Bitcoin Forum

Optional reversibility at least.  I've heard a million times on these forums that third-party services will offer the needed features that consumers desire.  The more features that are built into the protocol, the less reliant we will be on those shady centralized services that want to "know us", hit us with fees, or just Gox us.

Here is the concept.  It's probably been discussed and dismissed already, but here it is anyway:

You would be able to predesignate an address as a reversible address.  Two variables would need to be set, the block-depth of the reversibility and the address to which any reversed funds would be sent to.  Since an address doesn't exist on the blockchain until at least one satoshi is sent to it for the first time, you would have to send that first satoshi along with the proper reversibility instructions to setup the address.

After the one satoshi spend was confirmed, you could verify on-chain the reversible properties of the address, which again, would be the block-depth of reversibility and the go-to address of any reversed funds.  You could proceed to load up the address with coins.  Spending would be as normal for the owner.  It would be publicly verifiable that any spends originating from for such an address would be reversible until they were 'X' blocks deep in the chain.

If you spent reversible coins and wanted to undo the transaction, you would have to broadcast a new transaction and have it confirmed in the chain before 'X' blocks had elapsed.  In order for that new 'double spend' to be valid, you would have to direct the funds to the same go-to address originally specified when you set up your reversible address.

The point of having a designated go-to address be different from the originating address is in case your private keys were compromised.  You would still be able to undo the transaction, as would the attacker.  But unless they were in control of the second address as well, they wouldn't end up with the coins.

There could be an upper limit to reversibility, perhaps a month.  There are pros and cons to encumbering your coins as such.  No vending machine would accept coins that could be reversed.  But an internet retailer would, they would just need to wait X blocks + 6 confirmations before shipping your stuff.  The nice part is you could get the email receipt from them that you paid and all was good before the reversibility window had passed.  If you didn't get the email, maybe because someone had man-in-the-middled the merchant's address, you could fix the mistake before it became permanent.

Lame..

BTC transactions are not reversible.
Simple beauty is good.  :)

Just lost all respect for OP.

Reversibility is a fallacious idea. The only reason we have reversibility today is because the huge banks aren't afraid to steal from a legitimate business when a customer wants free goods or services.

Reversibility is terrible if you've ever been subject to a charge back. Even when you follow every step required to protect yourself, you're still unlikely to win a charge back request. The CC company has more to gain by awarding in favor of the customer than the merchant.

Bitcoin will not have reversibility. If you get scammed, be more careful next time, and take the scammer to court. Get a judgement, garnish wages, take liens on personal property, etc... Bitcoin reversibility is not the answer.

Reversibility creates new victims, the scammers don't usually lose a dime.

Transaction reversibility will eventually happen with Bitcoin, when a wider adoption to the masses occur. But, the reversibility will only take place with 3rd parties that transact your Bitcoins, kinda like how a credit card company works now.

When all this happens, Bitcoin will become more and more centralized and become less appealing to the underground audience, but really appeal to the consumers.

All that will effect Bitcoins price.

Yeah and then slow down the transactions while your coins/ funds are in limbo. No one likes to buy BTC at exchanges sometimes if it not instant.

I disagree, the third party won't have any control over the protocol. They could theoretically create an alt and then back it with Bitcoin, but Bitcoin will never be reversible.

It's unfair for an organization with a vested interest in their customer to have the unilateral power to rob a third party merchant of money received for legitimate goods or services... It's not a good system now, and it wouldn't be a good system for Bitcoin where there is practically no oversight on the decision-making.

If you can't live without transaction reversibility then I suggest you stay away from gold, Bitcoin, stocks, and financial investment in general... Bitcoin isn't alone on the block without it, and it's not an attractive attribute anyways.

Why not just have the person send back the coins and reverse it manually. Then u don't have to change bitcoin

Just bring back the practices of down-payments, deposits, and escrows. They are from back before a bank could just print more money and cause inflation. They worked fine. Bitcoin puts them on steroids.

i dont think that would be a good idea  ::)

I don't know if most of you even read what I wrote.

This would not alter the ability to send irreversible transactions.  That is one of the main reasons bitcoin is so powerful - I agree - and it seems most of you do to.

The point of this would be to add functionality.  It would add to bitcoin.  Could you please be more clear what you think it would take away from the system?

Keep in mind that every client and wallet would be updated.  If you received a reversible transaction you would be notified as soon as it was detected that it was reversible and you could act accordingly.

Obviously exchanges wouldn't credit your account until the reversibility period had passed + 3 confirms.  What would someone else loose in that situation?  You would have been the person to encumber your coins to protect yourself against hacks, so you can't argue that you would be loosing anything you didn't know you were giving up.

Transaction "reversibility" is not useful without some form of arbitration, which forces a human element into the transaction.  Paypal reversibility can be useful (in theory) in the sense that a third party judges whether both parties fulfilled their obligations in a transaction.  If the person receiving the Bitcoins can provide concrete proof to the third party that they also completed their end of the deal, then the judge can mediate disputes, and reverse funds back when this proof is not presented.

The scenario you present has no extra protection.  Every extra bit of protection to the consumer is simply taken from the merchant.  The merchants will not accept a payment which can be reversed.  They have no way to prevent the reversal aside from simply waiting until it is no longer possible.  If they ship an item, and the buyer reverses a payment, then they have no recourse.

At the end of the day, whoever goes first in a transaction must trust the other party.  Your method does not fix this fact.  It simply re-defines who goes first.  At the end of the day, one party still must trust another party to deliver / not reverse a transaction.

I don't see how the bitcoin protocol could possible support your idea. There is no way to make an address have extra properties. You should probably look into mastercoin or counterparty for functionalities like this, or just a 3rd party provider that handles bitcoin payments.

I think what you are looking for already exists. nLockTime (https://en.bitcoin.it/wiki/Protocol_specification#tx)

Yes, that is what I was going to say.  Can we not already do this with bitcoin's existing scripting language?  Perhaps the script could assign the coins to the recipient's address after nLockTime >= 6 and to an address that you control for nLockTime < 6.  

This is a question for someone above my pay grade, however....

This system would primarily guard against hacking.  It is not about resolving disputes.  One example is the address-switch, where I was trying to pay a merchant.  I sent the funds, but the merchant never received it.  I would reverse that.

Another scenario would if your computer got hacked, and wallet emptied.  You had an alert system for your addresses, you noticed coins moved without your authorization, so you reverse it.

No merchant would suffer at all.  Every merchant would wait for your "hold" period to elapse before they consider the funds received.  If you wanted stuff instantly, don't sent money that has a hold on it.

What you want to be able to do is already possible using transaction scripting and a blockchain enforcable digital contract.

https://en.bitcoin.it/wiki/Contracts

Most likely something similar to example #2, but both example #4 and example #7 have elements similar to what you want to do here.  Alternatively, a third party excrow service can be employed without transaction scripting using only multi-sig transactions.

bitcoin wins because it does not charge back.

if you like chargebacks... use paypal

If your computer is hacked I dont think theres anything youre gonna do to reverese it

There's a lot of big wealthy companies that agree with you OP. I just kind of thought we were tryin to be different.

I was looking in the scripting docs for bitcoin but first of all half of the commands are "disabled" and I can't find anything to make reversals possible for a certain time or dept. And honestly, I think it's a bad idea.

You don't need this.

Just use the escrow features already built into the bitcoin protocol.

Require the original sender to sign the transaction for it to be completed and there you go -- reversible transactions.

You're just slowing everything down.  You're saying that instead of transactions clearing instantly, they essentially linger between the parties for however long you set this reversal period.  The marginal benefit to safety this adds compared to the huge decrease in transaction speed is not a worthwhile trade-off.

Furthermore, if users have the option to send both reversible and non-reversible transactions, hackers will just send non-reversible transactions.

I am finding it amusing that half of the posts are saying optional reversibility would hurt bitcoin, and the other, more-informed half, are saying it is already doable through the protocol.

I'll read up more on the scripting possibilities.  I am a little bit skeptical they will be sufficient to address the hacking risk that I am trying lessen though my proposal.  Why are they not used to greater effect already?  In the current incarnation, the scripting solutions seem quite complex at best, leaving them as an option for experts or offered as third-party solutions.  Isn't it better if we can avoid third parties where possible?

Which original sender... do I have recourse if my private keys were compromised?

QuestionAuthority - I want to send you 1 BTC.  I am going to send it to you from an address I control that is setup with a 5 hour hold.  After 5 hours have passed, is this bitcoin less valuable to you than any other bitcoin?

The chargeback period would have a defined, mathematically enforced time limit.  You just have to wait out that time limit.  My proposal doesn't give either the merchant or the customer the upper hand over each other, it just gives them both the upper hand over hackers.  A merchant would have at least two options for removing all chargeback risk. 
1) Make it policy to not accept any transactions which are from reversible addresses or
2) Wait until the possibility of reversal had expired to ship the goods.

Option #2 is what merchants would do.  If you were silly enough to send a payment to Overstock that had a 1 week hold time, you would just have to wait a long while before they shipped your stuff.


Having an option to slow it down, yes, that is the point.  As my proposal states, you would create an address that was encumbered.  You would do this by choice because you wanted to give yourself time to review any and all outputs from that address.  You would do this to protect yourself against hacking.  The drawbacks of slowness would you be yours alone.  If you didn't think it was worth the marginal benefit, you wouldn't set up a encumber address and you wouldn't add any funds to it if you did.  You're right, hackers would steal the unreversible funds first.  It's up to you what kind of security you want to implement.

MoonShadow, Cbeast, and I all mentioned that a variant of what you proposed may be possible using the bitcoin scripting language.

As a community, we have only scratched the surface of the possibilities offered by the existing protocol.  This is why the necessary tools are not yet available.  I believe you can implement what you want if you spend some more time researching (I know you said you briefly looked).  Perhaps developers like Gmaxwell, J Garzik, Peter Todd etc can give you some hints.  

There are opportunities for innovation with more advanced scripting (and still using bitcoin "as is").

Its s good idea.

Take a quick read of this: http://research.microsoft.com/pubs/161829/EverythingWeKnow.pdf

Reversibility is needed if Bitcoin is ever going to see mass adoption.  I know people say "Only stupid people get robbed" but the vast majority of people have been scammed at some point and a reversible transaction layer is going to be needed.

But what if the seller is dishonest? You sent BTC and then didn't receive what was expected.

With reversibility, seller is at risk, with non-reversibility, buyer is at risk.

Its not just dishonest sellers.  People are always having their bank account details phished.  The banking system protects them by making good any money stolen by the phisher.  If the idea is that Bitcoin can replace fiat currency, a similiar reversible system will be needed.

Not having Transaction reversability is what makes Bitcoin and other cryptocurrencies unique compared to credit cards for example. Lets leave it that way.

I'm not understanding any advantage to this.  Why would someone choose to accept coins that could be reversed?  Either sender is paying or they are not.  If you aren't comfortable with paying up front, the you need to get the receiver to extend you credit - they ship and trust that you will pay up on receipt.   If the transaction is escrowed, then human judgement is involved -- the escrow agent needs to make a fair decision in the case of a dispute, that's not a problem you can solve with just math.

Besides, adding such a system is ripe for abuse -- it would give the Nigerian scam new life.

I think this has been discussed enough, and I don't hear new arguments. Reversal of transactions is possible if the receiver wants to, if not, he only risks fraudulent chargebacks. For all other 'distrust' issues, you go for escrow services, which is also reversible.

That is a respectable position to take if you have no interest in widespread adoption of Bitcoin.  Some of us do want to see it widely adopted.

That's how online commerce works now.  Why do you think Bitcoin would not work if it has the same protections as the dollar?

Check out Mastercoin savings addresses (https://github.com/mastercoin-MSC/spec#marking-an-address-as-savings).

So you are saying we need reversability, to avoid hackers and man-in-the-middle attacks? Imo, the abuse of the reversability would be a lot worse. Instead take precautions so you don't get hacked or mitm'd.

If you want your transaction reversed, just ask the other person to send you the coins back!

/thread

A credit card transaction, as opposed to a cash or irreversible transaction, is different in that the payment processor is acting as an escrow agent.  Money in a credit card transaction is reversible until the sender can no longer reverse it.  The payment processor may extend credit to the merchant to spend those funds until that point, but that is an extra service of the escrow agent/payment processor.

There isn't a need to change how bitcoin works to use escrow.

It already is reversible. As long as the counter-party agrees, they can send the money back to you.   

You seem to be misunderstanding how things work now.

If someone, say your granny, has their bank account accessed as a result of phishing, and all the money taken out, the bank will make her good.

She will not lose a penny.

If you want Bitcoin to replace the dollar, you need the same functionality available to the same credulous non-technical people.  

Someone takes the time to craft a phishing email.  They then take the time to access a bank account and take the money. 

That person is not going to mutate into a counter-party that agrees to send them money back.

Which is more than enough.
For any other means of reversing a transaction, please use PayPal.

With all due respect, please reread what I wrote.  For the credit card processing system to work, funds to the merchant are either held in escrow or given to the merchant on credit.


And granny could be mugged for her cash, or her bitcoin's private keys.  Both are terrible crimes.


Such a problem could be solved by companies proving an ubiquitous escrow service, like VISA/Mastercard.

I think people have only read the title to my post, and not the proposal.  :(  Seriously.

This is not about protecting the two parties in a transaction from each other!!.  This would be used to make sure your funds got to the intended destination or if your computer was hacked, you could recover the money, if you acted fast.

Do people understand there would be a time window of your choosing?  It could be as short as one block?  There are good points to make against this idea, but so far hardly anyone has addressed what I wrote.

I'll just restate again for people to lazy to read my OP - an address would be optionally designated by you, ahead of time, as reversible for a given time period.  If you were a merchant, or anyone else receiving funds, you see immediately upon receipt that the funds were provisional and could be rescinded.  You would not treat reversible funds as cleared / confirmed until the hold had expired.

Once the hold expires, they are no longer reversible.

This system would not in any way protect you from an dishonest merchant whom you sent fund to.

OP I only had to read the subject of this post to be able to say that transaction reversability would be a bad thing.

So, we are in agreement that crimes should be prevented and that grannies being non-technical and not strong enough to win fist fights is no excuse to rip them off.  Good :)

No escrow service could work without the ability to reverse transactions.  Otherwise, you'd have people "scamming" themselves whenever they want extra money.  If you believe an escrow service will be needed, then you believe reversibility will be needed.

If this isn't about escrowed transactions, then you can already do this.  You have ownership of funds by being the sole possessor of the private keys.  If you feel that your private keys are compromised, then you transfer the funds from that address to another address/private key before the thief does.  

From the point of view of a legitimate receiver, the sender (the possessor of the private keys of the inputs to the transaction) is in control of the funds until the transaction can no longer be reversed.   How would this be different than just waiting to pay the receiver at the time when the transaction can no longer be reversed?  

Here's the point:  bitcoin itself is a system of irreversible transactions.   To make a reversible transaction, you need funds to be held in escrow or through credit through an escrow agent.  An escrow agent must be accountable for the decision made to reverse a transaction.   You can't do this without an escrow agent.

Without an escrow agent, it just opens up the possibility for more scams -- I sell something on craigslist, you pay me with a reversible, non-escrowed transaction.   As soon as you get home, you reverse the transaction and I am ripped off.   No thanks.

What if you were trying to send funds to Overstock, but an attacker spoofed the payment address?  You had control of your keys, you tried to pay Overstock, but they never got the funds?  What then?  That is an attack that this system could help to neutralize.

I do not support any reversibility other than voluntary return. Any thing like that would surely lead to exploits that make things even worse. Buyer beware is brutal, but fair.

Most of the scamming that I see here is very easy to avoid. People seem to have forgotten how to look out for themselves and think someone else is protecting their financial interest. Welcome to freedom and her bitch of a sister responsibility.

I find this analogous to walking to the store with cash in my pocket.   It is my responsibility to make sure I'm not pickpocketed on the way to the store.   The store, in an effort to keep pickpockets away from their customers, should be providing security to minimize this.

Those not comfortable with walking to the store with cash in pocket might consider using an trusted escrow agent to ease their minds.

I strongly disagree.

I believe that the irreversability is one of the most attractive features of bitcoin.

If you support reversability, perhaps use some other payment source like PayPal or Skrill.

Have you ever thought why some people hate Paypal? Reversibilty's the name of the problem.

Title changed.  Original post the same.

I probably shouldn't have posted in the general forum, where the quality of the discourse has clearly degenerated to a point where it is hardly worth posting.

If the system is optional, couldn't a hacker or thief send the stolen coins as irreversible? Unless you mean the transaction reversibility depth is set before the transaction is made, which can cause problems in itself. Assuming the former, I suppose it could help with man in the middle attacks, if it noticed quickly enough.

Edit: Of course there are other potential issues that could arise from this.

Read the first reply to your OP....


Lame....

Such a waste of time discussing with you because you obviously dont understand.... Too bad some members here didnt value their time as much as i do.

Chao

It is a reasonable question that should be asked. No one should fault you for asking, but it has been asked for years and strong opinions have developed.

Not the way I was proposing.  The first step would be to create a protected, reversible address.  Then you would fund it.  Any funds ever sent from that address would be reversible until the predetermined block limit had passed.  So if the private keys to your protected address were compromised, you would have a time window to undo it.

Only funds on addresses that were setup to be reversible would have any protection.  Regular address would subject to instant spend as is currently the case.

100% agree with this post

just use paypal and leave bitcoin if you like reversible transaction

Explain how this is different than just posting the transaction when the predetermined block limit has passed?

Well you can't know your transaction was received by the intended recipient until you send it and they get it.  If you send some coins, and they are not received at the intended destination, you could potentially take corrective action.  Just waiting to send a transaction would not accomplish this at all.

With a few tweaks, couldn't escrow be made friendly, right inside the client? And wouldn't that be just about the same thing as reversability? Should a date be added where the escrow would be cancelled, and the transaction would automatically go through?

Actually, the whole idea of reversability beyond escrow is stupid. Escrow is almost like reversability as it is. Either you give the other guy his money or you don't. If you can't trust him at a distance, then get face-to-face with him and use cash. And keep your gun with you in case he grabs the product back out of your hands after you pay him. And if he has a bunch of his buddies along with him, come back when you have your buddies with you - all heavily armed, of course.

The point is, escrow companies are all that we need. The next best thing is the thing that LocalBitcoins and Bitcoin-Otc are doing. Rating the users so that we know who to deal with.

In all events, only trade small amounts until you are certain you are dealing with reputable people. Reversability amounts to built-in stealability.

:)

If that is the goal, it would seem that the system that was compromised by a man in the middle attack should burdened with the task of encryption necessary to prevent the attack.  I don't see why the blockchain should be burdened for a lapse of security of the system between sender and receiver.

So potentially a user could have many different addresses holding coins, each with their own specified amount of time (blocks) of reversibility? For example, Alice has 3 different address that currently hold coins. Coins in address A are irreversible, coins in address B are reversible for 10 blocks, coins in address C are reversible for 1000 blocks.

Exactly!

You could give the transaction an nLockTime, sign it, and send it to them. They then confirm receipt. When the nLockTime expires, they broadcast the transaction, and then dispatch your goods. If they don't confirm receipt, you create a new transaction that sends the same funds back to yourself. Then when nLockTime expires, it's too late, and the first transaction will be rejected as a double-spend.

I'm not sure how their confirming receipt is any less able to be faked than their sending you their payment address in the first place, but that's also a problem with your new protocol.

Your other scenario is someone hacking your wallet. One problem here is what do you set your reversible time to? If you set it to a short period, say 5 hours, you may not notice the hack quickly enough. If you set it for a week, the hack might happen when you are on holiday and you'll still miss it. If you set it for longer, then it becomes impractical to spend the coins normally because Overstock won't want to wait weeks for the transaction to become irreversible.

In summary, the benefits of your idea over what we already have seem too minor to be worth bothering with. You can also get forms of reversibility by using escrow agents, and you can get defence against hackers by using insured storage (eg, Elliptic Vault).

Private judges, like from Robert Heinlein's "The Moon is a Harsh Mistress."

----------

 A boy about fourteen spoke up. “Say! Aren’t you Gospodin O’Kelly?”

 “Right.”

 “Why don’t you judge it.”

 Oldest looked relieved. “Will you, Gospodin?”

 I hesitated. Sure, I’ve gone judge at times; who hasn’t? But don’t hanker for responsibility. However, it troubled me to hear young people talk about eliminating a tourist. Bound to cause talk.

 Decided to do it. So I said to tourist, “Will you accept me as your judge?”

 He looked surprised. “I have choice in the matter?”

 I said patiently, “Of course. Can’t expect me to listen if you aren’t willing to accept my judging. But not urging you. Your life, not mine.”

 He looked very surprised but not afraid. His eyes lit up. “My life, did you say?”

 “Apparently. You heard lads say they intend to eliminate you. You may prefer to wait for Judge Brody.”

 He didn’t hesitate. Smiled and said, “I accept you as my judge, sir.”

...

 “Kids are paying seventy dollars Hong Kong for judgment. You should match it. If you can’t, open pouch and prove it and can owe it to me. But that’s your share.” I added, “Cheap, for a capital case. But kids can’t pay much so you get a bargain.”

 “I see. I believe I see.” He matched with seventy Hong Kong.

 “Thank you,” I said. “Now does either side want a jury?” Girl’s eyes lit up. “Sure! Let’s do it right.” Earthworm said, “Under the circumstances perhaps I need one.”

 “Can have it,” I assured. “Want a counsel?”

 “Why, I suppose I need a lawyer, too.”

 “I said ‘counsel,’ not ‘lawyer.’ Aren’t any lawyers here.” Again he seemed delighted. “I suppose counsel, if I elected to have one, would be of the same, uh, informal quality as the rest of these proceedings?”

 “Maybe, maybe not. I’m informal sort of judge, that’s all. Suit yourself.”

...

 I went behind desk, sat down, put on Brody’s plug hat—wondered where he had found it. Probably a castoff from some lodge. “Court’s in session,” I said. “Let’s have names and tell me beef.”

----------

Point is, we don't need any governmental judges to judge in practical situations. We all live life. We all understand what's right and wrong... at least in the more evident cases. We don't need reversability of Bitcoin. We may want private judges, and for a judicial fee. People could build a rep as an impartial, fair, private Bitcoin judge.

:)

That would be a way of accomplishing the main-in-the-middle defense part of what I proposed.  Difference is it is on a per-transaction basis instead of a per-address basis.


Its easier to fake just one thing than two.  The same logic is behind 2 factor authentication. Just because one thing (the payment address) has been compromised doesn't mean everything else has been too.  If the receipt of payment came over a different channel, say a sms or email, that would make the deception harder to pull off.

In no way whatsoever do that have to do with my protocol suggestion, which is about bitcoin, and not for how one might go about verifying the authenticity of communication with another party.


This is a logical trap you are trying to set.  You are in essence saying "options are bad, because how do you choose?".  Right now, everything is instant.  Instant would remain a choice, so if you didn't see any benefit in having any sort of time-lock, just keep all you coins instantly spendable.  Easy.  Other people might not feel so paralyzed by indecision, and realize there could be a worthwhile security benefit to having some of there coins take 12 blocks to confirm instead of the usual 6.  It's a tradeoff that every person could judge for themselves, and given a choice, people would come to different conclusions based on their individual circumstances.


It may be so the benefits are too minor.  I know other companies can and will offer such services on top of the blockchain.  Although having needed functionality as part of the chain can save us all from the counter-party risk and fees of turning to those companies to conduct our business.  I appreciate that you read my proposal.

Well, your idea was suppose to be good, but you got it twisted..

A more than complex question reading through the replies I see some good points so not really going to put anything up

Just more of a note that while we haven't even scratched the surface of the protocol, it is possible to build a system onto the current one that can address these issues, including contracts and timed confirmations

Anyways this is a timeless issue going back to the beginning of bitcoin so sooner or later an idea will emerge to solve it whether people use it or not will depend on if they see utility in it
After all it would be part of a voluntary system 

what happens if someone encodes a child abuse video in one of the comments.  how could we reverse that, without arresting everyone on the bitcoin network??

You can't. You may include a link. So shut down the link.

They've been saying that about spam for decades. Not a real threat.

A very bad thing.

Which makes it more flexible. Wallet software could apply it to every transaction from a given address, if that was desired.

Well, no. 2 factor authentication should mean two different kinds of things, such as a memorised password and a physical dongle; not one thing being an email and the other thing also an email (or web page, or whatever).

If they can fake the web page, they can fake the email addresses on it and send emails that are, or pretend to be, from it. As I said before, the gain in security seems so marginal that it is not worth changing the protocol for. (You may be realising how difficult changing the protocol is. The Bitcoin community is quite conservative.)

Both new and old approaches have the same problem, of waiting for a second contact that isn't likely to be more secure than the first contact.

I'm arguing that there is no good choice. The law of diminishing returns sets in too quickly. The benefit of, say, a 5 hour reversible period is minor - the hack can happen while you are asleep or distracted by work. The cost of having to wait 5 hours before an order is confirmed is quite high. Longer periods increase the inconvenience of waiting significantly, without increasing the security significantly. Plus there is now more complexity for vendors accepting bitcoin, and for users managing their wallet options.

My pleasure. I am still new enough to Bitcoin that I enjoy thinking and writing about it. I think many of the old hands have run out of patience with this (general) topic.

Such a bold statement (even though I agree to a lesser extent, more like not good) without any argument. Care to elaborate?

So, rather than sending a reversible transaction, why not just give a "future-dated" transaction to the merchant? After N blocks the merchant can redeem the transaction by broadcasting it, but it can be "reversed" in the meantime by simply spending the coins out of the address. What gives.

It's usually called private arbitration, and one can join an association for such already.

what about Multisig, Consensus(unanimous) transaction reverseability? the Memorycoin voting system could be used to create such a system. this could be used to reverse thefts, however this would be an immense technological achievement. do it right, bitcoins are an even better asset. Do it wrong, we have a serious problem on our hands. the problem with such a system is the time it would take to reverse the transaction. hacker/thief could have did many things, such as trade the crypto for fiat or purchase items from bitcoin retailers. that's just my .02

the only way this would be effective to stop hackers is if all BTC transactions were switched to this "reversable" type ... not going to happen imho !    ::)