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Questions tagged [timestamp]

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

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9 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
113 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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1answer
14 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
781 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
44 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
255 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
64 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
407 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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2answers
280 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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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
59 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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2answers
55 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
72 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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2answers
2k 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
374 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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1answer
62 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 ...
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60 views

OTS - Can't find Bitcoin block!

Hoping for your answer, I’m writing you my question, since I’m not coming any further since a few days. I’m getting following error-msg when I try to verify my ots: Assuming target filename is '...
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1answer
60 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
24 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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157 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
178 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 ...
2
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1answer
681 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 ...
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1answer
44 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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2answers
743 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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1answer
108 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
209 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
109 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
63 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 ...
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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 ...
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1answer
642 views

Bitfinex get credits and convert timestamp to JS Date

I'm fetching my active credits in BFX and trying to discover when I'll have my funding back. This is a response example: /v1/credits [{ amount: "294.4316181", currency: "USD", id: ...
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1answer
82 views

Is there a way to get the node's local time when a block was received?

As in, not the miner's timestamp in the blockheader which can be +/- 2 hours, but the receiving node's local time. My concern is the real-world time that elapses between blocks.
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1answer
72 views

Finding the timing of blocks, afterwards?

I understand that the timestamps on blocks are not fully accurate. Given only that information, it's efectively impossible to do retrospective analyses of timing of blocks. (For example, this; http://...
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2answers
337 views

Is Bitcoin a decentralized time-stamping authority?

Can Bitcoin/blockchain be thought of as a decentralized time-stamping authority (TSA)? Is there true consensus in the Bitcoin network on a mined block's time, or just that the block was mined?
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283 views

Using the blockchain for providing other services, besides bitcoin transactions

What I have in mind are proof of existence software, than are a kind a non-centralized and virtual notary service. They time-stamp digital information submitting a hash to the blockchain. I know ...
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2answers
636 views

blockchain.info transaction timestamps set into the future

There seem to be some irregularities with Blockchain.info's transaction timestamp (aka Received Time) for a set of blocks. The transaction times are recorded with unix timestamps well into the future ...
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1answer
150 views

bc.info transactions with no timestamp

The last transaction in blocks 219882, 219888, and 219892 don't have a timestamp. And by last transaction I mean the last transaction shown in the json file. 219882 219888 219892 I find this to be ...
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2answers
794 views

How could a time warp attack be prevented?

jarpian explains what a time warp attack (AKA zeitgeist attack) is: This is a 51% attack where the attacker sets the block timestamps artificially to lower the difficulty, allowing him to profit ...
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2answers
178 views

Why use OP_RETURN for long-term timestamping if they are pruneable?

There are some timestamping services such as proofofxistence.com that use OP_RETURNS transactions to store a document's hash, so in the future a 3rd party can verify the existence of the hash (and the ...
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1answer
347 views

Is the block timestamp reliable enough to timestamp the hash of a document?

In using the blockchain to timestamp the hash of a document, so to prove that it existed before a certain time. Is it reliable? Do you think it can stand on court? (IANAL and probably you neither) ...
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216 views

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

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 ...
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2answers
3k views

How do we check the time when a transaction hits x confirmations?

Consider the transaction 948a427.. which has 3341 confirmations as of now: We can see that the time the relay is received at 8:36:30 and it has one confirmation at 08:50:04 (after 14 minutes). How ...
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1answer
48 views

How exactly is network time sampled?

How exactly is network time sampled? Is it as simple as one node stamping data right before being sent, the receiving node logging the current time before all other activity, and taking the ...
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1answer
452 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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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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1answer
210 views

Can an old block be inserted into the blockchain?

I've been shown how network time is enforced, but I'm still having trouble understanding how a false old block cannot be inserted into the blockchain with the entire chain remined or how a powerful ...
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1answer
281 views

How is network time enforced?

I've seen how nodes gather network time data, but how is it enforced in the blockchain? Are all of the timestamps digitally signed and included in the block as proof?
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1answer
441 views

Are transactions verified in chronological order?

I've seen that blocks include timestamps which are updated "Every few seconds", but who updates the timestamps, and are the timestamps used to verify transactions in chronological order? If a block ...
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0answers
728 views

p2pool no payment since 60 hours

i installed a yacoind and yacoin-p2pool on my server and starting mining yacoin with other people, since 60 hours of non-stop mining no one in the pool got a payment and people started to complain! i ...
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2answers
1k 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 ...