Bitcoin Forum

(previous name: Both the protocol and individual coins should have an expiration date)
Too often has the topic of "what to do with users that won't upgrade and become incompatible with the system" come up in the discussions about BIP16/17, and in many other discussions. To put an end to this, I think we should come up with an official time limit of the protocol and even individual transactions, a time limit which will guarantee their acceptance and compatibility.

I am not sayng that after a certian time a transaction automatically becomes invalid, I am just saying that the bitcoin network will only guarantee that the transaction will be kept valid for a certain time, say a year, or 6 months or something like that.

The reason is that bitcoin is a developing system. We cannot just wait for all the people to upgrade, because that just slows down the progress for everyone. If you are using bitcoin, you SHOULD already be very present in what happens to it, if there are any upgrades, due to the inheretnt instability of a such new product. The price varies, there are serious bugs found in clients, if there will ever be a successfull attack on it, that would be good to know also, etc... You should "keep an eye" on your bitcoin assets anyway. So why not make this requirement official? Not only official, but also set an actual time, so the people will know exactly, when to check on their coins and maybe transfer them to new addresses if needed.

Because this argument, which ultimately says that we shouldn't make any changes to the protocol which would be incompatible to the previous versions, only makes the change discussions harder, as if they were not already hard enough. There will always be people who won't upgrade, but if we have an official expiration date for them, then it is only their fault.

Another thing why that would be good is for example the block chain bloating. There is obviously not a defined solution for it yet, but at some point a solution will come up, and what if that solution will mean somehow forgetting parts of the old block chain? Then if we would have an expiration date, we would know exactly how much time to wait to make sure that everyone is onboard.

Huh. So you would force everyone to move their funds to a new wallet at least once every six months in order to keep it valid? That's gonna work. Not to mention making it easier to track where it all is. I don't think that will fly.

Alright, let me be more practical: this would mean that if we set a 6 month period as safe period, people would start up their client at least every six months and check if there are any alerts, and if there, also check the forums, the wiki and look out if there is something they have to do. It does not necessarily mean that they have to move the funds every 6 months, but they would have to keep up, upgrading if needed (if the protocol has changed), and in extreme cases move the funds to another address. But mostly check for alerts, this moving funds thing is just a glimpse of how we maybe going to solve the bloating of the blockchain problem in the future. Right now there are no reasons for moving funds on the horizon. But that's the point, if a reason would come up, the community would know that they would have to wait for EXACTLY 6 months before something can be safely implemented. (6 months after an alert, that is.)

I could see a value in expiring untouched transactions of "0.00000001" so they don't clutter up our resources (the rationale being the cost to persist them on the network vastly exceeds their value to their owners).  But even that is a big if.

The argument of "coins should be touched to not expire" is tangentially related to the "lost coins will ruin Bitcoin" argument.  They are brought up with regularity, and I believe they have been beaten to death in the forums.  "I don't think that will fly" is the conclusion reached every single time.

Yeah, that wasn't the argument, this was an example for a reason why the argument itself would be useful.

After which time the Bitcoins are... what? Forgotten? Sent to your account?

It's a terrible idea. It'd scare people off. It'd kill a lot of use cases, such as having a Bitcoin account as a backing for physical money.

Yes, it might be convenient for development, but it'd be much more detrimental to functionality as a whole.

It would ruin the safety we'd have gained by using BTC as a store of wealth. Maybe you can't be certain you'll be able to use a computer to transfer coins every 6 months or even every 6 years. You'd still want to be guaranteed you won't lose your BTC assets.

In summary, no they shouldn't.

This proposal is not much different than a few prior proposals for 'demurrage' made by a number of users, myself included.  In the end, even I was convienced that such a thing is not only not possible, it's likely counterproductive.

Learn Bitcoin.

The safety? Are you living the same universe as me? The bitcoin price has varied from 2 to 35 just in the last year. There can be a 51percent attack, chain splits, it is even possible that a better currency comes up in the next year and everyone is going to switch to that. Are seriously saving your big money in bitcoins and leaving them there for years? Then you should seriously reconsider your economical routines.

Similarly, if you won't have access to a computer for a year, you definetely shoulnd't be saving in bitcoins.


Don't know how you can say that, my proposal is very different from that. Once again, the proposal is not to invalidate the coins after 1 year, it is on the contrary, to make sure that it takes certain time to make big changes to the protocol and the network so that everybody will have a chance to adjust.

Well if you read what I've written again, the proposal itself is not about what happens to them. But if we in the future will have to make some changes to the protocol, then many different things can happen to them. I am thinking about a solution for people to know exactly when to start worrying that their coins maybe in danger by some new BIP. As of right now many different "timeouts" for protocol changes due to BIP 16/17 were proposed, some as small as 1 month... And it's really difficult to keep track about all of them...

Learn to communicate.


(I've modified the question title to better reflect the proposal.)

It has in fact varied a lot more than that.

Bitcoin is immature, true. Money is about trust. Bitcoin has had 8 (mainstream awareness) month now to build it up. It'll take much longer. But it has potential for real greatness. Your idea would destroy that potential entirely.

The trust in Bitcoin, which in most parts needs to be built yet has nothing to do with the latest pump and dump scheme of some hobby fraudster on the speculation board and the resulting volatility. It has to do with the fact that your Bitcoins will be there whenever one returns. And a Chinese dissident returning from prison after 20 years should be confident that his Bitcoins are still where he left them, whatever their value at that time. Or are you arguing that we should be worse than Paypal and the banks?

Troll exposed. /ignored

Expire coins is a dead argument.

But why not expire the client? Some software vendors do this, and good practice would be to upgrade before expiry. If you could be sure that in 6 months time none of todays clients would still be running?

Would that help the BIP16/17/18 argument and the processes around it?

Supporting old clients is always going to be work, work that the designers could spend in doing other stuff.

Probably a good idea, but the problem to solve is that there are, and should be, multiple client implementations.

Ah yes. And no guarantee that they will comply with "the standard" bitcoin must work anyway.

Basically, yes. But the idea was to expire the protocol itself, not the actual client. The difference is, the protocol will usually stay the same for much longer time than an individual client version will. But if the protocol will be the same, there will be no reason to "expire" it, because it will be compatible with all the new clients anyway.

Of course, we could just build in the automatic autoupdate feature, but that gives too much power to the people controlling the servers and should it happen, a hacker that has compromised the main server, I suppose that is the main reason it has not be done or going to be done at all.



What is going to destroy that potential entirely is when we in future will be forced to implement some protocol change that may invalidate some old coins, or make some other change, even if the coins will be left. And if we do not define the exact time which we have to wait to implement such things, there will always be people that will take that change as a surprise, and THEN there will be rants and people shitting bricks about protocol changes WITHOUT ANY WARNINGS and such. I am trying to think about these things in advance, that's all. If everyone was told in the beginning that any protocol version is only guaranteed to be good for a certain time, then everybody knows what they are up against from the beginning.

If you could get people to make a huge change like moving to an expiring protocol then the whole point would be moot you could get them to switch to anything.

This comment wins.