I'm guessing it is a corrupted file.  

I have 9GB free on the drive but have most of the blockchain already.  I'm moving over to 750 GB of unpartitioned drive space that I've got.

I'm running with 24 GB of RAM, and my Internet connection is plenty fast.  I'm assuming the block chain isn't held completely in memory, is it?  I see it is currently at 27GB, so that could be a problem.

It seems bitcoin core is no longer syncing for me.  It's stuck at 12 weeks behind and is not processing any more blocks.  When I ran the program 2 weeks ago it was stuck at 10 weeks, and never dug into what was the problem.  But I'd like to move some coins around.

Is there a way to unstick this stuck?  I am on version v0.9.1.0

To be brutally honest, it was a waste of time and money for me to attend.  I could have stayed home and caught up on some much needed housework this weekend.  I also would have learned more spending 2 hours reading old messages on this forum than in the 12-14 hours I spent at the expo (not to mention travel time).

First off, hosting it at McCormick Place was total overkill.  The conference organizer clearly had little idea of what they were doing in choosing to go that route.  This is a conference center, the largest in North America and easily one of the largest in the world.  However they only had a tiny section of a hallway for exhibits and two medium sized conference rooms for sessions.  They could have hosted it at a swanky hotel  by the airport and it wouldn't have cost us locals $21/day for parking.  

Second, of the presentations I went to, only the regulation panel and bitcoin 2.0 panel had any tiny bit of insight that made it worth while.  Not nearly enough to justify spending two days to attend.  

Third, I talked to a few people who lived in the area and attended because they wanted to learn more about bitcoin.  Sucks to be them.  There was nothing at the conference that would have been geared towards educating people about what bitcoin is and how it works.  Aside from the ever present "TO THE MOON" bullshit that seemed to have been included in at least 1/3 of the presentations I sat in on.

It was small.  A few hundred people were there.  I understand it's a nascent industry, but I honestly would have thought there would have been more techies and other financial services sector types from the Chicago area just checking it out.  This tells me that people really aren't that interested in the concept.  

Most tech shows do a call for papers, and require presenters to provide a synopsis of their presentation.  The organizer then chooses among the most promising to speak.  I am pretty sure this guy just asked a bunch of start-up guys to come speak about anything, regardless of what they were going to speak about.   The content was so.... blech.

Group doesn't exist on MeetUp.  I'm interested, in something closer to me.

I registered a few weeks ago, and paid using Bitpay.  All I got back from Bitpay was an email that linked to a receipt.  But nothing that particularly identifies that I paid.

How will you folks reconcile users and who paid?  Do we just need to provide our email address at the conference? 

That needed digit grouping.

Thank you.  Wasn't trying to be that guy, but just wanted to make sure I understood correctly.

Is this a decent enough way to explain the Elliptic Curve Discrete Logarithm Problem for people without a math background (like me)?

This makes sense.  The people who got rich in the 1849 gold rush were the companies who produced the equipment to mine the gold.

I bought the USB miner just on a lark to just chug away and see what kind of return I got. A 1 THash miner would probably give me about 100% ROI if it can last for a few months.  But as more and more miners come online, the rewards are going to decrease rapidly.  And come next halving day, I sincerely doubt that transaction fees will increase sufficiently to make up for the 12.5BTC drop per block. 

I jumped into mining with a purchase of a $15 AntMiner USB chip.  I'm not and never had any belief I'd make much of a profit on it, it was mostly for learning.  But I'm wondering if it's even possible to make any profit.  

I'm currently getting 1.75 GHash/Sec.  From what I have received over the past few hours, as well as projects from various web sites, the lifetime earnings of this will be about $5.  That's earnings, not profit.  Cost+shipping will be about a $25 loss).  That's assuming BTC price remains stable, I'm not using any electricity, and a few other factors in favor of some kind of a profit.  

If that projection is accurate, than if I were to get a 1 THash unit at about $2,100 then I might expect a lifetime earnings of $2,800 or so.  Again, assuming BTC price is stable and not factoring in expenses like electricity, time spent working with the unit, etc.  

Is this about  right? Has mining become such a commodity right now that you might hope to recoup only a few percentage profit over time on a capital investment?

I think you need to do your own homework rather than asking to be convinced. Its a risky investment. It could continue to grow or it could drop to zero.

Do you have specific questions?

Isn't the maximum value of private keys based on the p of secp256k1, which is  2²⁵⁶ - 2³² - 2⁹ - 2⁸ - 2⁷ - 2⁶ - 2⁴ - 1 ?  It's close to  2²⁵⁶, but not exact.  Not to be pedantic, just want to make sure my understanding is correct.

So a private key is any number from 1 to  115,792,089,237,316,195,423,570,985,008,687,907,852,837,564,279,074,904,382,605,163,141,518,161,494,336.... or a little under 2^256.  Using the ECDSA, a public key is created that is anywhere from 1 to 2^160.  And, if I remember what I read elsewhere correctly.  For any of those public keys, there should be about 2^96 corresponding private keys.

Therefore....

1) If I have a bitcoin address of "1EQG7J2q4VfAgMBhetEj3cd3PNGYmBLHh" and I wanted to brute force finding a private key that corresponds to that, I could theoretically start with the number 1 as the private key, and increment by one each time, and on each iteration compute the public key (plus derive the address) and validate if the two match.  I would need to do this about 2^160 times until I found a match.  

2) If I did find a match, even if the new private key  did not match the original private key used to create address, I could create a transaction to transfer bitcoin to another address.

Are those two statements correct.  

I just need to find one of the 2^96 numbers of the 2^256 that hash into 1P1ou9XxdpdM35JdWYRE7CHRa6E6mU7ziV, and I'm living on easy street!  

Thanks.  This makes sense. 

Back in Dec I sent a small amount (.02 BTC) to two different addresses, a few bucks to a friend and a few to my android wallet.  These were sent from my Bitcoin-QT wallets.

I was looking at these today, picking apart the wallet.dat file and noticed that when those transactions occurred, the blockchain had recorded transactions like the following:

MyAddress  -> FriendsAddress (.02 BTC)
                -> AnReservedAddressInMyBTCWallet (.8283 BTC)

and

MyAddress  -> MyAndroidWallet (.02 BTC)
                -> AnotherReservedAddressInMyBTCWallet (2.43 BTC)


What is up with this?

r9gWP2eDimibtu5ypjU8iKD4gT2DV5nubd

This is useful if I know the size of blocks, and if block sizes are consistent across all virtual currencies. 

They found odd behavior and immediately took steps to correct it.  I'm not aware of anyone who reported any accounts compromised.

That's your first mistake right there.  I transfer all coins off of those wallets immediately as soon as I can.  

As for LastPass, I use it to store 1/2 of password, which is a 15-25 digit string.  The other half is one of several phrases that only I know which are indicated as a bit of text/numbers embedded in the stored password that get substituded out.  

So even if lastpass was broken into, they'd still have between 62^5 and 62^10 combinations to try to get to the completed pass.  I store the back-up wallet in a cloud drive using a variation of the password scheme I just told you.  

Ideally, I should also be storing this methodology (along with wallet back-ups) with a family member or lawyer in case I die, and keep the lastpass passwords in another location on a piece of paper that you would know but wouldn't make sense to others (or a bank vault like most people) in case lastpass goes kerplut - and my half of the pass phrases with someone I trust.

And to be honest, with the amount of coins I have right now, a crook could get more money by surprising me with a pipe-iron.

Can someone point out where I can find the total number of coins in circulation for LTC and PPC, and possibly even TRC (or whatever it's called).

And also, preferably, some sort of how those coins are currently distributed among holders (Many with a little, or a few with a lot).