For questions relating to the protocols by which crypto-currencies are transferred.

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7
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1answer
514 views

Why is Bitcoin defined as having 8 decimal places?

At the protocol level bitcoins don't actually exists, but rather base units (recently called “satoshis”). Bitcoins are defined as 108 base units, meaning that for a 50 BTC mining reward, you are ...
2
votes
1answer
23 views

How do I query a remote bitcoin node like RPC?

I know how to query the blockchain stored on my machine programmatically using bitcoind commands. Is it possible to do the same on a public node? For example, is it possible to send “getblockcount” ...
1
vote
1answer
33 views

Understanding Bitcoin protocol (through practice)

OK, firstly, Ken Sheriff (the guy who mined Bitcoin using pencil and paper) has posted some fantastic Bitcoin articles on his blog. In "Using Bitcoins the Hard Way" he writes (emphasis added): It ...
0
votes
3answers
64 views

Why block height is required in coinbase?

While reading bitcoin source I found this short comment: // Height first in coinbase required for block.version=2 (From https://github.com/bitcoin/bitcoin/blob/master/src/miner.cpp#L338). Why this ...
1
vote
1answer
38 views

Growth Dependent Block Size Limit

Could the 1MB block size limit be replaced with a growth-dependent limit? From what I have read (here, for example) the 1MB limit is to prevent spamming of the blockchain. And if/when Bitcoin becomes ...
6
votes
2answers
81 views

Is it possible to force a person to honor a conditional promise-to-pay?

I'm thinking of the situation where you have an auction where bids are placed. There are two conditions that should be held: Placing a bid shouldn't expose you to paying the seller unless you win ...
3
votes
2answers
67 views

Why is two hours the maximum acceptable offset for Bitcoin transactions?

As far as I understand, Bitcoin transactions include a timestamp, but the only requirement is that they don't differ for more than two hours. But why two hours? For computers that are constantly ...
2
votes
2answers
89 views

Can an output be spent in the block in which it is contained?

Is a Bitcoin block containing both a transaction that funds an output, and another transaction that immediately spends the same output, allowed by the protocol? Does such behavior occur "in the ...
2
votes
1answer
24 views

Maximum `getdata` message size

From the Bitcoin wiki's Protocol Specification page: getdata getdata is used in response to inv, to retrieve the content of a specific object, and is usually sent after receiving an inv ...
0
votes
1answer
33 views

Why does the script contain the hash of the public key

The ScriptPubKey contains the hash of the public key, and this is compared to the public key in the ScriptSig. It is not possible to derive the public key from the hash (address). But when the output ...
1
vote
1answer
110 views

What is the incentive behind using platforms such as XDP/Dogeparty?

ELI5: What can one do with XDP that s/he cannot do with DOGE? Is Dogeparty similar to projects such as Ethereum/Ripple? If I understand correctly one receives 1 XDP/1000 DOGE "burned". How are these ...
0
votes
1answer
20 views

addr_recv addr_from in version Message

I need some clarification about the meaning of the addr_from and addr_recv fields in the Version Message. addr_recv: The network address of the node receiving this message does this mean the public ...
2
votes
0answers
112 views

When spending a fraction of the coins in an address, can I send the remainder back to the same address? [duplicate]

Lets say an address has 150 unspent BTC, and I want to transfer 50 BTC to someone else, can I send the remainder (100 BTC) back to the original address? Is this impossible, a bad idea or something ...
5
votes
2answers
129 views

What is the reason for using PoW in bitcoin?

As we know bitcoin uses Proof of Work Concept and it introduces never ending long block chain and some other issues. Why is it not designed in a way to use consensus algorithms what ripple uses? What ...
0
votes
1answer
33 views

Can you put additional data in the payload?

It seems to me like you could put arbitrary data into a transaction payload, since it is JSON. Is this true, can a sender add additional fields to the transaction JSON? Or if thats not possible, could ...
1
vote
1answer
90 views

Explanation of what an OP_RETURN transaction looks like

How is OP_RETURN used and why was it introduced in the first place?
0
votes
2answers
55 views

How to properly use PreviousTxnID in a Ripple Transaction?

At the moment I am implementing a transaction overwriting with NOPs in Ripple. I want to store information about a transaction I am overwriting inside of the NOP. Looking at the PreviousTxnID field it ...
1
vote
0answers
32 views

Other ways to determine the validity of a public key

Public key 3, 4 fits the equation of y^2 = x^2 + 7 Yet this comes up as an "invalid public key". How is that invalid? Sure, it deviates extremely from other numbers, but what other equations are ...
1
vote
1answer
91 views

Ripple partial payments

I've read on the Ripple Wiki page for Transactions about partial payments. I am wondering how a partial payment would look when data is polled about an account? Would the transaction amount be ...
0
votes
0answers
25 views

Is demurrage already integrated into Ripple? If so, how does one create a demurrage currency?

The Ripple wiki has a page about demurrage currencies being a possibility in Ripple. However, it's not entirely clear whether this feature is already implemented in the server or client, and if so, ...
0
votes
1answer
30 views

Can a Ripple Transaction Sequence have gaps?

I am wondering whether a Ripple Transaction with a Sequence number that ships over a few numbers from the previous Sequence number be accepted as a valid transaction in the Ripple Network? For ...
0
votes
1answer
44 views

How does bitcoind find p2p hosts? [duplicate]

I read the bitcoin references but I can't find a description regarding how bitcoin clients find other host in the p2p network. Would you please tell me?
0
votes
4answers
81 views

Error compiling altcoin-qt for Windows, getting a GCC internal compiler error

I think I managed to get all my dependencies and libraries right (fingers crossed), but now when trying to build blackcoin-qt, the QTSdk compiler gives me this error while building qtipcserver.o: In ...
0
votes
0answers
26 views

GetBlocks Message containing Transaction Hashes

I'm sending a getBlocks Message which returns me an Inv Message containing up to 500 block-hashes as specified in the Protocol Specification. The Specification says: The maxium count for a an ...
0
votes
1answer
105 views

Programming and the ECDSA equation

I've been implementing point addition into a c++ program I've written but I don't see how this can be done right. When I do slope = (y1 - y2)/(x1 - x2) I get a freaking decimal, which doesn't produce ...
2
votes
0answers
178 views

Custom altcoin won't sync with node and neither will accept a miner connection

I forked the BlackCoin source, changed the ports, generated the genesis block, merkle, blah blah blah. I set up a node on a DigitalOcean server and compiled my coin daemon there as well as on my local ...
0
votes
1answer
21 views

What's the advantage of using non-truncated mining targets?

Bitcoin Wiki (Difficulty): The highest possible target (difficulty 1) is defined as 0x1d00ffff, which gives us a hex target of ...
1
vote
0answers
20 views

wireshark packet analysis missing checksum in version msg

I'm trying to send a raw bitcoin transaction through a raw socket connection in python. To debug I'm using wireshark to sniff the packets. Wireshark figures out that the packet is for Bitcoin and ...
1
vote
1answer
95 views

How to get the Z value aka Hash of the outputs to be signed

I get it that the "OP_CHECKSIG" does this, but I can't see how to recreate it. I tried SHA1 and SHA256 of some of the info in a given bitcoin transaction but it didn't give me confirmed values of Z. ...
2
votes
2answers
171 views

Bitcoin private key, location on ECC curve

In the ECDSA algorithm, the Bitcoin private key is supposedly a point on the graph (or is it?). But the private key is a single integer, and not x,y coordinates. Is the integer, by itself, the x ...
0
votes
0answers
46 views

Why ripple needs 80% of threshold in consensus? [duplicate]

Why ripple needs 80% of threshold in consensus? What is the mathematical prove behind that? Why not 66% threshold? Because i think 66% threshold in consensus is enough to validate a transaction in a ...
1
vote
1answer
85 views

Given the current hashing powers, what do pools actually do in practice?

Given the current hashing powers, what do pools actually do in practice to find a block? Ok, so here is my thinking, please correct me if I'm wrong anywhere: Here's the format of the block header, ...
3
votes
1answer
125 views

Ripple Distributed Consensus Algorithm

What kind of a Consensus Algorithms does ripple use? Is that a leader or leaderless distributed consensus algorithm? Then what?
1
vote
1answer
108 views

Why does Ripple needs to have a long ledger?

Why does ripple need to maintain a long ledger? Why is it not enough to maintain only the most previous transaction details? What is the purpose of having a long history ledger?
2
votes
0answers
44 views

Pros and Cons between Ripple payment verification and centralized authority's payment verification

I want to know the advantages and disadvantages between Ripple payment verification system and centralized authority's payment verification system.
2
votes
2answers
272 views

How do you get a Bitcoin Public Key from a Private Key (this is a NEW question)

How do I, in extreme specificity, convert a given private bitcoin key into a public bitcoin key (Talk to me like I'm 5 and I have to do this step by step or the evil witch will cook me alive in her ...
1
vote
1answer
78 views

Can I look for transaction in the genesis block?

I'm testing bitcoin and, as an experiment, I added a transaction after the coinbase to the genesis block. However, it appears that it can't be searched with the rpc commands. Why is that? I already ...
1
vote
3answers
82 views

How many bitcoin clones are out there? [duplicate]

How many bitcoin clones are out there? I mean people changing the name, the hashing algorithm and a few more parameters and creating a new coin that just keeps on copying bitcoin's source code in ...
5
votes
1answer
234 views

Transaction refund address

In the what’s new in Bitcoin Core 0.9.0 notes there is a reference to a refund address. I tried to look it up in the forums and the wikis but I came up with nothing. How can I set a refund address ...
1
vote
3answers
92 views

Do all Bitcoin alternatives need to have a coin limit?

In the Netherlands, it was just in the news the e-gulden was launched. Before we got the Euro (€) we had that currency in our country. An E-gulden (EFL) is currently 50 EFL = €1,50 But is there for ...
1
vote
1answer
37 views

Help with missing transaction

I'm trying to learn how to programmatically interact with the Bitcoin protocol. I've, seemingly, successfully generated a private key, WIF, and public address with code. I used Coinbase to send .001 ...
3
votes
0answers
59 views

How is the target section of a block header calculated?

I've been poking around https://en.bitcoin.it/wiki/Target and I've found the current target, but I can't seem to find how it's generated. It's supposedly generated when the difficulty is adjusted, as ...
2
votes
1answer
55 views

Has anyone attempted to rewrite the bitcoin software and protocol?

As anyone who has looked at the bitcoin protocol in depth can tell, it is really a huge mess of different encodings, hashing styles, and endian conversions. Although it would be a fairly cosmetic ...
0
votes
1answer
21 views

What are the pros/cons of changing the targeting interval (difficulty)?

BitShares is looking at using a target that changes every 24 hours. This is a drastic difference from Bitcoin's current interval of 2 weeks. What are the security implications that occur when ...
2
votes
1answer
51 views

Can I save mining fees when doing transitive transactions?

If I create two transactions: Send BTC from output X to Y, no fee is attached. Send BTC from output Y to Z, fee is attached (this depends on the previous tx). Would nodes propegate these two ...
1
vote
1answer
142 views

What are the weakest cryptographic guarantees in Bitcoin?

I read in this Github pull that Bitcoin relies on weaker cryptographic guarantees than SHA256. What are the weaker cryptographic guarantees being referred to? Could it be that RipeMD is 160 bits? ...
2
votes
1answer
117 views

How does the satoshi client handle endianness?

I'm looking through the source code of the satoshi client, particularly into how transactions are serialized and sent through the network or stored to the disk. The CTransaction class has this block: ...
1
vote
1answer
127 views

Bitcoin blockchain search algorithm and consistency policy

The blockchain looks like a double linked list, and all the transactions are stored into each block. What kind of algorithm does bitcoin use to find a specific transaction efficiently, since the ...
0
votes
0answers
41 views

Max number of transactions one node/connection can make to the network?

Just a quick question regarding the bitcoin protocol, I was contemplating making an altcoin for a school project, idea giving every possible address 1 coin to start, and people would 'mine' by ...
2
votes
1answer
51 views

Order of transactions within a block

Does the Bitcoin protocol guarantee that within a valid block, if transaction B spends the outputs of transaction A, A will always precede B? Or is it possible to have B before A?