Bitcoin.
What Jero means is that average users will be fine, it is not like NLG will have just vanished out of anyone's wallet while they were not using it, only people receiving NLG in exchange for goods (services like exchanges etc.)

As a regular user you can just look in your transaction list, transactions will not get a check mark next to them until they are safely behind a checkpoint.

From an API perspective we have modified the 'listtransactions' RPC call to have a new field "secured_by_checkpoint" which will contain "yes" if the transaction is check pointed and "no" if it is not, we have also added a configuration option which can be set if you want 'listtransactions' to only ever return check pointed transactions.
It is up to all services to make use of these if they want to be 100% safe in terms of double spends, however the checkpointing does help quite a bit even if they don't as it makes the attacks a lot harder to execute smoothly anyway.

We didn't patch any bugs specifically, as the double spending was not as the result of a 'bug' but rather is just a design limit of how crypto coins work - if you have 50% you can execute double spends.
What we have done is we have added an automated checkpoint system as an extra, this is intended to protect the network against double spends so long as you only deal with transactions that have been checkpointed you will be safe from a double spend.

In the long/medium term we have some better solutions we are considering which will then replace this solution.

Not specifically related to a timewarp attack at all.

They are tagged, however I will make a point of including it in the commit message as well in future.

After testing I did a final code review, the check-pointing code we used as a base for ours had while loops without control braces which is not something that is usually recommended and causes warnings with many compilers, so I re-factored this to put control braces.Due to some weird white space and  tiredness/stress I accidentally got the one set of braces wrong and slightly changed how the code worked. This has caused the checkpoint to reject valid blocks if activated in some cases.

I should have known better than to do any refactoring even if it seemed really trivial as main testing had already been done, unfortunately when resources are stretched thin and stress levels are high sometimes these things happen.

We have been working hard on improving our testing - one of the lesser publicised changes about 1.5.4 is that we now have a permanent live public testnet, and we want to work on getting more community members involved in helping us test in future, so hopefully we can grow the team in a way that helps prevent these things in future.

Anything is possible but it is not likely, I've now triple checked that the code is the same as what we had when testing and am doing some retesting to be sure, the new builds are on the way and will work.


Apologies to everyone for the extra hassle here.

We are in #gulden on freenode - however it is rather small, the slack community is much larger.

Thanks for this, will clean those up for next release, please feel free to use our bug tracker https://github.com/Gulden/gulden-official/issues

Just a note, the check pointing will not be activated until *after* a majority of users and miners have upgraded (to prevent fork issues) so please remain extremely cautious for now in terms of transactions until check pointing kicks in.
The clients will show circles instead of check marks next to transactions until the check pointing is active, only transactions with a check mark next to them can be considered as safe from double spending.

It is the way you word things that makes all the difference, if you actually want people to take the time to give a serious response to you then I strongly suggest you go back and look at how you have worded your last message and do the complete opposite in future.
As for our medium and long term solutions, we will release more on that when we are ready, there is no point discussing it before then.

New wallets are in the process of being built, it takes a few hours so likely tomorrow morning.

While that may very well be true, without evidence I don't think anyone should be pointing fingers anywhere, if anyone has any evidence please feel free to come forward.


Yes, we don't consider it a good long term solution for Gulden, I'm not going to go into any more specifics than that, you can probably find some details earlier in this thread or on our official forums if you are interested.

I don't do that sort of thing, if I did I would already be retired on an island somewhere plenty of coins out there with easy to target giant vulnerabilities in them.
We are here to build things not tear them down.

No.

No, checkpoints are to protect vendors and users from attacks not rollback the chain.

It seems incredibly likely that unless we put a fix in place they will do it again and again.

You cannot stop a double spend just by keeping a close eye on it.

We have been more than clear that this is just an interim solution. In the medium and long term we plan to put better systems in place.

Oh right you are just here to troll without anything positive to contribute to the world, I won't waste any more valuable time explaining things to you then.

To be more specific you are only at risk when receiving NLG in exchange for something.
e.g. If someone sends you 1000000 NLG and you send them 10 BTC, that 1000000 NLG transaction might later 'disappear' leaving you with no NLG or BTC.

So in short exercise extreme caution in such situations for now, although that is anyway a good idea always.

Not 51% attacks entirely, just double spending.
There are other attacks that can be executed via 51% e.g. denial of service and this won't address those (they aren't the immediate concern as they are less likely - no financial gain)

This is just an interim solution so that we can move on in the meantime, in the medium term we will be putting out better solutions.

I'm busy working on a fix but it will take a while still.

Market cap alone is a very sketchy indicator of anything, especially when it is based on as little as $100 (or less) volume.

In my opinion, low hype  and no gimmicks. I suppose some may call these tactics (hype and gimmicks) 'marketing' however as many other coins have shown it is not sustainable, in the end massive hype leads to a massive crash, easy up easy down...
Gulden is focused on long term sustainable growth and not short term gains and I for one feel this is much more important.

Exciting times.

Reminder to all to have your say on the wallets here https://community.gulden.com/t/features-you-would-like-to-see-in-the-wallet-s/1323