Bitcoin is not as advertised

[ribuck]

... appeal to the central authority of sourceforge to fix this ...

If you think sourceforge can somehow function as a central authority rather than just being a software repository, then I know that I don't share your other concerns.

[davout]

Since, in my understanding, the protocol itself does not allow any other vulnerability than "beat me up with boatloads of CPU power" (which in my opinion is a feature, not a vulnerability) such an extra unneeded lock-up seems kindof suspicious.

So I'm still waiting for a sensible explanation; if the protocol is as secure as I think it is, the lock is not needed. If the protocol is not that secure, then some exploit needs to get published and the protocol fixed.

Publishing an open source app with an exploit in source ?
That would be foolish. I don't think Satoshi is stupid. After all, he invented bitcoin.

Sooner or later somebody would find the exploit easily. A lot of hackers & programmers have invested their time in this code (and as people invest a lot of money in bitcoin, they will surely do full code review), so it is highly improbable that somebody wouldn't find the exploit by accident.

The linux kernel is made by lots of smart people, that didn't make it free from any vulnerabilities.

[tentative]

... appeal to the central authority of sourceforge to fix this ...

If you think sourceforge can somehow function as a central authority rather than just being a software repository, then I know that I don't share your other concerns.

I was speaking figuratively.

[ShadowOfHarbringer]

The linux kernel is made by lots of smart people, that didn't make it free from any vulnerabilities.

Of course, but these are accidental vulnerabilities.
I meant putting vulnerabilities on purpose. Vulnerabilities like this are usually easily detectable.

[Anonymous]

I dont see how this prevents anyone from creating a better implementation. Isnt that what open source is about?

[tentative]

I think so too, but as of now, nobody has come up with a valid and sensible answer about why parts of the blockchain are locked by the standard client.

The purpose is to prevent an attacker from replacing the entire chain, either due to "boatloads of CPU power" or an unknown bug. See:

The security safeguard makes it so even if someone does have more than 50% of the network's CPU power, they can't try to go back and redo the block chain before yesterday.  (if you have this update)

I'll probably put a checkpoint in each version from now on.  Once the software has settled what the widely accepted block chain is, there's no point in leaving open the unwanted non-zero possibility of revision months later.

But now let's say that during the period of separation satoshi decides on another lock-in point.

If the checkpoint is 1000+ blocks older than the current one, the chance of this happening is almost zero. No one could be stuck in a shorter chain for 1000 blocks without realizing it.

Let's say that the person or community controlling the official release are ever corrupted or make a mistake.
Let's say I have a legitimate longer chain than the one they plan to lock-in.

What do I do?
Who do I appeal to?
Do I report to the police? The blogosphere?
Who will take the effort to verify my claims?
What will be the consequences if I'm proven right?

[kiba]

I think so too, but as of now, nobody has come up with a valid and sensible answer about why parts of the blockchain are locked by the standard client.

The purpose is to prevent an attacker from replacing the entire chain, either due to "boatloads of CPU power" or an unknown bug. See:

The security safeguard makes it so even if someone does have more than 50% of the network's CPU power, they can't try to go back and redo the block chain before yesterday.  (if you have this update)

I'll probably put a checkpoint in each version from now on.  Once the software has settled what the widely accepted block chain is, there's no point in leaving open the unwanted non-zero possibility of revision months later.

But now let's say that during the period of separation satoshi decides on another lock-in point.

If the checkpoint is 1000+ blocks older than the current one, the chance of this happening is almost zero. No one could be stuck in a shorter chain for 1000 blocks without realizing it.

Let's say that the person or community controlling the official release are ever corrupted or make a mistake.
Let's say I have a legitimate longer chain than the one they plan to lock-in.

What do I do?
Who do I appeal to?
Do I report to the police? The blogosphere?
Who will take the effort to verify my claims?
What will be the consequences if I'm proven right?

Just release the god damn bug fix instead of sitting here?

[Anonymous]

I think so too, but as of now, nobody has come up with a valid and sensible answer about why parts of the blockchain are locked by the standard client.

The purpose is to prevent an attacker from replacing the entire chain, either due to "boatloads of CPU power" or an unknown bug. See:

The security safeguard makes it so even if someone does have more than 50% of the network's CPU power, they can't try to go back and redo the block chain before yesterday.  (if you have this update)

I'll probably put a checkpoint in each version from now on.  Once the software has settled what the widely accepted block chain is, there's no point in leaving open the unwanted non-zero possibility of revision months later.

But now let's say that during the period of separation satoshi decides on another lock-in point.

If the checkpoint is 1000+ blocks older than the current one, the chance of this happening is almost zero. No one could be stuck in a shorter chain for 1000 blocks without realizing it.

Let's say that the person or community controlling the official release are ever corrupted or make a mistake.
Let's say I have a legitimate longer chain than the one they plan to lock-in.

What do I do?
Who do I appeal to?
Do I report to the police? The blogosphere?
Who will take the effort to verify my claims?
What will be the consequences if I'm proven right?

Just release the god damn bug fix instead of sitting here?

lol there is no central control which freaks some people out. Welcome to the voluntary society.

[tentative]

lol there is no central control which freaks some people out. Welcome to the voluntary society.

I was probably a member of the open source community before you were born.
I'm not freaking out.
These are legitimate questions when you're dealing with a project controlling the equivalent of over .5M Euro and aspiring for billions.
A handful of active developers can be corrupted.
These dodging answers are not encouraging me to think that this hasn't already happened.

I was starting this investigation to decide whether to invest big money in bitcoin.
Fat chance.

[kiba]

lol there is no central control which freaks some people out. Welcome to the voluntary society.

I was probably a member of the open source community before you were born.
I'm not freaking out.
These are legitimate questions when you're dealing with a project controlling the equivalent of over .5M Euro and aspiring for billions.
A handful of active developers can be corrupted.
These dodging answers are not encouraging me to think that this hasn't already happened.

I was starting this investigation to decide whether to invest big money in bitcoin.
Fat chance.

If there are heavy corruption, you can make lot of money inventing a competing currency. Right now you're just spreading FUD.

[ribuck]

Let's say I have a legitimate longer chain than the one they plan to lock-in...

Who do I appeal to?

You could appeal to the developers who plan to lock in the other chain. If it's due to a bug or other mistake, they will naturally fix the problem. However, if it's due to evil intent, see your next question.

Do I report to the police? The blogosphere?

There's not (yet) a law relating to the lock-in of chains, so I doubt the police will be interested (or even understanding).

You can report the problem here, and you could report it to the blogosphere if you like.

Who will take the effort to verify my claims?

Anyone who shares your interest in a valid block chain will be motivated to make the effort, and those who are technically able to do so will be happy to look into your claims provided they are expressed in such a way that people are motivated to take them seriously.

It's in your interests to explain the problem clearly, and it's in other people's interests to take your report seriously (because their bitcoin balance depends on a valid block chain too).

What will be the consequences if I'm proven right?

Someone will release a version of the client software that works properly, which you and others will use. It's of no consequence to you if there are still some people who choose to use the "corrupt" version of Bitcoin, because you are free to use the version with the correct block chain.

I was starting this investigation to decide whether to invest big money in bitcoin. Fat chance.

No problem. We will welcome you back when you are ready.

I was probably a member of the open source community before you were born.

Then you'll understand how it works, and you'll understand why you don't report bugs to the police, and you'll understand that sourceforge is a tool and not a central authority.

[Timo Y]

I was starting this investigation to decide whether to invest big money in bitcoin.
Fat chance.

Good. More BTC for me then.  

On a more serious note, I wouldn't advise anyone to invest "big money" in bitcoin, even the modified version you propose.

*The security of bitcoin hasn't been thouroughly tested
*there hasn't been any peer review by cryptography/security experts
*critical mass hasn't been reached
*competition from other p2p cryptocurrencies
*the economy is still tiny (liquidation value of all BTC in existence is probably closer to 50,000 EUR than 500,000 EUR).
*danger of massive government crackdown
...

This project is in a very early stage and there are still many big hurdles to overcome.

For the time being, investing in Bitcoins should be seen as high risk investment or nothing more than a fun hobby.

[Anonymous]

lol there is no central control which freaks some people out. Welcome to the voluntary society.

I was probably a member of the open source community before you were born.
I'm not freaking out.
These are legitimate questions when you're dealing with a project controlling the equivalent of over .5M Euro and aspiring for billions.
A handful of active developers can be corrupted.
These dodging answers are not encouraging me to think that this hasn't already happened.

I was starting this investigation to decide whether to invest big money in bitcoin.
Fat chance.

Im not dodging anything. Im  not a developer so I told you where you can talk to the devs on irc. They can more easily answer your questions.

[ShadowOfHarbringer]

I was probably a member of the open source community before you were born.
I'm not freaking out.
These are legitimate questions when you're dealing with a project controlling the equivalent of over .5M Euro and aspiring for billions.
A handful of active developers can be corrupted.
These dodging answers are not encouraging me to think that this hasn't already happened.

I was starting this investigation to decide whether to invest big money in bitcoin.
Fat chance.

1. Because you are not asking correct questions, so You will never receive the answers You are seeking. Learn to articulate your wishes without spreading unnecessary FUD.

2. Most of us here are not BTC developers, just random geeks. If You have a serious question, then either:
a) Go ask the developers on IRC OR
b) Release a patch OR
c) Release a fork

3. You haven't even properly explained your stance in technical details, or proposed a patch. You expect serious answers without being serious Yourself.

[Cdecker]

I think the main problem is that currently we have a single client that can be used. This puts a lot of trust in the developers of this client. So what I think tentative is alluding to is the possibility that the developers may become greedy and release a modified version of the client that plays unfair and gives them a certain advantage. The problem with proving this is that users are not forced to update to the latest version if they do not trust the developers, in fact (except for bug fixes) people could run their current client endlessly, since the protocol itself seems to have solid foundations.

As soon as we have multiple implementations the trust that we have to put into the developers of any of those clients is reduced, but sincerely I don't see satoshi turn evil anytime soon

[grondilu]

As soon as we have multiple implementations the trust that we have to put into the developers of any of those clients is reduced,...

Any progress in that direction ?  I red somewhere that some people wanted to work on a Python implementation of the protocol.

[Gavin Andresen]

tentative: I don't get it.

You seem to be saying that somebody might be secretly working on a longer block chain, and all their hard work will be ruined because they won't be able to replace the block chain everybody else is using non-secretly because the block chain everybody else is using might get locked in.   Ummm... yeah!  Don't work on longer block chains in secret.

Either that, or you're saying Satoshi might accidently lock in a shorter block chain, and most people either not noticing or not caring.  Umm... no, I don't see that happening.

The block chain lock-in check is only done when new blocks are accepted.  Here is what would happen if Satoshi tried to commit a block lock-in that most of the network thought was shorter:

1. Imagine everybody downloads the new client with the bad lock-in.
2. Everybody who had the longer chain before ignores the lock-in, and continues to push the longer chain.
  (unless the longer chain contains a bad transaction-- the chain is checked for bad transactions on startup, see  CBlock::CheckBlock)
3. Newbies who are downloading the chain for the first time will hit the lock-in code, and will be running with a shorter chain.

There will be chaos as newbies generate blocks on the shorter chain, which only other newbies will accept.  "oldies" will also continue to generate on the longer chain.  Transactions will get added to both chains... and the "oldies" will beat Satoshi into submission.  Unless there is a legitimate bug (like the overflow bug that inspired the block chain lock-in code in the first place).

If I am misunderstanding your concerns, please speak up.  The number one development priority for bitcoin is security.  If you have found a problem, please email or private-message Satoshi, or post here (besides possible network denial-of-service attacks-- only email about those if you have a brilliant idea for how to prevent them...).

[davout]

The linux kernel is made by lots of smart people, that didn't make it free from any vulnerabilities.

Of course, but these are accidental vulnerabilities.
I meant putting vulnerabilities on purpose. Vulnerabilities like this are usually easily detectable.

Yeah, they're called backdoors, an exploit is something completely different.
An exploit is a documented and reproductible way to use a particular vulnerability in order to get to a given result (privilege escalation, DOS etc.)

Smartly engineered backdoors can be very difficult to spot.

[davout]

I think so too, but as of now, nobody has come up with a valid and sensible answer about why parts of the blockchain are locked by the standard client.

The purpose is to prevent an attacker from replacing the entire chain, either due to "boatloads of CPU power" or an unknown bug. See:

The security safeguard makes it so even if someone does have more than 50% of the network's CPU power, they can't try to go back and redo the block chain before yesterday.  (if you have this update)

I'll probably put a checkpoint in each version from now on.  Once the software has settled what the widely accepted block chain is, there's no point in leaving open the unwanted non-zero possibility of revision months later.

But now let's say that during the period of separation satoshi decides on another lock-in point.

Bugfix = remove block chain lock, not very likely to happen since satoshi added it on purpose
If the checkpoint is 1000+ blocks older than the current one, the chance of this happening is almost zero. No one could be stuck in a shorter chain for 1000 blocks without realizing it.

Let's say that the person or community controlling the official release are ever corrupted or make a mistake.
Let's say I have a legitimate longer chain than the one they plan to lock-in.

What do I do?
Who do I appeal to?
Do I report to the police? The blogosphere?
Who will take the effort to verify my claims?
What will be the consequences if I'm proven right?

Just release the god damn bug fix instead of sitting here?

EDIT : Fixing = reverting some of satoshi's code, for some reason I don't see that happening
Also, no one actually answered as to why there was a block chain lockdown hardcoded, it doesn't solve anything, not even CPU overpowering attack on the network.

[Cdecker]

As soon as we have multiple implementations the trust that we have to put into the developers of any of those clients is reduced,...

Any progress in that direction ?  I red somewhere that some people wanted to work on a Python implementation of the protocol.

Still working on it but 2 jobs and my studies are taking their toll on free time to spend on Bitcoin related projects. People offering to help understand the protocol are always welcome: http://code.google.com/p/pybitcoin/wiki/BitcoinProtocol