Bitcoin Forum

Every 3 days (on average) a block will take more than an hour to solve. Although 10 minutes is the average, occasionally it could be much more than this.

An hour is a long time to wait for a single confirmation, especially if Bitcoin becomes widely adopted.

It might not happen very often but this doesn't mean it's acceptable - ( once every 3 years a block will takes more than 2 hours to solve! )

I guess it's hard to propose a solution to this but could the difficulty be reduced (temporarily) if a block has not been solved in say, 20 minutes?

I realize that time is a fuzzy concept in the Bitcoin network so this might fall down if the nodes can't agree on what actually is 20 minutes.

 

Why is this a problem, exactly?

Even though that might be the case every 3 days, everyday we have most blocks found in less than 10 minutes.

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I've never really had an issue with confirmation times. OP's post is true that every so often there is that lull where it can take an hour to solve a block, but there are also those times where you will get 3 or 4 blocks solved in 10 minutes. So it goes both ways. At the finance company I work at, if the customer makes a deposit on a loan and then decides to back out we have to wait 7-10 days before we can refund their money since that's how long it takes the banks to process the check and find out if it's NSF or if there's a stop-pay. So the rare 1 hour block is still lightning fast.

No problem here ...

http://imagizer.imageshack.us/a/img901/5793/Tv94mS.jpg

It's not a huge problem now but imagine (maybe somewhat in the future) you paid for something in a shop of a significant value (say $100) in bitcoin and the vendor required one confirmation for payment to be accepted. Waiting 10 minutes wouldn't be a problem  but 1 hour or more would start to be really inconvenient. You could also find that so many transactions had built up during that hour that your transaction would be delayed by a block or two (even with a miners fee).

If bitcoin wants to replace existing payment structures then we want to think of ways we can avoid these delays even if they are occasional.

3 days ago there were 2 long waits within a 2 hour period

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I think Bitpay and the likes have sorted that problem, where you can do 0 confirmation purchases allready, so it is instant. We worry too much about things we get mixed up in terminology and their meaning. Blocks take time, it is part of the rigid state of the blockchain.

In the future you might not pay from your wallet directly, but through an other party, creditcard like. Or what other means we will have in a few years, there is a lot of tech in development at the moment to facilitate in the use of bitcoin. A lot of good things are comming, the chain itself is fine as it is, ten minute confirmation time on average is very fast in my opinion.

This could me more likely a time report delay in some pools or chart measurements it could variate for minutes or seconds, then again i see a lot of fast blocks under 11 minutes a part.

not a problem if you use offchain system or payment gateway like gourl.io for example, also the majority are moving toward online shopping and less toward real life shopping, where waiting for your purchase is less important

Is this the new trend-topic?
I just wrote in another thread:
https://bitcointalk.org/index.php?topic=1117697.msg11877497#msg11877497

People not understanding the tech, explaining that there is a problem.
As I already said in the other thread: The problem are the merchants, who just don't know best practice. There is just no need to wait for a confirmation, when other criteria are met:


(You know, you are getting old, when you have the same discussions with different newbies after a year or so ...)

It can't really be prevented. Due to the way that Bitcoin mining works, sometimes there are large outliers from the average and blocks are either found extremely quickly or extremely slowly. The "problem" can't really be solved since the mining is random.

This is just a natural result of probabilities.  Sometimes you will need to wait a few hours for a confirmation, and sometimes you will wait a few seconds.  As block confirmation times get further away from the 10-minute average (in either direction) the less probable it is.  Ten minutes is just the expected time to solve a block based upon difficulty as it relates to network hashrate, but there will always be some variance because solving blocks is a random process. If you want, you can transact in a currency with a shorter average confirmation time.  Litecoin's average block confirmation time is 2.5 minutes, but you'll still find occurrences where a litecoin block takes a half-hour or more.  It would be about as likely for a litecoin block to be solved in 30 minutes as it would a bitcoin block in two hours.

There are also coins which retarget difficulty much more quickly, but this tends towards network instability (i.e. the difficulty varies greatly, and accordingly so do the number of miners).

Its not a problem.  You check the mempool against other nodes for double spends.
Not sure if this is built into wallets yet but won't be hard when the market demands it.

I agree with you. When you pay with a bank card then the merchant instantly knows the payment is safe. It's not the same with bitcoins unfortunately.

Sure, merchants might sell on zero confirmations but it sounds like a risk when the network is spammed and someone sends a zero fee transaction.

And i was in the situation that i sold something and waited with the seller for a confirmation. It's no fun. Especially when the seller needs to get his train or something.

If possible, a solution here would be nice.

Don't send a zero fee transaction. I think, they will disappear anyways(I still send them sometimes).
There are some factors you have to look at, so you could also accept a 0-confirmation transaction without having to worry.
And all the people, who tell you how easy it is to double spend with a 0-confirmation transaction: They are full of shit. None of them ever showed any proof of that.

You are kidding right ?

This is not true.  The merchant does not know that the payment is safe, instantly or otherwise.

I am familiar with a website that accepts credit cards and provides music downloads.  When the credit card processor gives preliminary approval the web site enables the download. Rarely, a fraudulent or dead-beat "customer" can complete his download before the credit card processor revokes the preliminary approval.  The web site never gets the funds, but the customer has the electronic goods. With this credit card processor it is possible to reduce the probability of loss by waiting longer, but this takes several hours (and there is still a charge back risk).  The website owner made a business decision to deliver the goods immediately, for customer convenience.   So far, this has proven to be a good decision.

How is this different from accepting bitcoins  with zero confirmations?

No.

There is no problem. Bitcoin is censorship-proof money. It solves problems which other forms of money can not. It also comes with costs that other forms of money do not have (like understanding how the block chain must be built and accepting confirmation times).

Bitcoin is only a tool and tools are normally specialized things.

When you need to cut a piece of wood, you don't grab a hammer, you grab a saw.

When you need to permanently transfer value without the help of a middleman or the permission of an authority, you use Bitcoin.

When you need to buy some cheap mundane consumer good in a store, you use a credit card, debit card, fiat cash, paypal, et cetera.

Bitcoin can not be all things for all people. People need to accept that instead of trying to change Bitcoin (which has certain properties unlike any other form of money on the planet) into something else (for which we already have multiple, perfectly functional options).

Confirmation times exist due to the very nature of how Bitcoin functions. Anyone who thinks they need fixed isn't bothering to look at the big picture. Do you want Bitcoin to allow you to easily buy your junk, or do you want it to continue to provide you with monetary freedom? Which of these things does the world desperately need, more consumers or more freedom?

Sure, that is what off- the chain transactions are for like circle/coinbase/changetip are for, Payment processors like coinbase and bitpay are for, and soon to be introduced interchannel payment systems like impulse and lightning network are for.

My point was more about the merchant being at risk. I mean you say, correctly, that transaction might get lost. But there are payment services like bitpay.com that accept a payment after it shows up on the network, they don't wait for a single confirmation.

Probably that is something good for adoption, since people have a good experience and it would no make sense for them to wait for, maybe, an hour. But i don't see how the risk of that payment not going through can be covered by bitpay.com. And they are responsible against the merchant when they payment doesn't reach with them.

You are right... the transaction could come from a carded credit card. So the transaction will be charged back when the real owner sees it.

The only difference would be that you have at least some details, like IP or so. Though it's open how far you can go with that.

With a clever carder you probably won't have a chance. I wonder why scams not happen more often since you sound like the risk is very small.

YES! Let's crowdfund for a dictionary that'd include an updated definition for the term 'on average'.