Bitcoin Forum

The first selling point of bitcoin at bitcoin.org is:

"Instant peer to peer transactions"

But "1hour" to get at least 6 confirmations doesn't seem instantaneous to me, does it?

VISA-like transactions, that is 5-15 seconds, is what people regard as "instantaneous".

I don't get it. So please explain.

Imagine bitcoin gets popular:

1) You go to the supermarket or the bakery and pay with bitcoins...

2) You wait 1hour before you can go home???!!
Conclusion, will you never be able to use bitcoins on physical shops or when payment needs to be REALLY instantaneous?

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Another thing that is terribly slow is opening your wallet to take a look at it. If your wallet is on your pc, and you power it down every night at least, it takes 5-10minutes "to look what is inside your wallet".

That is TOO slow and also consumes too much disk space to be used on mobile phones!

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I think those the problems comes from the block chain design and the mining.

Don't get me wrong, bitcoin chain mining incentives, its security design and all make a lot of sense and its what makes bitcoin appealing; totally decentralized, limited coin supply, etc.

BUT, at the same time it seems the 10minute cycle, which is perfect for mining, is TOO bad for transactions.

Transactions usually are:
- Lightweight.
- Really instantaneous (<20seconds in the worst case)
- Once confirmed, they should not be reversible.

I know that bitcoin claims that transactions are NOT reversible, but that is also a half truth: only when the transaction is "quite" re-confirmed, it can be trusted have actually happened.

Please, let me know what I am missing.
How is bitcoin handling or will handle this issues?
I think these are really important to get right, specially if bitcoin ever grows up to be widely used just like VISA or paypal.

Should bitcoin provide a separate non-mining (not awarded) block chain for instant transactions (probably with bigger fees, although much smaller than traditional paypal or visa ones)?

The idea is that you create bitcoins just as you do now. It is ok to wait some hours or days for a new bitcoin balance to be "assured", but then you can move that balance to an "instant payment account" that will make transactions on a separate block chain designed for instant payments.

That block chain is just like the mining one, but it is just not rewarded with mining, or it is rewarded with just a really small mining prize  with a very easy POW that can be solved in 2-3seconds by the current bitcoin network power. Transactions that go there are confirmed in 12 to18seconds... THAT is instant payments!

What problems do you see in this approach?

Good post, the confirmation lag is one drawback of BTC.

For me BTC makes more sense paying online than paying in shops. Real cash is best in the real world IMO. Online stuff tends to get shipped, so there's a natural delay that can take care of confirmation lag.

You are making a mistake

Bitcoin isn't used for transacting, except for some occasional drugs

It's mainly used for hoarding and speculating that the price goes higher so rich miners can sell to poor suckers.

Ok, satoshi didn't mean that it would get used this way but it is, he can't stop it, muhahahahah

I'm accepting bitcoin payments on all my websites... cheaper than Paypal, anonymous and no chargebacks

Good for you

No one's buying tho

This would of course depend on why you want instantaneous confirmation.

The true nature of our impatience is that we live in a consumerism-based society which demands that we show everything we have now, Now, NOW!!!

If we slow things down a bit, we learn that the confirmation means that our funds are MORE secure, being difficult to steal or fraud, because there is no central authority which sits on its hands or issues a confirmation before it actually confirms anything (how fraud works in the fiat currency world). When we have a central authority which controls all of the money, it then also necessarily controls how that money may be used, and it creates opportunities for fraudsters.

To date, the only real issue with Bitcoin are the DDoS attacks on certain BTC-related web sites, which didn't succeed in taking any money, but instead cost the whole system some coins which may never be recoverable. It was the equivalent of trying to rob a bank, but accidentally setting the currency on fire. Overall, not a huge loss, financially, but it did cost the community a good resource.

Though I'm a newbie, I've been following Bitcoins for about the past 2 years, and I'm actually ready to invest a bit into the market.

And on my main website, I have a "donate bitcoins" button right next to the PayPal "donate" button (and since I live off of donations as a member of the clergy, in exchange for the work I've done, I'm happy to have a medium which is largely anonymous).

Yes, bitcoin is "fine" for most online transactions. But it would ALSO be better to have instant web payment confirmation.

Bitcoin is attractive NOW cause it is:

- WAY better that government controlled fiat money for hoarding and protection against bad government public administration (eternal deficits, privileged banking system, booms and bust cycles due to "descalce de plazos" = lending for years money that the bank may need to pay in hours or days).

- Easier to trade and secure than gold.

- Cheaper that Paypal or Visa for payments.

- Faster  (but not instant) than bank transfers.

But I think it should aim for instant payments (as it sells itself) and that is nothing against its basic philosophy, just a small mistake of the initial design and implementation.

A mistake that I believe can be corrected.

If bitcoin aims to keep as it is today, they should be honest and remove the "instant" word when they talk about payment, because it is a LIE if they don't change the design.

True, you've got to be mental to spend bitcoin in this bull market :D

Making a double spend is not an really easy task. Have you tried doing one yet?

At some Point Nodes won't relay Transactions anymore, that they consider double spends (or do they already?). A protocol will be implemented to for miner to consider fees on transactions that where send with an unspent output that is itself unconfirmed. Adding ways for a business to make double spend attacks on them even harder.

IMO, accepting unconfirmed transactions is generally save enough for anything except really expensive stuff (like buying a house, car) and high volume transactions with repayment (like gambling).

Try sending money overseas to your family members not using bitcoin, and you will start understand how usefull bitcoin really is, and the confirmation time will start looking as super fast.

I am sorry??
So you can waste 1hour of your time to buy bread of several hours on the supermarket checkout queue?
Good for you, you probably don't have anything more interesting to do or maybe you just don't need to work for a living!
But most people can't wait that long and it is not consumerism, is just like money always worked, many transactions need to be instantaneous.
PERIOD


Are you saying that WE cannot have a decentralized system THAT confirms my transactions in 12-18seconds instead of 1hour.
Interesting...
Why is that?
Why is 10 minutes such a magical timeframe?

Why 10, and not 5 or 20?


Nobody complained about that in this thread. I did not question bitcoin's security.
I just challenged its speed.


Good for you, I am 1 week into trying to get some TBCs and it will probably take me a month more to be able to buy some. It is too difficult and SLOW and there are many untrustworthy and greedy intermediaries. Just like in the fiat world or even worse.


Good for you again!
That use case is good for Bitcoin right now, and nobody here is trying to change those use cases.

What I am saying here is that either bitcoin should remove the word "instant" from their publicity or they should find a way to really allow "instant DECENTRALIZED payments" when they are needed.

I think that can be done with little redesign and cheap fees, more expensive than the traditional ones on the mining blockchain, but cheaper than those of Paypals, and VISAs.

Still 10minutes is way too long for some transactions.

A unconfirmed transaction is (nearly) instant.

The transaction is instant. I see it in my client within seconds of it being sent.

Confirmation is a little slower. I don't mind waiting a few minutes. It's better than what we had before Bitcoin and whatever replaces it will most likely be quicker.

Or you could stick with Paypal and not have to worry about how slow and terrible Bitcoin is.

+1 ^^^^
It's simple observations like this that show you haw important Bitcoin will be

Keep in mind you don't ALWAYS have to wait for 6 confirmations.

Nobody is saying that Bitcoin isn't a VERY GOOD idea...

It really is!!

What I say is that it could be fixed to be an EVEN better idea without losing ANY of its current uses and properties.

What you have to understand is that for something to be "a good money" it needs to be able to be used ON ANY KIND of transactions, not just one or a few of them.

Instant transactions (meaning in seconds) are too important NOT to support!

Otherwise another currency that can do what BTC can and ALSO supports transacting in half a minute will replace bitcoin in many uses and will devaluate your BTCs.

It's just like food stamps, if they can ony buy food there are less liquid, less useful that those stinky dollars or euros that don't have that limitation.

I know many think of bitcoin just as a niche currency & payment system, but to succeed even in being that it has to be tackle the decentralised instant payment problem or at least be honest about it and concede defeat, saying it is not really that instantaneous, just faster than traditional fiat based payment payments.

Right. for high value transactions, waiting an hour is no big deal. Everything else takes way longer than that. For low value transactions, you do not need 6 confirmation. Of course, faster wuld be better though.

Like Litecoin? It was released well over a year ago, I think.

Please, reply to this:

Are you (all) saying that WE cannot have a decentralized system THAT confirms my transactions in 12-18 seconds instead of 1hour.
Interesting...
Why is that?
Why is 10 minutes such a magical timeframe?

Why 10, and not 5 or 20?

Sure WE can. When are you going to design, code and release it?

The reason for the 10 minute time-frame is to decrease the possibility of miners solving the same block at the same time, potentially creating orphaned blocks. Currently, the average of the network is set to be 10min, however, you CAN get lucky, and solve the block in 1 minute. This IS happening. If the "time-frame" is too small, it means the window is too small, increasing the chances of orphaned blocks occurring.

Litecoin is 2.5min. This is a gamble, because miners who solve orphaned blocks don't get paid a fee. The risk of mining is thus greater. It's a trade-off.

Also. To add:

Unconfirmed transactions are nearly instant. If you are in a restaurant and you are paying someone (with say the wallet app), to pull off a double-spend is nearly impossible. This guy who is standing there is paying a small amount for meal. He then has to somehow have a mining pool at the ready (with enough hashing power) to quickly come in, and hopefully force a double-spend on a $20 meal. The incentive for the mining pool to do this is just so unfeasible, it's just extremely unlikely it will happen.

For low-value transactions, 0 or 1 confirmation is usually enough. In retail, a person is standing in front of you. For them to coordinate a double-spend is nigh impossible.

Well, not really, I could have a forged client that right before it sends a transaction, it sends a duplicate transaction to another address (of myself) in the background. On-screen it only shows the 2nd transaction.

However, even for unconfirmed transactions, double spending is very easy to detect. You can see the unconfirmed transaction appear in the network right away, and likewise you can immediately see if there were any other (also unconfirmed) transactions being sent from the same address(es). If they exist, and they exceed the total balance prior to the transactions, you simply refuse it. Can be done fully automatically.

In other words, if I were a retailer, I'd simply demand that Bitcoin payments are made from addresses that do not have any pending outgoing unconfirmed transactions that exceed the remaining balance required for their payment to me.

Instant payment FTW.

So first: get your blood pressure under control. I'm not really telling you how to live your life. What I am telling you is that your impatience today does little to change the way that a decentralized system in its infancy actually works. Getting impatient about it doesn't help matters at all--in fact, it doesn't bother me at all, since I'm not going to go pay 1 BTC for a loaf of bread any time soon (considering that today's prices would get me 100 loaves of bread).


So, first: you're taking what I said extremely out of the context it was offered. But let's look at the absurdity of what you're suggesting:

We can't scan bread in the middle of the store and take it home because there is no trust. Consumerism has caused the idea that such a resource is scarce, that it must be protected at all costs, and so people in Greece rioted when free bread was handed out. Is that the waste you're talking about?

Or how about the waste of spending 2 hours in a checkout line, when we should be able to shop all the way through and simply verify a purchase for the items... it would take almost the same amount of time (and could be streamlined over time, I'm sure), though the process would be a little more efficient and there would be less of a tendency for dishonesty in the supermarket. It takes only a change in the way we think about things to make anything work... so your little diatribe actually doesn't apply all that well.

When we build personal trust into a system, then stores can offer their own credit to customers who have built up a reputation--no need for credit checks, just look at habits, which we can easily look at within a given store. This allows for a social aspect of currency.

Patience is a virtue. It breeds trust. Trust, in turn, breeds speed.



Why would I say such a silly thing? I'm merely saying that being impatient about it doesn't help. If we had 3 billion people on this system, imagine how little time it would take to generate the confirmation. With more peers on the network, confirmation is a very simple matter, and will tend to take less time (not always, mind you, but in general).

10 minutes is an "average" under current conditions. In my own case, my first transaction took under 2 minutes. The bank transfer is still "pending" in my account, though the funds were already issued. How is that actually faster?


Speed reduces security. Security reduces speed. It's a computational rule.

Banks issue their money on my behalf because of trust. They know the money is there (they can see it). But they also want to give time for me to reverse the transaction. The banking system takes FAR longer than 10 minutes to actually transfer the funds (more like 2-4 business days); but because they are more established, they can issue funds based on the credited amount in my bank account.


BTC doesn't really have much in the way of intermediaries... EVERYONE is potentially an intermediary. The confirmations happen transparently, based on the block and share records stored at random in each client. Not a lot of room for lacking trust there, though I'm sure someone will figure out a way to (temporarily) break it sooner or later. Perhaps by "intermediary" you are referring to the exchanges?

But that's the beauty of open source software. Even if someone figures out how to break it, the community of programmers who maintain it will generally jump at the chance to fix the problems very quickly, and restore the system's trust



Bitcoin is not a company. That would imply a central authority who is "in charge" of the currency. It's the swarm that's "in charge" of it, not a queen bee.

Cryptocurrency systems are not overseen by ANY central authority. If anyone says "instant" then it's that organization or individual, not the whole world of Bitcoin. If you're dissatisfied with it, stop trying to use it to buy bread at the store.

You'd be vulneralbe to a finney attack. https://en.bitcoin.it/wiki/Double-spending#Finney_attack

Same problem with personal checks (regarding confirmations), yet many stores still accept them. Not everyone needs to operate on zero-trust, and that includes commercial operations. Paypal/CCs are reversible, cash can be faked. Bitcoin won't create utopia, but nobody in business thinks everything will be ideal. Shit happens.

Well said, sir.

Ok, this is the kind of response I was looking for, reasoning about design and its consequences... And replying to the post before this. I would be stupid to start to code something or even to purpose a new design BEFORE arguing with others more experienced in Bitcoin its possible pitfalls.

For a computer system 10 minutes is an awful lot of time, even 2 seconds is an awful lot of time. Computers lives in milliseconds, nanoseconds...

If the problem of that "instant transactions block chain" is just that mining would not be worth it, then we could just remove mining prizes altogether on that block chain. The incentive on that chain will only be transaction fees, the prices of "instant security" and for mining you have the parent traditional block chain that will work just as it does now.

As for the last part "Unconfirmed transactions are nearly instant./to pull off a double-spend is nearly impossible" doesn't change the fact that the restaurant or any merchant or receiver will probably prefer to have confirmation before letting the costumer go. The system should aim to provide that confirmation.

Another question, what is wrong with ripple consensus? (for "instant" transactions)

And, have you considered the scalability problems on 10 minute block transactions if bitcoin ever reaches VISA traffic?
Sooner than later bitcoin-qt will be made obsolete, at least trying to keep the block chain locally on a PC.
TODAY is ALREADY not feasible to have it on your mobile phone, you need to trust someone else service.

2000tps*512bytes= 0.97 megabytes per second (from here https://en.bitcoin.it/wiki/Scalability)
In 10 minutes that means that the block will be 0.5GByte, in an hour that means 3.5GB (more or less)... if your wallet was of for 24h then it has to download 84GB for each day offline!
You need a new HD every week! (with todays technology)

These are real problems to take into account.
(They can probably be fixed more or less easily, but first we need to accept we have them.)

The transaction time is related to the processing fee you offer, but yeah I think Bitcoin is too slow for over the counter.

Litecoin is faster and more likely to be every day currency.

Gold has a slow transaction time too, Germany will have to wait 6 years to get that transaction done with the Fed.  ;)

Theoretically, yes.

But this kind of attack would require an individual person to mine a specifically forged block (which takes extremely long, with today's difficulty), and then right at that moment, immediately double-spend the money at some retailer, before the rest of the network finds the next block. Seems like a *very* slim chance to me. Somebody would literally have to spend months outside a retail shop, trying to mine his specially prepared block, and then once he does, quickly go in and double spend some cash. Definitely not worth the trouble to buy some groceries or paying for a diner. As long as you require at least 1 confirmation for considerable amounts of money (e.g. buying houses or cars), I wouldn't consider this a real threat.

Corrections, is 6x0.5Gb is 3GB an hour and that is 72GB a day, still BIG!

Newbie adding to post count, blah blah been here forever regardless of what my timer / registration timestamp says.

Zero-conf transactions are fine if you are in a store, in person, and can show ID. If I were a merchant I'd accept that. I have means to seek restitution if the transaction fails. That takes seconds. Multiple confirmations are only necessary when anonymity is required, and/or the amount is large enough that it is reasonably worth it to attempt a "f2f con". So, buying a car, even with a gov ID, I'd still wait 3 - 6 or more confirmations, as a dealer, if the only identifying docs were your driver license or something. Luckily an hour isn't much time for buying a car... plenty of paperwork to do...

Instant AND anonymous requires some form of escrow / middleman / insurance setup. You know, like Silk Road already provides its userbase (unless you refuse to use it like an idiot).

Then there are things springing up like Ripple for quick, smaller transactions.

Cheers, welcome to bitcoinland.

So basically everybody here says Bitcoin as of today is SO perfect and doesn't need ANY improvement.
Not even if, being so perfect, it gets much more successful than it is now!

Very interesting...

I am know remembering that phrase from Mr Wolf at Pulp Fuction:
"let's not start sucking each other's d... quite yet."

No. It's perfect!  ;D

It's actually really hard to fake even one confirmation, and unless you are transferring large amounts of btc then it's almost pointless.

Lol. No, not perfect, at least not for everything. And there are still plenty of unknowns. We're in uncharted waters here... But, it is so far more or less the most perfect Bitcoin that has ever been. :p And, comparatively, it is also perfect enough that things have been only built to complement it, not replace or make obsolete. (LTC is "fairly stable", and Ripple as mentioned is one idea out there. They solve problems people WISH Bitcoin solved, but are fundamentally incompatible with Bitcoin -- in this case, primarily speed.)

SHA256 could get exploited tomorrow, for all we know. But even then I have a fair amount of faith that the dev team can patch in a replacement quick enough that it will only tank the exchanges for a day or so. It's definitely something they've discussed a bit.

I don't find bitcoin too slow at all.

It is not, for its current user base and use cases... but it might be soon if it is more successful...
and it is most certainly "NOT instantaneous", saying that would be a lie.

What I find interesting is that you continue to act like a troll (not that you are one, mind, but that several troll-ish behaviors are evident).

You take what is said and twist it out of proportion, out of context, and attempt a reducto-ad-absurdum dismissal to whatever anyone says.

You aren't satisfied with Bitcoin... so don't invest! Nobody's twisting your arm. You don't have a gun to your long-lost aunt Esmerelda's head while someone tells you: "So hop on de phone an' make a deposit."

Seriously, you aren't really trying to see any perspective but your own.

You want someone to pay for telling you it's instantaneous... the funds are instantaneously started, but unlike a bank there is no trust because there is security.

My credit/debit card isn't instantaneous.

In fact it takes 2-3 days to post.

I'd say bitcoin kicks the shit out of it.

It is because I find bitcoin interesting that I am here.

A bit of auto-critic won't hurt the community, but the absolute lack of it may...

Yeah right, try to buy in a supermarket or a restaurant. You can't wait 1h in a queue!

It won't happen, even if bitcoin success grows those use cases will still be out of its reach...unless it updates itself.

I was trying to discuss a fix, nobody discuses my design proposal, instead only say they don't need it...
ok fine!

It wouldn't so strange that tomorrow a new cryptocurrency arrives that gives you all that bitcoin does (it may start as a clone) and also gives you instant assured decentralized payments and your bitcoin suddenly is not the best available option.

Think a mixtere of ripple and bitcoin. That can happen inside bitcoin or ouside of it.
Which one do you prefer?

I personally think it's better inside than having to change cryptocurrency all over again.

Yes, definitely...I also noticed if you want your btc faster there's always more fees involved--not good as our incomes already gets taxed.  Its double taxation and dont even get me started on the rigged stock market! LOL 

Bitcoin is still in its infancy. As of TODAY, it is too slow for retail transactions like a grocery store. But if Bitcoin continues to gain acceptance, there will soon be a whole ecosystem built around Bitcoin. I can see merchant processing companies that will step in and fill the gap, to help process retail transactions instantly... and these companies will carry some burden of liability & insurance on their shoulders. It's really too early to tell what the Bitcoin landscape is going to look like in 5 years. Remember that when credit cards first started, merchants had to carry a printed, physical book that was updated every few weeks, that listed all the credit card numbers that shouldn't be accepted! Crazy, right? But that's how it was at the beginning. Of course, the credit card companies would honor the transaction for the merchant as long as the number wasn't listed in the book, so that was the merchant's protection. Someone will come along and offer the same sort of merchant protection for Bitcoin. That's assuming that Bitcoin becomes viewed as a legitimate form of currency by the mainstream, and not just a hoarding mechanism for speculative investors.

Aren't credit cards too slow to be considered instaneous?  Merchant isn't sent funds for 48 hours and funds can be taken back up to 180 days.
Both BTC and CC provide notification of a transaction within a few seconds.  BTC are confirmed in ~1 hour, CC are confirmed in 2 to 180 days.  Trying to execute a double spend in person in an environment where one can't guarantee execution time (like grocery store checkout line) is incredibly difficult.  Stolen credit cards can easily be bought online for far less trouble.

Still Bitcoin is a low level protocol.  It is highly likely that as long as Bitcoin continues to grow higher level services will be built on top of them including off blockchain transactions which can be guaranteed within seconds. 

"BitInstant". Everything is relative.

This is the point I was trying to make.

Thank you, that's what I was thinking to post while reading along the whole thread... I know that many Bitcoin fans have a different opinion about this, but I think we should really see Bitcoin as virtual cash or gold. It has the same characteristics as cash or gold (if you disregard that fiat money is being printed by central banks continuously) -- except that it is virtual and thus very easy to transfer and not completely instantaneous.

But the important thing is that just like cash, Bitcoin is low-level -- nobody is preventing anyone from providing higher-level services on top of Bitcoin, i.e. instant payment services. And these services don't have to become a centralized system -- just less decentralized than a real peer-to-peer network: there can be many instant payment providers without any central organization controlling them.

Btw, I also believe that Bitcoin has to become a bit less decentralized: if Bitcoin continues to grow that dramatically there is no other way than establishing Bitcoin provider businesses/services (like online wallets). A typical end-user won't be able to handle the traffic and resource usage of the Bitcoin network -- these tasks have to be transferred to providers. The no-trust system doesn't work in this big world -- it will be always necessary to trust some companies to provide some services. And as long the system is not fully centralized this is no problem at all.

It woul'd technically be possible. Look at litecoin which uses 3 minutes instead of 10 minutes.

That just means you get less valuable confirmations. The value of a confirmation lies in the number of hashes behind it. If you produce confirmations three times as often, they each represent only one-third as many hashes, so you need three times as many of them. It does, however, reduce the time to the first confirmation. So it can speed up low value transactions.

You say that as if you're the first to bring it up...

Here, some other stuff that people have brought up: https://en.bitcoin.it/wiki/Myths (https://en.bitcoin.it/wiki/Myths)

Really, you're treating this as if nobody's ever thought critically about it in their lives.

Litecoin is 15 mins.   Bitcoin is an hour.   We need something even lighter... a cryptocurrency with migh lighter-weight block targets in seconds.   I'm not certain chain length is the right way to gain consensus either.   The algorith ceph uses for consensus could probably e modified.   I think it's possible to get much more rapid peer confirmation, and I agree.... the first cryptocurrency that boasts rapid confirm times will be the one to win. 

Did you guy actually use Bitcoin only once to purchase something?

Go in an online shop and use it. It is instant. (There is no need to wait for that confirmations)

Next Friday might be a good opportunity to try it out.  ;)

If double spend risk is low enough, and it is, zero-confirmation transactions are fine. So..... instant. If you need to send considerable money.... wait it out. Then try sending the equivalent via bank wire, or similar, and see which was faster.

Buying online won't be a problem, buying in a pub or even a small shop might be.
I heard about a bitcoin accepting pub in London that had problems with iPhone users because the default setting was to send coins without a transaction fee, resulting in people waiting hours for their drinks...

Credit cards aren't instantaneous but are treated as such, but the get to the equivilent of 1 confirmation faster than bitcoin does.

What's done is done and you've already revived the thread. New users are reminded to please check the timestamp of the post they are replying to, to avoid necro'ing old topics. Nevertheless, welcome.

This is a topic that has been discussed endlessly, and will continue to be. Things to remember:

(1) With pure proof-of-work based systems like Bitcoin and Litecoin, it is confirmation TIME that ensures security, not the confirmations themselves. The 2.5 minute-average blocks of Litecoin are nice for providing network granularity, getting us to the initial confirmation faster, and for providing a higher capacity for transactions in the blockchain per unit time, but they come at a downside of increased odds of other things like orphaned blocks and other overhead. Decreasing the block interval further is not a good idea with a pure proof-of-work system.

(2) The thing people struggle with, presumably because it is math, is that, for a given network hashing power, 1 Bitcoin confirmation has the same security as 4 Litecoin confirmations. This can be calculated in the same way that Satoshi discusses it in his Security section (section 11) in the whitepaper. The only difference is the granularity, and increased overhead.

tl;dr - Faster block intervals is not the answer or we would have done it already. It just doesn't work that way with proof-of-work systems. I realize you technically are proposing someone create a faster one, not modify or fork an existing crypto, but I just want to emphasize the level of difficulty and where it exists, which is not in the domain of simply making a clone or a POW system with arbitrarily faster block intervals.

This is why bitcoin should be used for online shopping but supermarket shopping should fall to an alt coin like Zetacoin

zetacoin really is lightning fast... confirmations in seconds

This is where coinpayments comes in.. use fast alt coin that is stable to do small transactions and bitcoin with safer network to do large transactions.. why do u think alts are going nuts? it makes sense..

In the end an insurer can com along and grant you payments based on collateral which is your insurance premium. You pay and if it doesnt go thru insurance company hunts u down like credit card debt etc

That's not true.  As far as the transfer of funds, Bitcoin can do it within 5 seconds anywhere in the world.  It's the settlement part that takes confirmations.  Credit cards often take 30 to 60 days to properly settle a transaction.  It's possible for a meatspace vendor to accept zero comfirmation transactions at face value without much risk, due to the fact that a double spend attack while one is sitting inside a pub is very difficult, and that competing transactions on the network can be detected.  Timing is everything with a double spend attack, if the attacker sends the competing transaction too early, the vendor's client is likely to see it before the purchase has been made.  If the attacker sends it more than 5 seconds after the vendor's client does, it doesn't even matter that the double spend was even attempted, as no one will ever see it.  Also, if a double spend attempt is detected, the vendor could simply tell the customer his bitcoins have been denied in very much the same way that a credit card can be denied. 

While no one would be willing to accept anything less than several confirmations for something like a car, it's not unreasonable for in person purchase values of less than $100 at a time be accepted zero confirmations at face value, if the transaction is valid and no competing transactions (double spend attempts) are detected in the first several seconds.

Nope. Near-valueless confirmations in seconds. The probability of executing a doublespend with "Zetacoin" is the same per unit time as Bitcoin or Litecoin at a given hashrate. If you were buying a sandwich, Zetacoin would suffice (if it had the hashrate and therefore security of a mature currency). But one confirmation means nothing to me. I'd have given you the sandwich upon seeing the transaction at zero-conf on Bitcoin. One "Zetacoin" confirmation (target=30 seconds) means the same thing to me, probabilistically and from a merchant perspective, as this: 30 seconds pass by after you paid in Bitcoin, without me seeing a duplicate transaction sent to another address. We're 1/20th the way to a Bitcoin block, but from a security perspective, it is the same thing. At a given hashrate, the probability of faking 20 "Zetacoin" blocks is the same as the probability of faking one Bitcoin block.

Though since it has perpetual inflation built in, and is pure P-O-W, "Zetacoin" is more like the economics of PPC without all the other good and/or unique things Sunny put into it.

Sorry, Zetacoin has no technical merits, and many downsides (beyond just having no market share).

I would agree, still the advantages outweight the disadvantages imo!

Well technically it should be instantaneous, since you can see the transaction almost the second its sent, but you have to wait for it to confirm. Its kind of like my bank. When someone sends money its almost instant, but it stays in a pending state for a while.

Following up on my other reply as well: If the "Zetacoin" thread is any indication of real-world averages, mining "Zetacoin" results in at least 99% orphaned blocks, which is to be expected for such an idiotic idea as a 30-second interval (which isn't "seconds" anyway). That's how it works. The more you decrease that interval, the more you take from the Bitcoin, "one CPU one vote" concept, and start bottlenecking it with a huge caveat of, "if your internet connection is stable and fast, and if the majority of the network's connections are stable and fast" which makes it not nearly so useful. Never mind that with ASICs already in existence, they can easily attack or just take over the network at whim, since it's a SHA256 coin. Basically, this is one of the worst alt-coin implementations I've ever seen.

i have seen people talking about lots of orphaned blocks but this is not something I have come across when mining myself.  What alt coin would you recommend?

Either none, or maybe LTC and/or PPC. A little diversification is good and was always inevitable.

PPC has some unique non-stupid features, notably Proof-of-Stake, which is interesting. It is "inflationary" which I would dislike, but the inflation is pegged to attempt only to replace transaction fees, which are actually destroyed in PPC, not relayed to miners. In the end it would appear not to be inflationary. It also has a 10-minute block interval, because the PPC dev actually understands probability theory, I assume.

LTC has value because it uses Scrypt for hashing rather than SHA256, which has gotten some criticism because the NSA was highly involved in creating it, and the NSA makes everyone uneasy these days. The concern is they may have a backdoor or some secret knowledge of that particular function that enables them to take control or do something nefarious. Certainly within the realm of possibility, knowing how they operate. Who knows. (I wish Snowden would issue a statement positively indicating he was unaware of its compromise, or better yet that he is confident it is not.) PPC also uses SHA256, btw.

The 2.5-min interval of LTC isn't so short that it's downright stupid, like Zeta, but it's a bit shorter than necessary. 10 may be a touch long, maybe 5 is good, idk, but again, shorter intervals without some new innovation that makes it matter are useless, because it's time that matters, not confirmations themselves. Everyone just got brainwashed into "6-confirmations" without realizing the number 6 was a derivative calculation starting with probabilities vs. time, where Satoshi and the devs suggested 6 as an acceptable border for where confirmations can be considered "statistically improbable to reverse".

The rest of the alts offer no appreciable benefits, really. Jury's out on Ripple, it has some big backers, but I haven't analyzed it, and there seems to be a lot of money possibly skimmed to devs and people, not staying in-network. Not certain. It's an interesting idea, but until the day it's fully open source, I distrust it, and especially with it presenting itself with a name like "OpenCoin" when it is not (they now go by Ripple Labs, but still own the opencoin.com domain). I'd review this: http://ripplescam.org/ and vet things yourself before looking at Ripple. My gut doesn't trust it.

Conveniently, BTC, LTC, and PPC are the top-capitalized cryptos (if you ignore NMC). So the market knows best, too.

I didn't read all the post so I'll apologise if this has already been said.

The speed of you transaction is based on the fee you include to process it!

In the future businesses that want a faster transaction will have to bid a higher fee that others using the payment network.

This is how the network will fund itself after the coin reward is no longer a factor.

In the future we will also build infrastructure on top of the raw Bitcoin system to keep transaction numbers down so that people aren't paying fees in the single or double digit percentages for their bar tabs either. That's not much better than the world is now. Where a Satoshi is the smallest unit, sending less than 1 uBTC would necessarily equal a 1% fee, and increasing as the amount sent decreases. Today a uBTC is already about 0.11 cents (meaning 1/9th of a cent). That is already encroaching on the use case of microtipping and PPV web browsing unless bulk clearing methods are used. If 1BTC hits $1M, sending $9 results in a choice of either no fee, or a 90 cent fee. And at this point fees that small aren't really used for prioritization.

No, at that scale, something will exist on top of it, if nothing other than a PPC where P-o-S gains offset your burnt transaction fees, or. LTC's coin age for prioritization, etc. Or we see mining operations morph into something much leaner.

the random confirm times are annoying.
I love when they are every 2 minutes, but the flip side is the worst when a confirms are 30 minutes apart.

There are Bitcoin ATMs...how do they work to provide instant cash?

They quickly check the blockchain to ensure it isn't a "normal" double-spend and have your ID, so even if there is a problem (and really, the chance of fraud these days with the quick blockchain check is insignificant unless the ATMs accept 50+ $5,000 bills in a single transaction), they know who to sue.

Exactly. If you're really sophisticated you can make sure your client implementation connects to multiple network regions via some method. With the hashrate as it is, the network is over-secured at the moment. That's because of the block rewards, but as it tones down so will the mining. The average person, even a motivated one, will not pull off a doublespend with even 5 or 10 seconds of delay between transactions. A well-funded one has no reason to use $50k of equipment for huge preparation to pull off anything less than a big payoff, so you just calculate the risk vs reward and pick a safe zone, say ATM limits of $1000 between confirmations.

This myth is perpetuated by the main places we transact, like the exchanges, which still treat 100BTC and 0.1 BTC as the same thing, but at $120K vs. $120, those are obviously very different real-world security and fraud risks! At the current hashrate, a more reasonable method might be 15 seconds of delay for propagation of 0.1 BTC (reasonable at ATMs where it can use the time it takes to count out the cash internally to mask this delay), and maybe 3 confirmations for 100BTC.