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

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0
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1answer
22 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 ...
0
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1answer
24 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
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2answers
25 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
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0answers
21 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 ...
0
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1answer
39 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
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0answers
17 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
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1answer
12 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
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1answer
34 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
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2answers
39 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
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0answers
16 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
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1answer
90 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
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0answers
100 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
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1answer
18 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
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0answers
16 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
73 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
150 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
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0answers
45 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
84 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
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1answer
90 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
92 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
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0answers
30 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.
1
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1answer
161 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
60 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
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3answers
74 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
175 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
89 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
36 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 ...
2
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0answers
45 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
54 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
50 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 ...
0
votes
1answer
118 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? ...
1
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0answers
93 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
107 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
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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
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1answer
43 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?
2
votes
1answer
94 views

In what ways could “bitcoin” be hacked?

Dan Kaminsky said that he spent 4 months trying to hack "bitcoin" but failed. Besides trying to find vulnerabilities in double-spending and 51% attack, what other hacks would a hacker try to achieve? ...
1
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0answers
51 views

Transaction malleability and Bitcoind

I've been trying to get my head around the process that stops transactions from being malleable on a system built using Bitcoind. I'm pretty sure, that out of the box, right now, I'm not doing ...
3
votes
1answer
405 views

How is the transaction malleability issue being fixed?

With the upcoming release of Bitcoin Core 0.9, I am wondering how the transaction malleability issue is being fixed and what are the consequences of the fix? It appears that transaction malleability ...
0
votes
2answers
39 views

Fees/Taxes on Each Block Found

Haven't found a clear answer to this, but I have heard that various coins charge a sort of "developer tax". I've looked through a bunch of various crypto's sourcecode, but I haven't found any hints as ...
0
votes
1answer
64 views

What is the function of the payload_checksum field in the Bitcoin protocol

According to the protocol specification at the Bitcoin wiki, each message header includes the first 4 bytes of sha256(sha256(payload) as a packet checksum. I suppose this checksum is used for packet ...
1
vote
1answer
81 views

How was the new target for block 32256 calculated?

I'm trying to calculate the new target for Block 32256, but I'm not getting the expected result. Here's what I did: Timestamp of the previous block (32255) = 1262152739 Timestamp of block (32255 - ...
0
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0answers
64 views

JSON-RPC vs GETDATA, which is faster when fetching a transaction from your own node?

With the introduction of Bitcore, which makes Bitcoin a ton more accessible for Node.js, it's now possible to utilize the actual Bitcoin protocol instead of the JSON-RPC interface. So would it be ...
1
vote
1answer
43 views

Does the Bitcoin client not record original signature data per connection?

I just read the malleability page. Can someone confirm that this While transactions are signed, the signature does not currently cover all the data in a transaction that is hashed to create the ...
9
votes
4answers
195 views

Wouldn't the “malleable transaction” attack be foiled by common sense?

I'm trying to understand the malleable transaction attack, as it seems to me that only a rather careless operator would be vulnerable in the first place, as described below. Mainly to clarify my ...
3
votes
1answer
96 views

Why is an invalid pubkey accepted in the blockchain?

while trying to understand the address validation process, I fell upon this block : https://blockchain.info/tx/3d29f43a3278281192943276049c15e5f0d8c7e75d4d99a4cd6693113a948f48 In the outputs, the ...
13
votes
1answer
621 views

What is Transaction Malleability?

The Bitcoin exchange MtGox has stated in this press release that "transaction malleability" caused them to stop sending bitcoins. A recent question asked if it really is an issue. But what is ...
16
votes
3answers
3k views

Is this “transaction malleability” really an issue?

The well-known Bitcoin exchange Mt.Gox last week suspended all Bitcoin withdrawals because of "technical issues", which today have been better described in this press release. This looks like a ...
2
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1answer
171 views

Ripple network overhead

I like the way Ripple provides effectively instantaneous transaction verification. When building consensus how much traffic and their equivalent of orphan blocks are accumulated? Is communication ...
1
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1answer
126 views

Is Ripple's UNL list maintained by the network?

Who maintains the Ripple UNL list? This says We periodically poll our sources. If they mention a new node with a score over an amount, we add the node to our trusted core set. Who is "we"? Are ...