Questions tagged [timestamp]

Collects questions about the rules, precision, and utility of the timestamp in block headers.

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HELP ME WITH BITCOIN TIME STAMPS

OK, so I had several backed up .dat files on google which I put in opentimestamps I could see that these files had time stamp data... so I uploaded and *****below is what the results were. What does ...
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3answers
81 views

Is there a way to see the precise time of when a transaction was sent out?

I'm a developer. I'm not really knowledgeable in bitcoin development, yet. Say, I'm using Electrum wallet. I share an address with someone. The thing is that I need this someone to pay a certain ...
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1answer
55 views

Retrieve number of OP-RETURN transaction

Is there a possible way to extract the bitcoin transaction protocoll with Python and extract specifically OP RETURN transaction? I want to plot the number of those over the course of time to derive ...
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1answer
30 views

How to get the time when a block is received at a node?

Is there any variable in the bitcoind code that records the timestamp when a block is received for the first time by a particular node? To be more precise, for transactions, transaction information ...
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1answer
225 views

Bitcoin Pro API - How do you format start/end time for Historic Data?

I don't understand how to format the start and end time per https://docs.pro.coinbase.com/#get-historic-rates The sample time is "1415398768" which makes no intuitive sense to me, and when I tried ...
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1answer
38 views

When update mining difficulty, Is the timespan of the past 2016 blocks approximated value?

I know how to calculate difficulty, and I know it is increased or decreased by checking the timespan of the past 2016 blocks. and I found actual code for calculating timespan: https://github.com/...
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1answer
79 views

Bitcoind Testnet time/timereceived constantly changing?

I've got a small question: over a week ago I did some transactions on the Bitcoin testnet as I am developing a new GUI header for full nodes. When continuing development today, I noticed that when ...
3
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2answers
184 views

Block 620826 is 1 second before block 620825?

How does that happen? Obviously the miner of 826 built his block on top of 825, but why is the time 1 second earlier?
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1answer
72 views

What does best block time mean in wallet.dat

I have a wallet.dat file that states: Best block at time of backup was 42603 (0000000013136bd812212959a15ef0ea0f084ee2c64e2f7f0e127d198f67a37f), mined on 2010-02-26T00:36:08Z Does that mean that one ...
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2answers
2k views

Why the timestamp component of the block header?

What is the reason for the timestamp field in the block header? Surely the nonce should be the only property that changes? Should the nonce reset to 0 everytime the timestamp changes?
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23 views

Is it feasible to prove the density of found hashes and could that be valuable?

Background When a miner claims a certain hash power and timestamps a block they solved, they are making a claim that a certain amount of time has passed since they received the previous block. ...
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19 views

how the miner start to count the timestamp to insert in the block

I have a doubt, how the miner starts to count the timestamp to insert in the block. An example the timestamp insert inside the genesis block is 1/3/2009, 7:15:05 PM GMT+1. If the genesis block would ...
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2answers
479 views

Why does the median-past time average the last 11 block timestamps and not the last 12?

As described in BIP-113. Wouldn't the last 12 blocks bring us closer to a one-hour offset (ie 120min, midpoint 60)?
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18 views

TSA: Why singing hash(hash(data),t)?

Why does a TSA first appends the timestamp and hashes the combination of timestamp and data? This product is then signed and send to the client back with the timestamp. Why not signing hash + ...
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2answers
63 views

How does this time-stamping system work?

There is an online tool called Proof of Existence which uses the bitcoin blockchain to time-stamp documents. I'm reading the documentation but I fail to see how it works. I understand that it adds ...
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1answer
32 views

How do nodes come to consensus on whether a timestamp is valid?

From bitcoin wiki: A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. If a miner submits a block ...
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1answer
516 views

January 19th, 2038: RIP Unix Timestamps

Is there a plan in place for when the inevitable 32-bit overflow of Unix timestamps occurs? How much will this impact existing blocks that are timestamped with Unix Epoch times?
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2answers
4k views

The role of timestamp

In Satoshi’s original paper, it is written that “we need timestamp to prevent double-spending”. However, I think timestamp is unnecessary, because every block has a previous block hash and merkle ...
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1answer
1k views

What prevents similar time-warp attacks in Bitcoin as happened to Verge?

Right now (may 2018), Verge (an altcoin with proof of work) was attacked by time-warp attack. More can be read here https://blog.theabacus.io/the-verge-hack-explained-7942f63a3017 What exactly ...
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1answer
926 views

How to calculate block generation time from block's data?

I'm working on paper Double-Spending Attacks on Fast Payments in Bitcoin. And I see they give out the result : block generation time is approximately 10 minutes (9 minutes and 54 seconds), the ...
3
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1answer
860 views

How does timejacking enable double spending?

http://culubas.blogspot.com/2011/05/timejacking-bitcoin_802.html I went over this blog, but I am still not clear how double spending is achieved by this attack. From what I read, the attackers submit ...
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1answer
108 views

Network Time of Bitcoin

Bitcoin uses UNIX time for timestamp. Unix Time is really accurate. I want to know why there is a "70 minutes" offset is allowed in Bitcoin network adjusted time. Is there any distribution used to get ...
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1answer
487 views

From where does the 2 hours limitation on bitcoin time stamp come?

Bitcoin wiki says that: A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours My question is why 2 ...
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3answers
86 views

What prevents DoS based on near-valid block timestamps?

Upon receiving a newly mined block, the block timestamp validation is performed here: https://github.com/bitcoin/bitcoin/blob/master/src/validation.cpp#L3263-L3270 Q1: As for the second check (block ...
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1answer
586 views

How is PSZ Timestamp encoded in Bitcoin core code?

In Chainparams.cpp of the Bitcoin Core source, the encoded PSZTimestamp is as follows ...
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1answer
485 views

Rewriting the entire blockchain: is it possible to spoof block timestamps of a privately mined chain?

According to fork.lol and Pieter's bitcoin.sipa, it would currently take ~200 days for an attacker with 100% of the current hashpower to rewrite the entire btc blockchain. My question pertains to how ...
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2answers
58 views

What roles has the TIME information play in the bitcoin header?

What role does the time play in the bitcoin header? Is it ok to set it to 1 sec after the last block and never change it while calculating? Will the block be rejected when the gap is to large? If 2 ...
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1answer
98 views

Would mining future bitcoins break the bitcoin?

assuming an bitcoin miner with very much hashrate like bitmain would decide to mine "future" bitcoin blocks and provide them within very short time to the network, would this break the bitcoin? As i ...
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1answer
76 views

What is happening to the none approved transactions?

Every 10 minutes only 1MB of transactions are been approved, so what happened to the rest of them? Let's say my transaction was not entered into the block, can I be sure that no one is going insert it ...
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1answer
70 views

From the Whitepaper: Timestamps prove that the data must have existed at the time"

The whitepaper says exactly this: "The timestamp proves that the data must have existed at the time, obviously, in order to get into the hash. Each timestamp includes the previous timestamp in its ...
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1answer
816 views

Gaming the “off-by-one” bug (difficulty re-target based on 2015 instead of 2016 block time span)?

In this forum post from Gavin Andresen he writes: Second: I've written 'discourage blocks' infrastructure: https://github.com/gavinandresen/bitcoin-git/tree/discourageblocks (code reviews ...
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2answers
2k views

Are timestamps in transactions trustable?

I need to properly segment transactions by time. Are timestamps in transactions trustable? Can these be forged? I'm not sure if transaction timestamps are part of the protocol, but I'm particularly ...
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1answer
651 views

Ripple ledger time format?

I am wondering what is the format used in Ripple ledger time? For example, one of the most recent ledgers had close_time of 447299110. I initially thought it was UNIX time, but the current time was ...
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1answer
26 views

Are there performance implications using the “timestamp” property of ImportMulti in the following way?

Based on the Developer Reference for importmulti, it seems the the timestamp property is purely used to determine how far back to rescan. If I have, say, 100 addresses and I simply set all of their ...
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3answers
1k views

How accurate is Bitcoin network time?

Have any observations been made to conclude the accuracy of Bitcoin network time? It would be interesting to know if NIST or any other authority has tracked the phenomenon.
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2answers
2k views

How does Bitcoin figure out what time it is?

Bitcoin needs to know the current time in order to validate blocks. How does it decide that? Note that I'm talking about the Satoshi client specifically.
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165 views

What is the purpose of Bitcoin timestamps

Why do we even need timestamps on the blocks? Has it something to do with the consensus?
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1answer
278 views

How do nodes agree on timestamps?

While re-calculating the difficulty every 2016 blocks, how do nodes agree on the new difficulty? There is no unique timestamp on the p2p network, because nodes can lie about their time stamps. Let us ...
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1answer
64 views

Proving the margin of error of a block timestamp

In the Bitcoin wiki: Block times are accurate only to within an hour or two. is a bit vague. Is it possible to prove that an arbitrary accepted block timestamp is within x seconds of the real-...
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5answers
3k views

how can I insert an arbitrary sha256 hash into the blockchain?

If I want to prove that I wrote a particular document before a certain point in time, it would be sufficient to generate the sha256 hash of the document and somehow arrange for that hash to appear in ...
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1answer
2k views

Was a timejacking attack ever performed?

The timejacking attack appears to be a pretty straightforward attack to pull off successfully. I was wondering, whether it was ever performed and documented somewhere, or was it just theoretically ...
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3answers
4k views

What format is the time of a Bitcoin transaction stored in?

This may be a very simple question to answer, but I haven't been able to quickly find it. Regardless, if you were to deconstruct a transaction in the blockchain, and pull out the time value of the ...
7
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1answer
2k views

How is locktime enforced in the standard client?

I am trying to study the locktime feature of transactions ( https://en.bitcoin.it/wiki/Protocol_specification#tx ). I have created some raw transactions in the testnet with different locktimes, but, ...
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2answers
1k views

timestamp different block explorers are not the same

I'm kind of confused why the timestamp of a block is different when checking different block explorers. I think normally this is the time the block was found, no? So, when I check a transaction in ...
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139 views

Why do we need two transactions for CommitCoin scheme

I am studying BitCoin recently. I noticed a method called CommitCoin for secure timestamping. It requires two transactions to send coins back with the same randomness so that others can compute the ...
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2answers
234 views

Can a blockchain from the future be synchronized today?

If one or a few computers with blockchains from a future time line were connected to the Internet today, what would happen? This other question in Worldbuilding focus on possible consequences, but ...
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1answer
129 views

Why do testnet blocks have future timestamp?

I am playing experiments with testnet blockchain, and it seems like the best block is always set about 2 hours into the future. For example, now, the block has timestamp 90 minutes into the future. I ...
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0answers
75 views

Source for accurate block timestamps?

Is there a source of historical data which assigns a relatively consistent and accurate timestamp to each block? This might take the form of a server having precisely logged when they first heard ...
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1answer
2k views

where do the timestamps on blocks come from?

A stork brings them... or... One of the basic principles on a dist. system is lack of a global clock. So how are the timestamps assigned to blocks, by the machine that mines it? Couldn't it just ...
4
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1answer
2k views

How does a time warp attack work?

I more or less understand how an attacker (with less than 50%+1 of the hashing power) can artificially lower the block difficulty by messing with timestamps. I also understand how such an attacker ...