11

Assume for a second that we found a proof of work algorithm that had all of the good properties of sha256, but was also useful for SETI and maintaining world peace. Now suppose a group of miners collectively have more than 51% of the hashing power. In which of the following scenarios are they more likely to collude to double spend via a 51% attack: A) When ...


11

If scripts were Turing-complete, you could construct a fairly short script that took an extremely long time to run (a la the Busy Beaver) or contained an infinite loop. This would tend to result in a denial of service against everyone on the network, when they tried to verify the transaction. And there would be no general way to tell whether a script ...


10

A Bitcoin or Litecoin address consists of: a prefix byte a 160-bit hash of a public key a 32-bit checksum all base-58 encoded. Bitcoin and Litecoin use different prefix bytes; this is why most Bitcoin addresses start with 1, while most Litecoin addresses start with L. When you use a Bitcoin client to try to send money to an address, it should perform a ...


9

99% of altcoins claim an "innovation" that is broken or unproven. I would say that the first thing to do is look at unique codebases that aren't based on Bitcoin, which basically means (besides Bitcoin) you should look at Ethereum, Ripple, NXT, Monero, BitShares. Then if you're bored, PeerCoin / NuBits and Lisk. Once you are done with those you can look at ...


8

Nothing stops this at all. You can start your own right now, removing the 21M limit or adopting whatever rules you want, and mine as many coins as you like. Likewise, you can sit down at your printer, and print lots of $100 bills with your own portrait, and invent whatever rules you want as to how they can be spent. The question in both cases is whether ...


8

This is really asking about basic trading economics: if I have some new product X, what price does it have? I can set a price and see if anyone buys it. If not, I might lower the price or auction it to see what someone might pay for it. That is the starting value, but it doesn't really mean much as it hasn't been field-tested (so to speak). If others think ...


8

But then the next problem is transaction order and validity to prevent double spending. I don't understand completely why a timestamp can't just be included for every broadcasted transaction, and the transaction could have the correct, universally agreed upon time, and each ledger gets sorted chronologically. Is this because it requires a centralized system ...


7

Well, Litecoin's main aim is to make mining easier for the common man. The problem with pure SHA-256 mining is that it is not very hard to design hardware that can perform mining at an astonishing speed. We can see this with the currently very much ongoing rise of the ASIC mining industry. Since scrypt is more complex when it comes to hardware - scrypt not ...


7

Proof of burn simply means you have provably destroyed coins. The only way to destroy coins in a proven way is to send them to an address which is improbable to have been generated from a private key, and thus can not be spent. Chancecoin is the first I've seen to use this way to generate their coins. The announcement for Chancecoin can be found here: https:...


7

Contrary to the name the proof of work used in Litecoin is significantly more difficult than SHA256 to verify (it slows sync times noticeably), while simultaneously not achieving it's goals of being only able to be mined on a CPU, or a GPU depending when you read the pitch on their website. It offers very little resistance to being mined on a GPU or ASIC, in ...


7

A very large majority of these altcoins are essentially scams. There is a cottage industry that takes a coin, changes something minor (name, logo), and releases it with great fanfare, enticing people to buy it, allowing the forker to unload their typically worthless coins. As Нонн Болдырев said, there is a small list of worthwhile coins. I'd leave Ripple ...


6

Litecoin is the 2nd most popular currency in the same family as Bitcoin, and: It is based on the Bitcoin protocol but differs from Bitcoin in that it can be efficiently mined with consumer-grade hardware. Litecoin provides faster transaction confirmations (2.5 minutes on average) and uses a memory-hard, scrypt-based mining proof-of-work algorithm to ...


5

Even if the dynamics are interpreted in the most basic way, it does not lead to this positive feedback, rather it maintains the status quo. If there are miners with stake of 40%, 30% and 30%, they will get 40%, 30% and 30% of the rewards respectively, so the ratios will remain at 40%, 30%, 30%. For example, if they start with 40, 30, 30 BTC, and 10 new ...


5

According to these lines an accountId seems to be... int(sha256(publicKey(sha256(passphrase)))[7:0], 256) ...which translates to 256^8 accounts or roughly 2 * 10^19, which fits the idea of around 20 arabic numerals. Given there are only 2^64 unique accountId and the birthday paradox, you can check this collision probability table (the 16 bytes/64 bits row)...


5

The shorter the blocktime the more time is lost by the relaying of blocks in relation to the average blocktime. A very short block interval therefore makes SPV mining (i.e. mining empty blocks without transactions) more attractive, and increases the advantage of large pools, because they can start mining on top of their own block the quickest. Additionally, ...


5

If NXT is switching to Ardor, what is the purpose of holding NXT? Nxt isn't switching to Ardor. It will still exist after Ardor launches. The purpose of holding NXT with this in mind is if you need to use the Nxt blockchain, either for personal use or projects, since one will need NXT for the transaction fees, etc. Another reason could be the speculation of ...


5

Blockchains are not really scalable. For the most security, blockchains need to be replicated on as many devices as possible. Those devices are full nodes and must download and verify every single block and transaction. In order to increase the number of transactions, transactions have to become smaller and blocks have to become bigger. Unfortunately ...


5

But then the next problem is transaction order and validity to prevent double spending. I don't understand completely why a timestamp can't just be included for every broadcasted transaction, and the transaction could have the correct, universally agreed upon time, and each ledger gets sorted chronologically. Is this because it requires a centralized system ...


4

Yeah it's called buttercoin here is their code.


4

Peatio is an open source crypto exchange. Their README says: Peatio is a free and open-source crypto currency exchange implementation with the Rails framework and other cutting-edge technology. Mission Our mission is to build the world best open-source crypto currency exchange with a high performance trading engine and safety which can be trusted and ...


4

Bitsquare.io is currently the state of the art and it is open source: https://github.com/bitsquare/bitsquare/


4

Yep there are three good options for CPU mining that I know of: XPM: PrimeCoin QRK: Quark PTS: Protoshare - very very new and exactly what you described. Google search those and you'll find plenty of info. Seems like there was a fourth but I can't remember it off the top of my head.


4

This is possible through the use of a multiplier. For example, you could add it to Bitcoin as follows: You add a "currency multiplier" and "next currency multiplier" to the block header. All Bitcoin amounts presented are multiplied by this multiplier. You have a set of rules for how the next currency multiplier changes. For example, miners could be ...


4

This is basically how every asset in Ripple works, other than XRP. Ripple permits anyone to create an asset and back it in any way that they choose. Others can declare their willingness to accept specific assets in payment. And Ripple implements distributed order books, payment pathfinding, and atomic multi-asset transactions to implement transfers of value....


4

Here's one way I found. Get pywallet (https://github.com/jackjack-jj/pywallet) and run python pywallet.py --dumpwallet --wallet=/foo/bar/wallet.dat Look in the output for a field called names. This will contain a list of addresses in the coin's own format, and by looking at the first character you can try to identify the coin by its version byte. See ...


4

If an online store accepts another crypto-currency appart from Bitcoin, you can be sure 90% of the time it'll be Litecoin (most accept just Bitcoin as of now). It's the one that has the 2nd biggest market capitalization and market depth as well. As to what could be the 3rd most popular, that's difficult. "Popularity" is difficult to measure directly, but ...


4

Currently, Ripple Labs runs five validators and most Ripple servers have only these five validators on their UNL. A transition is in the works to distributed community management of UNLs, and that transition is expected to be completed during the first half of 2014. In the final scheme, publishers will be able to publish lists of validators (by public key). ...


4

When building consensus how much traffic and their equivalent of orphan blocks are accumulated? Once a consensus round starts, the amount of information that needs to be distributed is fixed, since new transactions cannot be introduced. If there's no reason a transaction shouldn't be included, then almost all honest nodes will ask that it be included. If ...


4

I agree more context is needed to provide a more directly meaningful answer. But in general: a blockchain allows users to interact without trusting a central authority, instead they verify the system’s state on their own. As a user, I can verify that I own some amount of bitcoin by running a node, and seeing the transactions that paid me as confirmed in ...


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