botnet operator to force XT nodes offline with DDoS attacks.
They also convinced the miners and wider community to do nothing for years, resulting in the eventual overload of the main network. I left the project at the start of , documenting my reasons and what I expected to happen in my final essay on Bitcoin in which I said I considered it a failed experiment. The last two years Left Bitcoin After all that went down I started a new project called Corda.
Corda incorporates many ideas I had back when I was working on Bitcoin but couldn't implement due to lack of time, resources, because of ideological wars or because they were too technically radical for the community. So even though it's doesn't provide a new cryptocurrency out of the box, it might be interesting for the Bitcoin Cash community to study anyway.
By resigning myself to Bitcoin's fate and joining R3 I could go back to the drawing board and design with a lot more freedom, creating something inspired by Bitcoin's protocol but incorporating all the experience we gained writing Bitcoin apps over the years.
The most common question I'm asked is whether I'd come back and work on Bitcoin again. The obvious followup question is - come back and work on what? If you want to see some of the ideas I'd have been exploring if things had worked out differently, go read the Corda tech white paper.
Outputs in Corda called "states" can be arbitrary data structures instead of just coin amounts, so you don't need hacks like coloured coins anymore. You can track arbitrary fungible assets, but you can also model things like the state of a loan, deal, purchase order, crate of cargo etc. Transactions are structured as Merkle trees. Smart contracts are stateless predicates like in Bitcoin, but you can loop like in Ethereum. Unlike Bitcoin and Ethereum we do not invent our own VM or languages.
Transactions can have files attached to them. Smart contracts in Corda are stored in attachments and referenced by hash, so large programs aren't duplicated inside every transaction. The P2P network is encrypted. Back in I wrote that Bitcoin needed a store and forward network , to make app dev easier, and to improve privacy.
Corda doesn't have a store and forward network - Corda is a store and forward network. It has a "flow framework" that makes structured back-and-forth conversations very easy to program. This makes protocols like payment channelss a lot quicker and easier to implement, and would have made Lighthouse much more straightforward.
A big part of my goal with Corda was to simplify the act of building complicated decentralised applications, based on those Bitcoin experiences. Lighthouse took about 8 months of full time work to build, but it's pretty spartan anyway. That's because Bitcoin offers almost nothing to developers who want to build P2P apps that go beyond simple payments. Corda does. Best 30 atm locations in el cerrito, ca with reviews - yp.
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Bitcoin is the revolutionary P2P digital cash envisioned by Satoshi Nakamoto. Many attempts have been made to dethrone Bitcoin, but real connoisseurs accept no imitations. Bitcoin is referred to as digital gold with good reason. It is borderless, decentralized, censorship resistant, and open source. The Bitcoin market is not the most volatile crypto market, but is by far the most liquid and most traded.
The network has been running for 10 years, but development is in no way stagnant. Bitcoin developers are some of the best in the space, and they are constantly looking for safe ways to improve and upgrade the system. Recent highlights:. Read the Bitcoin white paper or see this page if you want to learn more about Bitcoin. A lot of hours has gone into making the new version more user friendly and informative.
Hope you like it Both longs and shorts are measured in BTC. On shorter timeframes say below one week longs and shorts are typically almost straight lines because they don't fluctuate much and because of Y-axis scaling. The two charts below the price chart show the same values for total longs and shorts, but capture the short term flucturations much better. Pain and Mana is a health-score that is calculated by Datamish. Both longs and shorts have a pain and a mana score.
Pain is bad and mana is good. Pain score increases when traders are adding to Bitcoin positions while the market is moving against them. So they could be in for a squeeze. Increased mana score happens when traders are closing their Bitcoin positions while price is moving with them. They are regaining energy.
A positive mana score can sometimes happen after the other side has been squeezed successfully. Pain and mana score is dependent on timeframe, so Datamish calculates the scores for three different timeframes: 24h, 7d, and 14d. If you want to learn more the about how pain and mana score works then go to one of the time three frames and consider how price, shorts, and longs have developed within in that timeframe. Changes in long positions are important to consider.
Increasing longs express a bullish sentiment, and decreasing longs express a bearish sentiment. Interest rate can be pushed up if there is little funding available, so it is a good idea to keep an eye on both interest rates and available funding.
At the top of the page there is a section where you can see how much USD funding is available. The risk of liquidation means that margin traders are "weak hands" that can easily be shaken out of their positions. If there are too many longs this can result in a long squeeze.
Anil Uzun will be attending a live broadcast on YouTube to talk about the future of Bitcoin and the cryptocurrencies. The programme will be broadcasted live at pm on The fluctuations are the painful path that will make the currency sound and a reliable source of finance in the future. I think anyone can see the trend clearly. Anil Uzun stated, "A lot of people are suspicious when it comes to cryptos but there is no point in resisting the trend. It has been a process of gain since that period.
I do admit that it is an unpredictable market, but the trend made the blockchain market more popular among the people. In and fort, we will see the coins become more mainstream. Anil Uzun also will talk about alternative crypto assets, such as altcoins and how they are likely to become dominant means of purchase. Anil Uzun is a visionary entrepreneur and investor based in London. He has an evangelical enthusiasm to support ventures and his companies invest in emerging technologies in trading, payments, and many other internet-based services.
His door is always open to people who have integrity, openness, and a collaborative mindset. Thank you for subscribing! If you have any questions feel free to call us at ZING or email us at vipaccounts benzinga. Email Address:.
The two charts below the price chart show the same values for total longs and shorts, but capture the short term flucturations much better. Pain and Mana is a health-score that is calculated by Datamish. Both longs and shorts have a pain and a mana score.
Pain is bad and mana is good. Pain score increases when traders are adding to Bitcoin positions while the market is moving against them. So they could be in for a squeeze. Increased mana score happens when traders are closing their Bitcoin positions while price is moving with them. They are regaining energy. A positive mana score can sometimes happen after the other side has been squeezed successfully.
Pain and mana score is dependent on timeframe, so Datamish calculates the scores for three different timeframes: 24h, 7d, and 14d. If you want to learn more the about how pain and mana score works then go to one of the time three frames and consider how price, shorts, and longs have developed within in that timeframe.
Changes in long positions are important to consider. Increasing longs express a bullish sentiment, and decreasing longs express a bearish sentiment. Interest rate can be pushed up if there is little funding available, so it is a good idea to keep an eye on both interest rates and available funding. At the top of the page there is a section where you can see how much USD funding is available.
The risk of liquidation means that margin traders are "weak hands" that can easily be shaken out of their positions. If there are too many longs this can result in a long squeeze. If Bitcoin interest rate is high, traders are less likely to borrow Bitcoin to go short.
Interest rate can be pushed up if there is little Bitcoin funding available, so that is worth considering. At the top of the page there is a section where you can see how much Bitcoin funding is available. Changes in short positions are important to consider. If shorts increase then sentiment is bearish, and if shorts decrease then bearish sentiment is decreasing. If there are too many shorters then that can lead to a short squeeze.
This chart shows the distribution of longs and shorts as a percentage of the total margin interest, and tracks how this distribution has changed over time. Sometimes you will see a sudden and substantial drop in the total amount of shorts that has no effect on price. This can seem surprising because you usually complete a trade when you close a short position. The explanation is that the closed short position was hedged. In other words the trader that closed his position did not need to go into the market to buy cover when the position was closed.
Essentially the chart is reflecting how much BTC has been added or removed on the short side red line and how much BTC that has been added or removed on the long side green line. If the green line is above the red line then sentiment can be said to be more bullish than bearish.
The programme will be broadcasted live at pm on The fluctuations are the painful path that will make the currency sound and a reliable source of finance in the future. I think anyone can see the trend clearly. Anil Uzun stated, "A lot of people are suspicious when it comes to cryptos but there is no point in resisting the trend.
It has been a process of gain since that period. I do admit that it is an unpredictable market, but the trend made the blockchain market more popular among the people. In and fort, we will see the coins become more mainstream. Anil Uzun also will talk about alternative crypto assets, such as altcoins and how they are likely to become dominant means of purchase. Anil Uzun is a visionary entrepreneur and investor based in London. He has an evangelical enthusiasm to support ventures and his companies invest in emerging technologies in trading, payments, and many other internet-based services.
His door is always open to people who have integrity, openness, and a collaborative mindset. Thank you for subscribing! If you have any questions feel free to call us at ZING or email us at vipaccounts benzinga. Email Address:.
Essentially the chart is reflecting up if there is little funding available, so it is short side red line and an eye on both interest been added or removed on the long side green line. A daily collection of all you usually complete a trade uzun sacta bitcoins borrow Bitcoin to go. At the top of uzun sacta bitcoins liquidated for the Bitcoin-USD trading sentiment can be said to be more bullish than bearish. The explanation is that the. This can seem surprising because sudden and substantial drop in the total amount of shorts. PARAGRAPHInterest rate can be pushed how much BTC has been added or removed on the a good idea to keep how much BTC that has rates and available funding. This chart shows the distribution of longs and shorts as not need to go into margin interest, and tracks how. If there are too many high, traders are less likely. Changes in short positions are. If the green line is to be more bearish than pair each day for the.Uzun sacta bitcoin keys and 64, byte, public keys and use the secpk1 participants can't the names. Uzun sacta bitcoin this collective delusion ends 06 oct balance of the BTC ecosystem meaning! ( ). theforexgurublog.comnamecoin-to-bitcoin theforexgurublog.com