Bitcoin Forum

I am starting this new post from another thread because I think it needs further discussion.

Right now gold can be mined and used as a currency.  You can also use gold to make jewelry, build circuit boards, etc., because it has special properties.  Therefore, gold has more than one purpose which increases its value.  As of now most people believe that bitcoin can only be used as a currency.  If people start using bitcoins to timestamp their work, then every bitcoin actually has more intrinsic value because it has more than one purpose!  A bitcoin is actually not only useful as a currency but it has the ability to timestamp.  If someone could use this special bitcoin property similarly to how scientists used the conductive properties of gold, then bitcoins could takeoff in a different tangent which could further increase its value.  Is there a breakthough application waiting to be discovered using the timestamp property out there???

Please brainstorm how to use bitcoins in new ways and post your ideas here.  

I saw this analogy on the other thread and I thought it was a good short justification for not restricting Bitcoin use.

ByteCoin

One of the major disadvantages of bitcoin at this point in time is that it serves no purpose other than a currency.  In essense, it is like fiat currency; it is only worth what people think it is worth.  100% of the price increase of Bitcoin is based on money put in by investors.  If Bitcoin had another purpose the price of Bitcoin would be based not only on money put in by investors but the additional demand caused by that purpose.

What alternative uses could exist that wouldn't detract from the primary function?

I think that the answer to that question depends very much on what exactly what it is, the primary function of which we are discussing. Bitcoin has recently proved to be a moving target. It used to have an effective scripting language but now it doesn't. There's little point discussing alternative uses if these alternative uses can be easily denied.

Gold is superior to Bitcoin in this regard. Once you have your gold, nobody can decide to change its maleability so you can't make it into jewelry or it's reactivity so that it tarnishes.

Is Bitcoin what the current software permits or is it what the fundamental technology could allow?

ByteCoin

The problem with using bitcoin to timestamp is the possibly of bloating the blockchain, making fees goes up...

Cryptographic timestamping service is also something that is widely available commercially and not exactly a problem the world needs solved, as compared to the shortcomings of centrally administered currencies.

Oh boy, it seems people will never get over this intrinsic value fallacy (http://www.thefreemanonline.org/featured/the-fallacy-of-quotintrinsic-valuequot/).

It's actually funny... one of the advantages capitalism brings is specialization. Not only skill specialization, but resources as a whole. Always trying to use the best cost/effective material for a certain purpose.
So, why do you people want money to be useful for something else? Why, particularly for money, people are against specialization in the use of resources?

Money doesn't need to have other uses. Actually, I dare to say it would better not have other uses.

And, by the way, why would one want to use money to timestamp stuff? Can't there be a cheaper (= most efficient) way to do it?

Quoting from the link you provided...


So what I am looking for are special properties of bitcoin that we (men) can use to add value to it, that can augment to it's historical value.

I understood what you want. It's more the reason that I don't get.
If it's more from an "investor" point of view (raising the value of bitcoins for profit), then, ok, it makes sense you wanting that.
But if it is because you think this is important for the currency itself, otherwise it wouldn't be a good currency etc, then you're wrong.

Now, about finding other uses... I don't think there can be another use for bitcoins which wouldn't have more efficient alternatives. Like your suggestion, timestamping... I bet there are better ways to do it then with bitcoins. So, I wouldn't waste much effort in this idea if I were you...

The obvious answer is bitdns which has been discussed at length. Either it will be added to bitcoin and the current block chain or it wont be in which case domaincoins have the potential to be a better currency than bitcoin. One option would be to contact all the other timestamping services and get them to accept bitcoin.

That should be easy considering the similarity.


For instance someone might want to establish prior art by sending a document to a timestamp service. A fee could be paid in bitcoins for such a thing. Establishing prior art is a valuable service.

I absolutely agree than intrinsic value is a fallacy, but I still see possible value in putting other things in there. I'm not sure what, at least for now there is nothing I'd like to put in there.

I can see how people are annoyed though, when it becomes 'cool' to encode things in the chain fees will start pretty much immediately. Then we'll see what the best use of the chain is. It won't be spam, it might be money only, or money and other stuff.

It's quite similar to currencies but I'd like to mention possible use of bitcoin for equities market.

A company would modify the bitcoin software to create its own cryptocurrency.  The total amount would be much lower, so that the company could make it possible to own the whole initial stock (running the software alone during some time before realease, for instance).

Bitcoin timestamps are worthless.  If you examine the timestamps in the blocks, you'll notice that many blocks are timestamped to be older than the block before it.  This is impossible, of course.  The best you have got is a sequence property.  Blocks are generated at random times centered around 10 minutes (actually less, which is why the  difficulty keeps increasing), which is another property, but I don't think Bitcoin blocks would be very useful as a source for random numbers either.  Bitcoins are however very useful as a secure currency or commodity.

The block number IS the timestamps !

No.  The block number is a sequence number.  You can not derive time from the block number with any useful accuracy.

The network tries to keep the block timestamp accurate within a few hours. This is useful for some things.

Bitcoin uses it for difficulty adjustment, so it has to be at least generally accurate.

As I wrote earlier: You can find many examples of blocks with timestamps older than the block before, or even several blocks before.  I can't imagine why anyone would want to use such an unreliable timestamp when accurate timestamps to the microsecond are easy and free.

When all you have is a hammer, everything looks like a nail.  "I can probably make the window fit in the frame using my hammer."  Maybe, but it is a horrible choice of tool for the job.

So? They're both accurate within a few hours, as I said.

In these cases, the producer of the second block believes that the first block has incorrect time. What do you expect him to do, other than use correct time?

The producer of bitcoin blocks can do whatever he wants, and that is one reason why bitcoin blocks are useless for the purpose of timestamping anything.  The original claim was:
Bitcoins are worthless as a source for timestamps.  The block creator can put whatever he or she wants in there.  Almost.  Look at the timestamps in the current block chain.  Try to imagine anything relying on timestamps where timestamps invented by the block creator is a useful property, when accurate timestamps with microsecond resolution are free.

Another claim is:
But it isn't.  The block number is a sequence number, and the timestamps aren't even in the correct sequence.  They don't need to be for their current purpose.

If you are looking for gold, you should try other properties of Bitcoins.  Your wallet contains some cryptographic keypairs which may be useful in connection with bitcoins for messaging or verification purposes outside the blockchain.

If BitDNS or <other programmers pet project X> becomes conjoined to Bitcoin, I am instantly selling all my BTC and leaving.

The timestamp must be after the median time of the last 11 blocks and before 2 hours in the future (using adjusted node time). The timestamp will be accurate within a few hours unless a powerful attacker is trying to make it inaccurate. I believe moving the timestamp forward or back by more than 2 hours would require more than 50% of the network.

This property is valuable in certain circumstances.

You could have saved the trouble of writing all this by quoting one more word from me: Almost.

Name one.  It's good enough for their use in the Bitcoin blockchain.  For other purposes the timestamps are still worthless.  Accurate timestamps are free.

I would too.  So the exchange rate would crash.

To what end?  A digital stock cert is easier, and doesn't require a timestamp.  Anonymous ownership of stock is risky for the investors, and illegal in most nations anyway.  Anonymous "bearer bonds" are also banned in most nations, due to a history of their use in money laundering and finanacing of wars. 

The standard use of a timestamp server is to prove that you created something before a certain date. Rarely in these cases do you need anywhere near the two-hour accuracy that Bitcoin provides.

For example, say that I have figured out how to break AES encryption. I put my method in a text file and hash it. I put the hash in a block. Then, if someone else finds the same method independently, I can prove that I was the first one to find it by showing them the hash in the block. Unless someone found my method less than a day after I did, observers can be very sure that mine came first because the block timestamp is reliable enough for that.

It would be enough, and much easier to mail it to someone.  Use a gmail address or something, and you will have your timestamps accurate to the second, at least, on many external locations.  This method is free, and not an annoyance to thousands of Bitcoin users all over the world, who are paying for their internet connections.

A decentralized equity market would hve no brokerage fees.  This is good enough a reason do make it real, to me.

I don't care if it's illegal or if it can be used for money laundering or whatever.  Laws are decided by people.  I'm part of 'people' so I give my opinion and I say I wish anonymous ownership of shares was legal.

But corporations are creations of the state, and by proxy, so are stocks and bonds that these corporations release.  How, for example, can you ensure that the corporation that you invest in isn't going to deny that you are even an investor without the threat of the force of the courts?  Sure, you could sue in a common law court, but how would you get the losing party to pay the judgement if they don't even recognize the authority of the court? Bitcoin works because there is no counterparty risk that is always central to any particular Bitcoin transaction.  But stocks and bonds are just promises, and are primarily counterparty risk.

Corporations are NOT creations of the state.  They are private associations of people.

I can't ensure that the corporation won't fool me.  This is what trust, reputation, and responsability is about in a free market.  If I get screwed, I get screwed.  Period.  State should have nothing to do with that.

Yes, stocks and bonds are counterparty risk.  So what ?  It's up to me to price this risk during my bidding.

Not the way that they exist and operate in our modern world, and certainly not in how they are funded.


Fair enough.  I think that it's going to be a tough sell for either side of the equation.

It's not that difficult.  Dark pools exist and are actualy quite successful.

I didn't think that you were talking about a dark pool.  A dark pool is just a hidden market, there is no reason to use a blockchain to do this.

There is.  Again :  zero brokerage costs.  Better confidence in the system.  And so on.

This seems like an overreaction. If some junk transactions come in that's okay, but if the transactions mean something to some people then it's awful?

That is what we're talking about right? A system whereby "bogus" transactions are interpreted in an agreed upon (by some people) to mean a certain thing. Is that right? I don't see a big problem here, maybe I'm not getting it though.

If I wanted to timestamp a hash in a publicly obvious way to prove later that I had known an idea at a certain date... I don't need Bitcoin.

I would merely go put the hash on my user page over at Wikipedia, and then perhaps remove it so it is visible only in the history.  The edit history is visible to the world, probably will never get erased, will get mirrored a ton, everyone understands what Wikipedia is, and there would never be any need to start explaining to the baffled ladies and gentlemen of any jury what a block chain is and how it proves anything, never mind a hash.

Except that it means you trust wikipedia as a robust website that won't be destroyed or altered in a foreseable future.  Rememeber also that Wikipedia is not designed for that, so wikipedia bureaucrats might very well decide to remove your modifications from the history, just in order to save some storage space.

The advantage of bitcoin is that you don't have to trust anyone in particular.

I think this illustrates why we don't need to worry about DNS data filling up the chain. Since there are cheaper ways to do it, people will not throw away money paying fees. Some people thinking bitcoin is an efficient way to do it might try for a while, but that's no worse than spam imo. Maybe better since it doesn't have that malicious feel.

Oh yeah, maybe it does need something like bitcoin. I'm still unsure.

Wikipedia makes its entire database available for download, plenty of mirrors are around, no fear that such a thing would disappear.

A thirty-two byte hash on one's own user page doesn't stand a remote chance of annoying bureaucrats.   If I put "F all WP's bureaucrats" in 90-point font on a popular page, that wouldn't even meet the threshold of them wanting to delete it from the permanent history, so why would they do this to recover disk space worth 0.0000000001 BTC just to hide some numbers?

Many people already put hashes on their own page for the purpose of being able to prove their identity if their account gets hacked.  Knowledge of plaintext = proof of account ownership (google "Wikipedia committed identity").  It's something they actually tend to encourage.  The plaintext doesn't have to be anything in particular, it just has to be something you can prove you know (assuming you ever get your account stolen and need to prove you're the rightful owner).  If the plaintext was "I cracked AES and here's how I did it ..." and called the hash my committed identity, it would be timestamped and condoned.

Still, a would prefer a trust-free system.  Personnaly I don't think Wikipedia will last long.  Too much centralised.

The fact that they depend on donations is a proof of that.  Had it been designed in a purely decentralised manner, they would not need that much money.

Do you mean making their entire codebase and content available free (GPL/GFDL/etc.) in a huge tarball on a regular basis doesn't achieve an acceptable degree of redundancy?  Their dependence on donations is only to the extent they overtly refuse advertising for philosophical reasons of neutrality.  It's not as though they don't have the traffic base to sustain themselves if they ever went with ads.  If Wikipedia died as you suggest, and If I have a needed to make use of my timestamp from long ago, I am sure its appearance on Wikipedia's mirrors would suffice (WP has so many mirrors that the mere LIST of them is split into alphabetical sections...#ABC - DEF - GHI - JKL - MNO - PQR - STU - VWXYZ)

Yeah, but then you'll have to trust those mirrors not to remove any data in the edition history.

Personnaly I won't believe in Wikipedia's full persistence until it is fully P2P.  Just mirroring won't accomplish that, imo.

What about private companies where the  shareholder is one individual? I dont see anything wrong with that necessarily.

That would have to be one heck of a conspiracy...

I will also have to trust that my neighbor won't burn my house down with me in it... or that my dog won't stab me through the heart with a rough edge of a doggy bone in my sleep... or that I won't slip on a bar of soap and crack my head open and die tomorrow... if any of those happen, my timestamp will be worthless all the same (because I won't have a need for it...)

I'm not talking about a full destruction of the whole Wikipedia database.

I'm talking about a cleaning of its history by most mirrors.

If a someone on Wikipedia uses oversight to remove your revision, I doubt any mirrors will go out of their way to keep your data alive.

Perhaps if the cost of disk space starts going up (it currently isn't).  But if most mirrors really decide to go to such lengths, I will just have to get my timestamp from one of the ones that didn't. :)


If someone on Wikipedia uses oversight to remove my own committed identity hash from my own user page, I will pinch myself to make sure I'm awake.  This too is about as unlikely as me slipping on soap tomorrow and dying...

Also, if timestamping was to gain any importance in the future (for instance if it was used to validate official documents and so on...), then some people might be willing to counterfait them.  So there would be some fake Wikipedia mirrors that would make some fake timestamps.  It would then be difficult to prove that your timestamps are more genuine than others.

Finaly, your trust in Wikipedia gives Wikipedia's bureaucrats a power they don't deserve imo.  They could, if they want, forge fake timestamps and then claim ownership of some intellectual work.

Bitcoin's timestamping would be much more robust against counterfaiting.

Truth is that if wikipedia was really reliable as a timestamping server, then we would just not need bitcoin at all (!).   Timestamping is pretty much the very core orignal service provided by bitcoin.  I doubt there exist anything in the cyberspace that can do it better.

Wikipedia's bureaucrats would never have a clue that's what I was doing, so they'd have no way to abuse that misplaced trust.

I don't mean to suggest that Wikipedia should become the world's de facto timestamping service.  They are just there and practical if I needed something timestamped.  What I understood is that people are arguing for making Bitcoin a system that arbitrarily timestamps things for people, anything they want, not just its own transactions.  Wikipedia obviously won't serve as a backend for timestamping Bitcoin's load, I've never suggested this.

For comparison's sake, I also own a Certified Document Services signing key for Adobe PDF.  I had to pay for this.  It comes in the form of a FIPS-compliant USB hardware cryptographic module that I have to unlock with a password each time I use it.  If I digitally sign a PDF, Adobe Reader cryptographically recognizes the signature, which also incorporates a cryptographically based time stamp.  This is what I will use (along with perhaps two or three other methods) if I come up with any invention that I'm scared conspiracies all around me will try to steal.  For all else mundane, Wikipedia will suffice, as will:

- paying for a newspaper ad with the hash (the newspaper may charge a lot or relegate it to the WTF section of the newspaper, but...)

- posting my hash on facebook, twitter, etc.

- printing it on a postcard and mailing it to a few dozen people

- writing it on something that will be filed as public record

etc...

At the end of the day, the world already has plenty of satisfactory timestamping solutions without needing to pollute Bitcoin with another.

Again :  timestamping is pretty much the core of bitcoin service.  The distributed time server is the most original idea of Satoshi's design.

I just don't think any other solution is better.

Agreed

Using several trusted parties does improve the global trust, but it doesn't change the model.

It's just as if you were advocating in favor of bankin gystem against bitcoin, saying that basically if you don't trust bank A, then you can withdraw your funds and go to bank B or C or D and so on...

The model is alsways the same :  at the end of the day, you have to trust SOMEONE to take care of your data.

With bitcoin, the model is completely different.

In principle, I would consider it a fallacy to try and mimic gold. Gold has many flaws but in the non-digital era it was the best we could find as a currency for lack of alternatives. Bitcoin can be something fundamentally different to gold, and it should be if that makes it a superior currency.
 
If we start using Bitcoin for generalised timestamping and whatnot, this might increase their value, but it will also indroduce additional costs and vulnerabilities into the network.

KISS.

Satoshi himself pointed out that using bitcoin as a timestamping service is something we can not prevent.  See here : http://bitcointalk.org/index.php?topic=2162.msg28533#msg28533.  Therefore, there is no point trying to prevent it from happening.

And it does not add any complexity to the system.  At all.

Are you all mad?

What you call timestamps are so inaccurate and easy to skew that the best you could do is a datestamp.  If you want to make a reliable system for timestamping, you should at least make the clients to agree on the time within a second or less.  Satoshi could have done that if he wanted to make the system useful for timestamping, but he didn't.  There are many systems out there which are made for timestamping, which are free with microsecond resolution.  If you insist on paying for a datestamp with horrible resolution, you could just use snailmail!  Their datestamps are even accepted by courts of law.

I'm well aware that bitcoin timestamping is not accurate, but it is really not an issue at all.

Since there is one new block every 10 minutes or so, globally bitcoin timestamping precision is more or less 10 minutes.

Imagine I make a nice audiovisuel file (movie, song, whatever).  I can sign and timestamp the hash of this file, and now all I have to do is to wait at least a few hours before releasing the file.  Then there is no way anyone could sign my file and timestamp it inside a previous block.  It's just as much impossible as it is impossible to steal some bitcoins from the block chain.

Accuracy is not the issue.  Robustness is.


PS.  I don't care at all about what courts of law accept or not as a proof for time.

Thinking outside the box here:

Moon, Mars land registrations using bitcoin.
In general digital lotteries using bitcoin.
Obviously, patents and copyright.


As a side note I don't like the arrogant attitudes of some of the posts in this thread.  Some people here talk like everything they say is fact.  As far as I know you are just an Internet user to me unless you have earned your respect like Satoshi.  Maybe they talk like that to get attention.  Not going to mention any names.

In this case you don't rely on the timestamp, but the sequence number, and you pay a high price by discouraging other people from using bitcoins.  Just read the other comments here.  There are so many other ways of doing what you describe in standard ways, free, accepted by courts, etc, and with precision allowing you to release the file a second later, that you should pause and ask yourself if this is a brilliant way to waste a good currency.

Btw, your hash isn't worth much if the hashing algorithm is broken.  You better sign and post the entire file, not the hash of it.  At least post more than one kind of hash of the file, if it is important to you.  The blockchain in Bitcoins make it impossible to change your hash, but your hash itself may be worthless because someone can claim that you have changed their work in subtle ways to make it match your hash.

All of this can be done out of the blockchain or in a separate blockchain if you insist on connecting it to Bitcoins.  Perhaps another blockchain demanding accurate timestamps, if what you want is timestamps.

I dont get why people want to introduce incidental things into the currency chain.
If you want a different purpose start a new project.

Using publications, blogs and so on are not that good.  It's not as robust as bitcoin would be.  Because it depends on the assumption that the used public editor wouldn't care enough to take advantage of his status.  Basically an agreement could be secretly done between one of this editor and a wanna-be counterfainter.  So essentially this method is good as long as it is not too much generalised and that it doesn't catch too much attention.  Also, such methods are not systematic.  You basically need to find a good source of digital entropy, and hope that it is reproduced enough in the cyberspace, so that you can make sure that your added data will be preserved there.  It's not systematic, and requires quite some human work.

I also don't understand why you consider using bitcoin for timestamping would "waste" the currency.  It's fondamentaly the same function that is used, only for different purpose.  Anyway I very much doubt the volume of timestamping transactions would be large enough to disturb the network.  As I see it, monetary purpose would be way larger than timestamping.


Well, if you question the security of the hash algorithm, then you question everything.  This is way too much a big hypothesis.  Especially if you consider the possibility of a collision, as you seem to do.


Doing a separate block chain specialised in timestamping of signed documents could be a possibility, indeed.  But I doubt their would be enough nodes to keep it running.  What would be the intencive for those nodes to mine ?  It is way much simpler to just use the current bitcoin network.

I don't get why someone wouldn't. If everything is set up and nothing can prevent it, why build a new one that will be weaker? Even if it did damage bitcoin that isn't an incentive that will keep people from doing it. If this is a problem for bitcoin then bitcoin isn't that good since it gives incentives, apparently, for exactly this kind of use.

I'm not saying that I think it will be a problem for bitcoin. I'm saying that problems for bitcoin are not an effective deterrent and you either need to consider that a weakness of bitcoin or simply not a problem. I can't make up my mind, but I'm leaning towards "not a problem".

Very true.


Satoshi has created some kind of a decentralised giant clock.  It's ticking at an approximative rate of 6 ticks an hour.  Such a clock that can't be controlled by no one in particular will necessarly have some use in the future.

Then don't use publications, blogs, etc.  Use e-mail, wikis, facebook, IRC (logged channel), snailmail, public syslog servers, fax via internet fax services, Twitter, etc.  There are limitless possibilities, and many are well suited to post the work in full.

No, it isn't.  The timestamps in the blockchain are not ment for timestamping Bitcoin transactions, just the blocks.

Btw, there is a race condition in your plan to post a hash of something in a transaction.  Someone who picks up the hash from your transaction can send a new transaction with the same hash embedded.  If both make it in the same block, you have no way of knowing who was first.  If the other one makes it into a hash before you, possibly by paying a higher fee, then you lost the race completely.  You have to encrypt your message to make it unreadable for others.

Timestamping transactions?

Collision attacks on MD5 are well known.  Find bits which can be flipped without changing the hash, flip, repeat.  The first collision attack on SHA-1 was published in 2005, and found a collision in only 2^63 operations.  Those attacks do not change everything, and the blockchain is immune to simple collision attacks due to it's length and the merkle hash on top.  The single hash you put in there as "proof" of something is not, since you don't need to change that hash.

You could pay the nodes mining the other chain with bitcoins for transactions.  Thereby using bitcoins as a currency, as it was always ment to be.

That's what I thought : you don't really understand how it works.

You are supposed to post a hash of the SIGNED file (in other words, the signature).   There's no point sending a hash of a file signed by someone else.

You have a something that works now?

This is not what you wrote here:
I assumed you signed it by your transaction (a key in your wallet) and timestamped it by the timestamp in the block it made it into.  This is the simplest explanation.  If you have a clear understanding of how this works which is more complex than what you wrote, I suggest you write it here instead of harassing people who read your posts.  Am I correct in that you want to use the timestamp in the block, or do you want to timestamp the hash in some other way?

I still don't understand why you want to discourage bitcoin users and make Bitcoins less efficient by putting junk in the block chain.

What happens when your timestamp gets pruned off the blocks' merkle trees?  Then it is useless.

I thought is was clear since we've already talked about that in an other thread.

I was obviously talking about a GPG signature.  But indeed a ECDSA signature would do.

So I make a signature of my text, compute the sha256 hash of this signature, turn it into a valid bitcoin address(there is a function to do that somewhere), and finaly I send 0.01 bitcoin to this address.

It doesn't cost the network more than a ordinary transaction would.


PS.  The thread where this has been discussed :
http://bitcointalk.org/index.php?topic=2077.msg28775#msg28775

You don't seem to know what you're talking about :)

http://en.wikipedia.org/wiki/Steganography

Though if I sent to you the following:

0.66 BTC
0.73 BTC
0.84 BTC
0.69 BTC
0.32 BTC
0.77 BTC
0.69 BTC
0.33 BTC

I would have failed -- not just because it cost me over 5 BTC (even before any transaction charges) just to send a lousy 8 bytes of data, but it would be easy to tell that I was sending data.  But as a channel for sending a message, in a pinch it might be useful.

You don't get it.  It's not steganography at all.  You don't really send any data to the network.  It is the same amount of "data" injected, whether you timestamp a "hello world" or a 1Go tarball !


It seems that I have to make an example to make it really clear.

So, I'm going to time stamp the tarball version of bitcoin, version 0.3.19.

First, I make a GPG signature of it :

$ gpg -s bitcoin-0.3.19.tar.gz

This creates a bitcoin-0.3.19.tar.gz.gpg file, whose sha256 sum is :

$ sha256sum bitcoin-0.3.19.tar.gz.gpg
9e3d69700386772814b0e8c9723d8162c8d88c94479dbd24f18f280b

I turn this hash into a bitcoin address using the convertor in bitcoin block explorer

$ wget -O - -q http://blockexplorer.com/q/hashtoaddress/9e3d69700386772814b0e8c9723d8162c8d88c94479dbd24f18f280b
1BehjJ4trLTY1G148PntLkzb99UYYg5qWEotEAGudWXaW

Finally, I send 0.01 BTC to this address.

$ bitcoind sendtoaddress 1BehjJ4trLTY1G148PntLkzb99UYYg5qWEotEAGudWXaW 0.01

Hum...  bitcoin tells me it's an invalid address.  There must be a bug, but you get the idea, right ?

You need to use a 160-bit hash. SHA-1 or RIPEMD-160, for example. You could also truncate the SHA-256 hash to 160 bits -- this generally gives nearly as much security as using the entire hash. Ensure that you give /q/hashtoaddress exactly 40 hex characters in order to receive a valid address.

For Bitcoin addresses, Bitcoin first does a SHA-256 hash and then does a RIPEMD-160 hash on the output.

I guess I should have included Jimbobway's message to indicate what my reply was a response to:


I've decoded the ASCII character that represents the amount sent in each of those 8 transactions:
0.66 BTC  = B
0.73 BTC  = I
0.84 BTC  = T
0.69 BTC  = E
0.32 BTC  = [space]
0.77 BTC  = M
0.69 BTC  = E
0.33 BTC  = !

That is steganography, no?  And that is using bitcoins in a new way?

+10

So you would have a timestamp that can be changed if you have access to the server.  No central authority is needed for Bitcoin timestamps.

And again, somebody with access to the server could change the time on the page.  Bitcoins solve the problem of what came before with no central authority needed. 

Or, how about this one ....

To facilitate Anonymous Voting

It wouldn't work where one person gets only one vote, but for popularity type voting, casting votes by way of Bitcoin would be an quick and easy way to hold a secret ballot vote.

Setting a specified minimum amount (e.g., 1 BTC) would give a disincentive for submitting too many votes.

e.g.
Those supporting plan A send to [bitcoin address A]
Those supporting plan B send to [bitcoin address B]

Personnaly I'd be ok with that but I'm pretty sure most people won't.   Ploutocracy hasn't been moraly accepted since ancient greece.

Winners' money is given to the losers as compensation imo.

Maybe this is not a new use of bitcoins, but I thought before of using stamps for emails. (Stamps as in old-fashioned letter stamps).

If we could have our emails stamped in some way with bitcoins, then one could configure ones mail reader to show stamped (and payed for) emails with a priority.

Suppose we payed maybe only a fraction of a cent per email, that would make it more expensive for spammers to reach out.

(You could still send your emails free but that would mean it would end up in the junkmail folder of the receiver)

Having a few billion emails stamped a year would mean a huge turnaround for the bitcoin systems.

As said before, this is not a new use, but the cheapness of bitcoin transactions might make it practical and possible.

I believe you're describing Hashcash.

Whats the one thing humans have that is limited ? It is time...

Bitcoin can be used to solve the "tragedy of the commons" where people see something having no cost and then abuse it.

People say all the time twitter should be decentralised.
An open source twitter that allows me to pay for longer messages if I want to do so would be beneficial. Also let me filter direct messages which have a bitcoin attached and I might read them because it says to me "your time is valuable". Call it an "attention mail" or something. If people think other's time is worthless they will abuse it constantly.

Twitter direct messages are broken. The service goes down all the time because it relies on a central server.

Can bitcoin form the basis for an ethical short messaging service where people's attention is valued as it should be?

Same here.
Merging bitcoin with some other completely unnecessary crap would be the worst idea of the century.
I would welcome a fork with open arms in such a situation.

If anybody wants to play, he should find himself a sandbox. We're doing serious buisness here, this is no place for toys.

Does a change need to be made to let this stuff in, or a change made to keep this stuff out?

Can you tell me more about why it matters if a transaction has extra meaning to someone else. How will you even tell, won't it look like a normal transaction? Only legit transactions can get in, right?

Sorry if I'm confused or missed these answers.

If someone wants to transmit arbitrary data, there is generally always a way.  For example, data may be encoded today in a standard transaction, probably around 32 bits per transaction, simply by specifying an amount such as "0.12345678".

However, that does not mean that we should encourage the use of additional, non-standard transaction types created for the express purpose of storing arbitrary data in the block chain.  For example, it has always been possible to tunnel the IP protocol over DNS; but that does not mean it is wise to do so.  No mainstream DNS server supports such behavior, even if the protocol itself does.

Some BitDNS proposals here describe operations such as storing DNS records themselves in the block chain, where each IP address or nameserver change would be propagated throughout the bitcoin P2P network, and be stored in the local storage of all bitcoin full-block-chain P2P clients.

My concern is putting unnecessary bloat in bitcoin transactions. Check this out:


OK, so 22 billion transactions per year. That gives us ~60 milion transactions per day, ~2.5 million transactions per hour, ~41000 transactions per minute and ~695 transactions per second.

Right now, bitcoin requires about 275 bytes of transfer/storage per single transaction, which gives us 190 972 bytes of transfer/storage per second, 687 500 000 per hour, and 16 500 000 000 per day. Yeah, that is 687 MEGABYTES PER HOUR and 17 GIGABYTES PER DAY.

If bitcoin is supposed to ever become LARGE like VISA or MasterCard, it has to be prepared to handle large amounts of transactions. And putting some additional crap in transactions will make the bandwidth/storage space requirements become VERY difficult for people who want to run their own clients (and i intend to).

If you add for example only 100 bytes to each transaction (not much, right ?), then total amount of space&bandwidth will increase by almost 40%. And 17 Gigabytes per day is already enough.

So there is no way to handle the growth? This seems like a problem whether other stuff goes in or not.

But that didn't really answer my question. Even if it is bad, how can it possibly be stopped? Aren't people talking about making normal looking transactions and interpreting them in a certain way? Are you suggesting future versions of the client should test all transactions for extra meaning and block them?

Yes, there is a way. Only put necessary information in the chain. Keep currency-unrelated stuff out, and it will be fine.


1. There is a mechanism already implemented to do that. Transaction fees. If there are too many transactions, per transaction fees my kick in automatically. However i don't know how does that  exactly work.
2. This cannot be completely stopped, but that is not a problem until bloat is kept out of official chain. As long as the tansactions are "standard", but hold some steganographic information in them, it's OK.


You overslept. That is exactly what version 0.3.18 is doing using isStandard() function. It filters out all non-currency transactions unless I am not misunderstanding something.

Transaction fees.

Whether the block chain is currency-only or currency+data, the result is the same:  transaction fees rise as overall block size increases.

More data == more expense (theoretically the block chain provides more value to more people, and is therefore more valuable)

It doesn't stop this:

You can't tell the difference, like grondilu showed.

We're not understanding each other.

I already pointed it out in when i was talking about Steganography. You cannot stop people from using bitcoin for other means than currency - because there is steganography, but you can limit it using currency fees and isStandard().

Anyway as i said, the less unnecessary data is in the chain, the better. More junk = greater bandwidth/storage requirements. And in case of bitcoin goes into micro-payments buisness, this will become a problem quickly.

Of course, and that is a kind of Steganography (http://"http://en.wikipedia.org/wiki/Steganography"), which i already pointed out.
Steganography = hiding additional information in seemingly "standard" data, such as music, video, images, and now - bitcoin.

But such a transaction is a standard transaction, which is no problem at all because it does not bloat the blockchain with extra data.
The problem which i was talking about is people trying to push extra non-currency data into the block chain and mainstream client, making every transaction bigger, which would increase storage and bandwidth requirements.

Okay, I'm pretty sure we agree. I don't think there needs to be extra room for data added either. But I do think normal transactions will be used to exploit special properties of bitcoin for non-monetary uses.

The problem with the 'block-chain' is that it is a serial process and there is NO way to get around that problem because to be 'deterministic' it must be a sequential process.

So as the demand to put things into the block chain exceeds the supply prices will rise.  The rise in price will be a market signal to increase the available bandwidth.

If I saw that the 'root' bitcoin chain was getting very expensive I would start a new 'currency' and an automated exchange with bitcoins.  The cost of using the new currency would be cheaper than the cost of using the 'reserve' currency (bitcoin). 

Eventually you would see 'clusters' of economic activity with synchronization points.

This encoding of a message by creating spend transactions of certain amounts was performed by the Bitcoinica thief to communicate the message "expect mass leak soon":

 - http://bitcointalk.org/index.php?topic=81045.msg895878#msg895878