I think you are right. Good news. False alarm. I was basing this on an older description of Nxt. The code already removes effects of age on hashing power. Going to delete older posts. Specifically, I was confused by this: Alice has 2500 nxts on her account. Last time she found a block 4 days ago. Her money is like a mining rig with hashpower equal to 2500 * 4 = 10000 GH/s.
Bob has 1000 ntx on his account. He was on vacation and hasn't opened his account for 20 days. His money is like a mining rig with 1000 * 20 = 20000 GH/s hashpower.
But later BCNext says this (see below), which doesn't mention coin-age at all. So like you say he must have changed the spec. I was confused why he criticized PPCoin and ended up adopting an almost identical system. It would make a lot more sense if he dropped coin age altogether. It's a good chance to tell the details...
Each block has "generationSignature" parameter. An active account signs "generationSignature" of the previous block with its private key. This gives 64 bytes which are hashed with SHA256. The first 8 bytes of the hash gives a number (I call it a "hit"). The hit is compared to the current "target" (64bit number). If the hit is lower than the target then next block can be generated.
The target for each account is proportional to the balance. Someone holding 1000 coins gets a 50 times bigger target than someone with 20 coins. Thus the owner of 1000 coins will generate 50 times more blocks than the owner of 20 coins (in the long run).
The target is not constant, it grows each second passed since the timestamp of the previous block. If noone generated a block on the first second then the target becomes 2 times bigger and so on. The base target is the target on the 60 second mark. If there is only a few active accounts then after a long time someone will generate a block because the target will become very big. If you open the client and log with any funded account you can see a ticking timer in BLOCKS widget. It shows when the target will become greater than your hit.
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Did some more analysis. Nxt is vulnerable to a type of sibyl attack.  Will post the math later. Sorry I missed this earlier. Can we get the developer to rise from the dead so we can fix the mining algorithm? Edit: False Alarm. I was basing this on an older description of the Nxt algorithm. The algorithm has been changed. And this problem was fixed with the change. |
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This is my nxt account number:
12898636000396314855
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https://bitcointalk.org/index.php?topic=75029.0I don't think you can put micro-level decisions up to a vote and expect a good outcome. People don't have enough time to investigate every little thing. If most people abstain due to time constraints and ignorance, special interests will end up dominating the voting. That's bad for everyone. It would be better to elect a general manager and allocate a budget to him. If he fucks up, then his budget can get cut or he can be replaced. These are macro-level issues which it makes sense to decide by vote. I suggested this in the linked post in April 2012. It is still a good idea. Commentary: We have pools for mining, elected heads of state, and CEOs for a reason. Decentralizing every decision = a committee makes every decision. Ugh. Hierarchies are good too. They just need to be kept accountable.
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You mean "I managed to convince him to reveal some pieces of code right now and the rest in two months," correct?
What if there is a malicious payload hidden in the software? Bitcoin users are paranoid for a reason.
Correct. But stakeholders r supposed to vote if the whole sources will be revealed on the 3rd of Jan. They may decide to postpone that. Well, fast skimming thru the binary didn't show "wallet.dat" string  Got it. I advise everyone to run this on a low-value computer (something that you don't mind getting cryptolocked) or via the webclient until the source is released. Posted a thread for documenting answers to basic questions about Nxt. https://bitcointalk.org/index.php?topic=348625.msg3733803#msg3733803 |
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Question 1: What is the number of Nxt created at Genesis? (Appears to be about 1 billion units, but what's the exact figure?)Answer 1: [to be filled in] Question 2: Are there cents in Nxt? https://bitcointalk.org/index.php?topic=303898.msg3506162#msg3506162 This post says there should be.Answer 2: [to be filled in] Question 3: When will the nxt source code be released in full? Answer 3: [to be filled in] Post the answers I will fill them in and add more questions. Bolded Questions are not answered yet.
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He promised to release the source code in two months, correct? Could you convince him to do that now instead?
I managed to convince him to reveal some pieces of code. You mean "I managed to convince him to reveal some pieces of code right now and the rest in two months," correct? What if there is a malicious payload hidden in the software? Bitcoin users are paranoid for a reason. |
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As a preliminary measure, I stuck all posts in the nxt thread that are relevant to nxt's pos algorithm in a word document.
I stopped combing through the thread at the point of the nxtguy's disappearance.
I'm going to summarize this information in bullet point form in a new thread. I hope you guys can go through the bullet points to check for obvious inaccuracies.
Before i do this... Comefrombeyond, do any protocol modifications occur after the nxtguy goes AWOL?
Not sure. But I did see numbers like 1440 and 720 in disassembled sources. If u need to get answers, send me questions and I'll resend them to BCNext. Hurry up, I'm not sure how long it will take until he starts thinking that I'm a KGB agent. If he is likely to vanish completely, we should get our priorities straight. Forget about questions. We need the source code or the project is dead in the water. He promised to release the source code in two months, correct? Could you convince him to do that now instead? Or if not, could you get him to do the following: a) encrypt the source code and upload the encrypted file in some publically accessible location b) send the encryption key to a trusted third party. (e.g you, me, or anyone else) That way we can remain in buisiness after he goes silent. PS nxtguy, if you are listening, releasing the source code would reduce incentives to try to determine your identity. Both for the KGB and regular old forum users. |
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As a preliminary measure, I stuck all posts in the nxt thread that are relevant to nxt's pos algorithm in a word document.
I stopped combing through the thread at the point of the nxtguy's disappearance.
I'm going to summarize this information in bullet point form in a new thread. I hope you guys can go through the bullet points to check for obvious inaccuracies.
Before i do this... Comefrombeyond, do any protocol modifications occur after the nxtguy goes AWOL?
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-500K Nxt for a short video describing Nxt, it's green pure POS mining, the colored coins and decentralized p2p exchange features, internal messaging and decentralized DNS, instant transaction option.. all for a general audience.
-100K Nxt for a general article describing Nxt, it's green pure POS mining, the colored coins and decentralized p2p exchange features, internal messaging and decentralized DNS, instant transaction option..
-50K Nxt for the Chinese translation of the above article.
The initial deadline for the video bounty is 15th of December, for the article 5th of December and for the Chinese translation 7th of December!
To get the necessary info (general&technical) of Nxt for developing these projects, you can read the Nxt main thread mentioned in the OP or refer to Cunicula (who helped in debugging the scheme) or Come-from-Beyond.
I suggest splitting the article in to separate writing tasks. Also... video before article = cart before horse. I'm probably better qualified to write about the PoS design than anyone else because I played a role in its design. I'd expect a full 100k bounty for this, largely because I own no nxt. (Lack of gui, lack of whitepaper, need to use blockchain.info to purchase were too big of a barrier for lazy me.) I could do the chinese translation of my section too. I know nothing about nxt's other features. If you get one person to write the whole article, then the quality will suffer. That's not acceptable. Low quality article -> low quality peer review of nxt -> nxt underlying quality unknown (and best to assume low quality in the absence of other information) To facilitate peer review we need: 1) mathematically precise, approachable, and well-written article 2) nxt coders and third party coders to confirm that the source code does what the article says it is supposed to. Once those conditions are in place smart people can read the article and critique it. This process is essential for people to gain confidence in nxt (including me). |
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Thx for the link, this guy solution looks untenable for the reasons I described above, but he is at least on the same continent as I am in the goal he is aiming for. Well you might click on the link before arriving at a judgement. If you had, then you would have written "your solution" instead of "this guy solution." Or not, up to you. |
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But guys be fair in comparison Bitcoin will NEVER beat centralized systems for transactions. Decentralized will never beat centralized in number of transactions per second
Bitcoin wins epically in other aspects, just not this one.
I think you could approach the efficiency of a centralized system if you used a deterministic mining process. Then you could direct information directly at most likely possible next miner(s) rather than waiting for it to defuse through a network. It's still decentralized as long as the "known possible next miner(s)" are constantly changing over time. |
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I'm too drunk to critique this right now, but want to post so I remember to keep track of this.
The idea of mining empty blocks to improve security is an excellent one. The core benefit is that you can have extremely rapid confirmations w/o latency issues.
Will reread this later.
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How about this: Sunny King invented PoS, and in order to test this new concept he created PPC. In other words, PPC is not designed to be a currency. It is designed to be a proof-of-concept implementation of a PoW+PoS cryptocurrency. This, in turn, is the reason why PPC is not really being used as a currency. It is merely an object of speculation. https://github.com/ppcoin/ppcoin/wiki/List-of-services-on-market lists a meager total of 7 (in words: seven) "Shops, Retail Products and Services", which is absolutely ridiculous in relation the PPC's market cap. So, if you want to speculate in cryptocoins, buying PPC is as good a choice as any other altcoin. If you want to invest, then leave your fingers off PPC. Disclaimer: I do hold a few PPC myseld. Merely playing devil's advocate here... :-) Not true. Concept of PoS predates Sunny King (and me too). I first proposed using coin-age to determine PoS mining power (and also wrote the PoS wiki article on this and other issues) months before Sunny even started work on PPC and ~a year before PPC's release. I think the major question is not whether PoS is worthwhile, but instead whether we will see better implementations of PoS in the future. If someone doesn't offer a technical reason, then ignore them. If they say, invest in X because others are doing so or have done so, then ignore them. The way to make money through long-term investing is by evaluating underlying potential. Takeaway: For now invest in PPCoin, but keep an eye out for new PoS alternatives. |
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This thread is useless because people root for the coin they hold ... objectively though you should look at coins that do something new or fix something in Bitcoin that the Bitcoin devs can't.
In this sense even Litecoin's future is very dubious, let alone "Franko" & such.
I don't know a lot but from what I can see, Peercoin & Primecoin both do something new. The coming eMunie seems to as well, but I'm still studying it.
I agree with this. It doesn't make sense to select an alternative based on current adoption because bitcoin's advantage along this dimension is so overwhelming. The point of investing in an altcoin is to jump in before other adopters. If you want high returns, you need to anticipate adoption, not just jump on the bandwagon. If you invest simply because others have already invested, it defeats the whole point (i.e. you should just invest in bitcoin). Consider instead 1) differentiation 2) track record of developer 3) economic usefulness of the differentiating property 1) Peercoin (and its clones) & Primecoin have significant unique properties (not just parameter tweaks or new hashing algorithms). 2) Sunny King develops and maintains both Peercoin & Primecoin (he is the only developer (so far) who has released coins with significant innovative properties.) 3) Peercoin (and its clones) do not require expenditures on mining equipment and electricity; ultimately this means lower txn fees which is a major economic benefit. The only coin that satisfies all of the three criteria listed above is Peercoin. |
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Peercoin is the only coin with a legitimate value proposition (different security model).
All the other coins are either unfinished or extremely similar to bitcoin but just with weaker networks.
For now, peercoin and keep your eyes out for new opportunities (eg mastercoin if it suceeds in implementing some of its promised features).
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I wrote a whitepaper on Hop, but it was too hard to understand and too focused on details. To fix this I made a series of slides that focus more on explanation and the big picture. The slides illustrate Hop's motivation, compare Hop with real world analogues, and explain Hop's design choices. http://www.scribd.com/doc/186071279/Hop-System-for-Store-of-USD-ValueI would love to get feedback on the slides, so I can improve the explanation. Most of all I would love to get feedback on Hop, so I can improve the design! |
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