Bitcoin Forum

Other => Off-topic => Topic started by: cbeast on April 04, 2012, 02:59:08 AM



Title: Heads or Tails?
Post by: cbeast on April 04, 2012, 02:59:08 AM
This poll is not about Casacius physical Bitcoinsm but the actual money we spend for our favorite Bitcoin stuff.


Title: Re: Heads or Tails?
Post by: Kettenmonster on April 06, 2012, 01:00:29 PM
Defies gravity and just keeps flipping, provided you speed it up properly (http://en.wikipedia.org/wiki/Escape_velocity).


Title: Re: Heads or Tails?
Post by: marked on April 06, 2012, 06:35:18 PM
surely flipping a coin increases its goxedness asymptotically to 1

marked


Title: Re: Heads or Tails?
Post by: tonto on April 11, 2012, 09:32:44 PM
Tails never fails!


Title: Re: Heads or Tails?
Post by: Kettenmonster on April 11, 2012, 10:35:52 PM
current majority: 40% Gets stolen by hackers
wtf?!? Hackers donīt steal! Them hackers point out weaknesses!

btw keep in mind: Money is never gone, itīs just elsewhere.


Title: Re: Heads or Tails?
Post by: organofcorti on April 12, 2012, 12:52:21 PM
Stupid question, but which side is heads, again?


Title: Re: Heads or Tails?
Post by: cbeast on April 12, 2012, 01:02:27 PM
Stupid question, but which side is heads, again?
Which side do you think it is?  :P


Title: Re: Heads or Tails?
Post by: organofcorti on April 12, 2012, 02:26:35 PM
Stupid question, but which side is heads, again?
Which side do you think it is?  :P

OK, you got me! I'll admit I have no idea which side heads is. Doesn't it depend on the current difficulty? Or network hashrate? Or something?


Title: Re: Heads or Tails?
Post by: marked on April 12, 2012, 03:04:50 PM
OK, you got me! I'll admit I have no idea which side heads is. Doesn't it depend on the current difficulty? Or network hashrate? Or something?

you think that is bitcoin that you are seeing? hmm... (c) senzonbakura

marked


Title: Re: Heads or Tails?
Post by: cbeast on April 12, 2012, 05:45:18 PM
Stupid question, but which side is heads, again?
Which side do you think it is?  :P

OK, you got me! I'll admit I have no idea which side heads is. Doesn't it depend on the current difficulty? Or network hashrate? Or something?
I suppose the analogy could be extended to such things, or even trading price. But then we would be speculating and that is yet another coin toss.


Title: Re: Heads or Tails?
Post by: organofcorti on April 12, 2012, 09:17:09 PM
Stupid question, but which side is heads, again?
Which side do you think it is?  :P

OK, you got me! I'll admit I have no idea which side heads is. Doesn't it depend on the current difficulty? Or network hashrate? Or something?
I suppose the analogy could be extended to such things, or even trading price. But then we would be speculating and that is yet another coin toss.

Analogy? You've stumped me again. I just wanted to play two-up with my bitcoins on the 25th. I'll need to know which side is heads.


Title: Re: Heads or Tails?
Post by: Unacceptable on April 12, 2012, 10:03:06 PM
Stupid question, but which side is heads, again?
Which side do you think it is?  :P

OK, you got me! I'll admit I have no idea which side heads is. Doesn't it depend on the current difficulty? Or network hashrate? Or something?
I suppose the analogy could be extended to such things, or even trading price. But then we would be speculating and that is yet another coin toss.

Well,when I "flip" my coins,I always get more of em  ;D


Title: Re: Heads or Tails?
Post by: ladida on September 15, 2012, 06:27:50 AM
rolls under the sofa, almost every single time ... I suck at coin flipping -.-


Title: Re: Heads or Tails?
Post by: goodlord666 on September 15, 2012, 07:22:23 PM
Wait a minute.

Would coin tossing with a bitcoin transaction actually be possible?

Couldn't you use any random data generated by a transaction to determine either state '1' or '0'? One that's publicly visible and unpredictable of course.




Title: Re: Heads or Tails?
Post by: organofcorti on September 16, 2012, 07:16:23 AM
Wait a minute.

Would coin tossing with a bitcoin transaction actually be possible?

Couldn't you use any random data generated by a transaction to determine either state '1' or '0'? One that's publicly visible and unpredictable of course.




Maybe. I don't see how you'd get the data to stay on the kip and the flip effectively. It would totally suck for two-up. I'm sticking with the old pennies.


Title: Re: Heads or Tails?
Post by: goodlord666 on September 16, 2012, 03:57:01 PM
Wait a minute.

Would coin tossing with a bitcoin transaction actually be possible?

Couldn't you use any random data generated by a transaction to determine either state '1' or '0'? One that's publicly visible and unpredictable of course.




Maybe. I don't see how you'd get the data to stay on the kip and the flip effectively. It would totally suck for two-up. I'm sticking with the old pennies.

Isn't a transaction ID created at random?

Couldn't you use that to determine 1/0?



Title: Re: Heads or Tails?
Post by: scintill on September 16, 2012, 05:06:45 PM
Wait a minute.

Would coin tossing with a bitcoin transaction actually be possible?

Couldn't you use any random data generated by a transaction to determine either state '1' or '0'? One that's publicly visible and unpredictable of course.

Maybe. I don't see how you'd get the data to stay on the kip and the flip effectively. It would totally suck for two-up. I'm sticking with the old pennies.

Isn't a transaction ID created at random?

Couldn't you use that to determine 1/0?

in order to calculate the ID hash of the Tx that is used in the Merkle Tree, one needs to SHA hash the whole Tx message as defined in the Protocol Specification wiki page (https://en.bitcoin.it/wiki/Protocol_specification#tx) twice.

So, it is not "random" per se.  Since the creator of the transaction has some choice of what inputs to use and complete control of what outputs to use, they could keep trying different combinations until they got a txid meeting certain criteria (such as being even or odd, for a coin flip.)

Edit: yes, more involved criteria for the txid are harder to find (it takes more tries), but even/odd is easy.


Title: Re: Heads or Tails?
Post by: goodlord666 on September 16, 2012, 07:51:06 PM
^if that were the case then using the same inputs and outputs with the same send amounts twice would also generate the same txid twice. but that can't be.

what makes a txid unique?






Title: Re: Heads or Tails?
Post by: scintill on September 17, 2012, 01:43:06 AM
^if that were the case then using the same inputs and outputs with the same send amounts twice would also generate the same txid twice. but that can't be.

what makes a txid unique?

The fact that you can't use the same input(s) twice -- that's what a double spend is.  An input comes from someone else paying you (or coins being generated), and can only be spent once, spending the whole value at that time. 

If you don't want to actually spend the whole value to other people, you can send the change back to yourself at a "change address."  (Clients do it automatically.)  That change address can then be used as the input for another transaction.


Title: Re: Heads or Tails?
Post by: goodlord666 on September 17, 2012, 03:07:03 AM
scintill,

blockchain.info offers a "Time received" for each transaction. Any chance it gets that info from the blockchain? (But it doesn't seem like it does to me)



Title: Re: Heads or Tails?
Post by: scintill on September 17, 2012, 05:31:17 AM
scintill,

blockchain.info offers a "Time received" for each transaction. Any chance it gets that info from the blockchain? (But it doesn't seem like it does to me)

Blocks have a timestamp, but that time is probably taken from when blockchain.info's node(s) first saw the transaction, as they do for IP addresses they saw blocks/transactions from.


Title: Re: Heads or Tails?
Post by: goodlord666 on September 17, 2012, 10:56:32 AM
Yeah that's what I expected. It really does look like a transaction doesn't offer data random enough for a reliable coinflip. What a bummer, really.

Out of pure interest:
where does a block get its timestamp from?



Title: Re: Heads or Tails?
Post by: scintill on September 17, 2012, 04:47:07 PM
Yeah that's what I expected. It really does look like a transaction doesn't offer data random enough for a reliable coinflip. What a bummer, really.

Out of pure interest:
where does a block get its timestamp from?

According to Joel Katz in this thread (https://bitcointalk.org/index.php?topic=27628.0), miners/pools set the timestamp.  The Satoshi client seems to require blocks broadcast to be not more than 2 hours into the future, and not earlier than the median of the last 11 blocks' timestamps.


Title: Re: Heads or Tails?
Post by: goodlord666 on September 18, 2012, 01:15:46 AM
Ingenious.



Title: Re: Heads or Tails?
Post by: SRoulette on September 18, 2012, 08:12:15 AM
according to our game (http://satoshiroulette.com/coinflip/) there is a 1/100 chance of it landing on its side :P