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4941  Bitcoin / Hardware / Re: MeSarah spew from BTCFPGA thread on: November 05, 2012, 12:33:30 AM
FWIW, BFL wrote me to say:  "Mesarah has nothing to do with BFL and I would appreciate it if such a connection wasn't implied by the moderators of bitcointalk",  and thats a request I think is completely reasonable.

For all I know MeSarah is some kind of crazy counter-agent that is maximally obnoxious in BFL's apparent favor just to make BFL look bad.  Then again, I have to say I also would have had the opinion about Inaba's posts in the last month, so take my crazy conspiracy theory guesswork for what it is: Not terribly reliable.

Frankly, the kind of trouble I've seen people cause is the sort that comes only from seeing the misfortune of others, of creating argument and drama, and not from promoting one interest or another. Chaos has no affiliation but its own.

In general we should judge participants in our community by their own actions and not by those of their sometimes unfortunate supporters.  I've certainly had my share of moments cringing at some of the agreement I've received.
4942  Bitcoin / Hardware / Re: High Efficiency FPGA & ASIC Bitcoin Mining Devices https://BTCFPGA.com on: November 04, 2012, 08:00:09 PM
Guys MeSarah is gone, and has been for a while, please quit re-quoting him and let it die.
You might even want to delete these last couple posts.
MeSarah posted today. In this thread.
Yes. And its been moved out of the thread. STOP AMPLIFYING IT.
4943  Bitcoin / Hardware / Re: MeSarah spew from BTCFPGA thread on: November 04, 2012, 07:44:06 PM
@ gmaxwell, you have no proof that BFL is, paying these trolls,

Funny, I didn't mention which trolls I was talking about or who might be paying them.  I'm glad you could help people with your opinions on the subject.

Quote
as you put it and insinuating so is libelous. Sarcasm is not protected speech like parody is. gmaxwell sense the Bitcointalk forum has given you moderator status that makes you a legal agent for Bitcointalk and makes Bitcointalk liable for your comments. Bitcointalk has no Terms of Service that would insulate it from your comments and thus no protection from libelous statements made by it's moderators.
gmaxwell, you have taken away Bitcointalk's safe harbor on this issue.

You are very thoroughly confused about the law. But hey, feel free to send me the contact information for your attorney.  Mine wouldn't mind having a word with yours.

Quote
Don't worry I took a screen shot and uploaded to the internet where it's date can be easily verified.

Please provide hyperlinks. Note, I have not authorized and do not authorize public duplication of my writing. If you wish to make private copies for whatever purpose be my guest.

And as I previously directed— I would remove your posts if you continued to repeat the same material and I have done so, as promised... but your post was too funny to delete completely.
4944  Bitcoin / Hardware / Re: High Efficiency FPGA & ASIC Bitcoin Mining Devices https://BTCFPGA.com on: November 02, 2012, 11:47:43 PM
I'm now removing further "MeSarah"'s posts from this thread and wll remove them generally anywhere in the mining subform at least so long as they keep repeating the same things. As it stands these repetitive posts off-topic and over the top and I'm reasonably convinced that no one here is interested in hearing more of them.

Let me know if I've made a mistake. Alternatively, if whomever is paying these trolls wants to send me a substantial kickback I _may_ be persuaded to look away and allow the insanity to continue: 136H7e7oHYtddM9iPNLG8ZGDqZvme2ogUn  Tongue

Also— I _strongly_ recommend using the ignore button when you see people that are constantly idiots, dishonest, or otherwise abusive. You can still view the posts if you must for context. Ignore is like a distributed ban and the text turns yellow as more people do it, signaling to other people that the community considers that person to be a waste of time or worse.
4945  Other / CPU/GPU Bitcoin mining hardware / Re: BOUNTY: BFL SC die size (20BTC) and process node (20BTC) on: November 02, 2012, 04:49:26 AM
It's simple, those that know have an NDA.
Or they are honorable people who value the trust and respect gained from not breaching confidentiality for some minor prize even absent a formal contract.
4946  Bitcoin / Development & Technical Discussion / Re: BIP Draft - Instant Partial Confirmation on: November 01, 2012, 07:39:30 PM
P2Pool does not charge fees, and it may well survive a lot longer, but again - there's a certain simplicity to just mining solo that may be appealing for large-ish miners,

Currently P2pool is simpler to run than solo mining, though this is an artifact of ~no larger miners except Luke bothering to submit patches to  full node software for mining scalability.

Quote
and I think eventually all miners will be somewhat large. I doubt we actually need more than 1000 distinct miners as long as they're distributed around the globe.
Your opposition to long term real decentralization in Bitcoin is well established at this point.  I think as a community we need to start speaking up emphatically against these positions. I hope you will not take it personally when I do, because I have great respect for you no matter how much I disagree with you on this subject.

If Bitcoin were only to have 1000 distinct non-trivial mining entities then I believe Bitcoin would be worse than pointless.  With so few entities having a veto over the validity of transactions it would be substantially more centralized than any of the largely existing widely used currencies— as there are are far more bank like entities than that for any major currency, and unlike bitcoin other currencies have cash transactions which are more reversal resistant. The cost and complexity of bitcoin is not justified if it doesn't provide a solid advantage over highly trust centric (semi-)centralized systems like the USD.

From a technical perspective: If you were only to have 1000 entities the Bitcoin consensus algorithm is fundamentally wrong:  The stochastic POW chain consensus provides slow and unpredictable eventual consensus. A consensus of 1000 entities can be accomplished far more inexpensively, rapidly, and reliably by identify them and using a majority vote with digital signatures. There are places for systems with this kind of security property, and they are the sorts of things OpenTransactions seek to create (potentially ones with much better scalability than the broadcast based Bitcoin system).

It would certainly be nice if there existed a global, thoroughly distributed, cheaply validated, medium of exchange which could enable trade between distinct scalable and fast confirming federated systems... but it won't be so if Bitcoin tries to become everything to everyone with forcing users through services providers and limiting miners to those who can handle gigabits of bandwidth for multigigabyte blocks.

Fast provably strong confirmations are not something the Bitcoin consensus algorithm can do without sacrificing the things that make Bitcoin worth having and we shouldn't be afraid to admit this.
4947  Bitcoin / Development & Technical Discussion / Re: Faster payments should be priority #1 on: November 01, 2012, 04:56:56 PM
There still is a potential for another double spending attack called the Finney attack, but that is very uneconomical, as it is very expensive to carry out and is simply uneconomical for a thief to try to use it for low value transactions like a VPN subscription.
Please don't downplay the finney attack.

It's a non-issue in this case because— as mentioned— they can just cancel the service if the payment doesn't go through. This would let them get instant turnon and security against all kinds of attack. For the purpose of this thread it's really the end of the discussion.

But the finney attack is not terribly uneconomical now that there are services where you can buy hashpower from dimwitted greedy miners for small premiums over their value.  The finney attack is also not the only relevant concern for 0/confirmed:  conflicted transactions are not broadcast (and simply broadcasting them has serious DOS risks) so there may be a substantial portion of the network that prefers a conflicting transaction and yet you won't hear about it.  Moreover, AFAIK no existing node software does anything _useful_ even if it does hear a conflict such as expose it to the user. Again, in this kind of case it doesn't matter, but I strongly disagree with downplaying it generally.
4948  Bitcoin / Development & Technical Discussion / Re: "Hash 0-0-0", "Hash 0-0-1", "Hash 0-0", "Hash 0-1", "Hash 0", "Hash 1", "Top Has on: November 01, 2012, 03:42:57 AM
Interesting. That solves the political problem with the idea that individual P2Pool miners would be forced into including certain transactions. Instead of being forced to include certain transactions, they just wouldn't be able to include one that conflicts with past blocks on the sharechain.
It doesn't really.

The expectation of solo mining is the same as pooled mining. If you'd like to split off and try to mine a conflicting transaction you can and you won't lose any coin on average— you'll even gain if the conflict has higher fees.
4949  Bitcoin / Development & Technical Discussion / Re: "Hash 0-0-0", "Hash 0-0-1", "Hash 0-0", "Hash 0-1", "Hash 0", "Hash 1", "Top Has on: November 01, 2012, 12:12:38 AM
I believe it has been touched upon somewhat already, but what about if - instead of having to trust miners to include a transaction into a block - the client is sent blocks that have difficulty of 1/600th of the Bitcoin block chain's difficulty? This would produce, on average, one block (with 1/600th the difficulty of the block chain) every one second (provided all the miners participate).
It's not a guarantee because the inclusion isn't fixed like it its when a transaction is actually mined, a miner could stop at any point.  Perhaps you could imagine some kind of system for discouraging that, but it would need a consensus mechanism... and would have to force all miners to mine the same txns (or at least no conflicts)

P2Pool now does this— miners exposing what they're working on in p2pool shares with no enforcement— however.
4950  Bitcoin / Development & Technical Discussion / Re: How long would it take to brute force 256 bit AES passwords on: October 31, 2012, 01:18:00 PM
Did you miss the bolded part?  Or did I misunderstand you and you have a rainbow table of all  9,967,884,244,759,920,000,000,000,000,000,000,000,000,000 combinations of a 12 digit passphrase and 64bit salt values?  I guess "desk" is the name of the planet which you converted into a supercomputer. Sweet.  I will start using 128 bit salt values (only those larger than 2^64-1) and make that precomputation worthless.

I did— but no need to be a smartass about it— especially since you're drawing the wrong conclusion.

The existence of this rainbow table _proves_ the feasibility of brute-forcing that entire space for a single salt. I _happened_ to have a rainbow table, but for the point I was making I might have well said that I brute-forced a single password of that size on my GPU farm.

So sure, the salt means the attacker couldn't lower their costs through precomputation, but if you have high value data (e.g. a bitcoin private key they _know_ has a lot of funds assigned to it) then they really could search such a large space unless you had a quite costly KDF.

And I agree in combination your advice is good, I'd just prefer that you hadn't repeated the 8 characters == good myth, which is terrible advice in isolation as it's normally applied. Tongue
4951  Bitcoin / Development & Technical Discussion / Re: Satoshi client wasting bandwidth, getting blocks multiple times on: October 31, 2012, 02:58:57 AM
I have 16 connections at present and am downloading blocks off the main network. I have noticed what appears to be my copy of Bitcoin receiving the same blocks multiple times in the logs:


This is generally a known behaviour. What happens is that you are doing the initial block download forward, and then a new block happens on the network and you try to connect it (backwards) to your chain... so you start pulling  and pulling and before you make it all the way back there is a new block on the network.. and you sweep over them.

IIRC it's not actually downloading them twice, but they show up in invs and you note you already have them and don't getdata them.
 
4952  Bitcoin / Development & Technical Discussion / Re: How long would it take to brute force 256 bit AES passwords on: October 31, 2012, 02:55:21 AM
As a developer you can implement a large salt and could require a minimum of 8 characters (don't impose special char requirements).  At that point brute force and precomputation are off the table; so the largest risk comes from dictionary or modified dictionary attacks.

You're saying a number of good things mixed with absolutely terrible things. I have exhaustive 12 character (alphanumspace) md5 rainbow tables sitting on a disk here.

With a fast KDF you need a fair bit more to be sufficiently strong.  And you certainly can't count on a user constructed string being sufficiently random really at any length.  People can't reason about entropy, and they can't reason about attackers that can do a billion attempts per second per gpu and have powerful statistical models.
4953  Bitcoin / Development & Technical Discussion / Re: is this a Satoshi client bug in an old transaction ? on: October 28, 2012, 06:55:18 AM
I am here to help, not to fork.
Using your example: for a while HTML was defined by Netscape but that did not save us from the Microsoft fork.
Hundred pages of standard did not work there either.
What might work is a set of test suites that major implementations and new releases have to pass. I am willing to contribute to such.
I didn't mean to discourage your work, I was just suggesting extreme caution because there are many subtle features which are hard to test and must be exact.

Diversity is good and may help discover issues.  But as Gavin was saying and as I like to point out: The most dangerous kind of failure in bitcoin isn't an implementation bug— any blockchain validation inconsistencies in widely deployed implementations are significantly worse than pretty much anything other than a full private key leak or remote root exploit... and are even harder to avoid.

There are many useful 'test' cases in the mainnet chain and in the testnet chain, but those only test valid blocks. Bugs that accept thing which should be rejected wouldn't be found by those.  Matt has been working on a test feeder tool as part of his effort to make full node support for bitcoinj which is very promising. There are also tests included with the reference software. There needs to be more of them.



4954  Bitcoin / Development & Technical Discussion / Re: is this a Satoshi client bug in an old transaction ? on: October 27, 2012, 07:27:46 AM
I think the problem is that the bold byte at the end of the signature, that should be 01 for SIGHASH_ALL. The value 00 does not map to any flavor. IMHO this is/was a "bug" in the Satoshi client
Just some poorly documented behavior, if you'll note there is no explicit mention of SIGHASH_ALL in the script code; SIGHASH_ALL is what you get when it isn't the other things.

If you implemented based on material in the wiki I would be concerned about the correctness of your implementation unless compared very carefully with the reference code and tested thoroughly because of the many possible sources of little quirks like this.
4955  Bitcoin / Development & Technical Discussion / Re: Is a nodes connection map feasible? on: October 27, 2012, 04:14:26 AM
Ok it is not feasible in a way of knowing 100% the exact connections. But in places like Australia, New Zealand, Japan ect where the density of nodes is small (nodes are isolated from the major node volume in Europe and USA), can node connections  be estimated with a good approximation?
Are any secret nodes that can not be detected on the btc node map?

Why do you assume those nodes are isolated? They are assuredly not— the software makes some effort to form topology-diverse connectivity and beyond that the network is randomly wired.

The overwhelming majority of nodes are 'secret'.  Nodes which do not accept incoming connections never have their addresses visible except to the nodes they directly connect.  Non-listening still function as complete nodes relaying transactions and blocks even though they aren't directly observable.

There are also a fair number of nodes which connect over Tor, and a number of nodes which are only inbound reachable as tor hidden services.

The bitcoin distributed algorithm is also not married to the peer to peer protocol, it's perfectly reasonable to link nodes via alternative means— e.g. bulk transferring blockchains (via https, scp, torrent, etc) is fairly widely done. People could even ship around transaction steganographically embedded in cat pictures. (and I've seen transactions being transported via IRC and pastebin).

You could certainly make measurements of the public stuff and infer some likely things about the hidden connectivity by things like transaction propagation times... but you can't reliably measure much of it.
4956  Bitcoin / Hardware / Re: Avalon ASIC Development Status on: October 26, 2012, 10:43:08 PM
No one knows if they are ready because no one has a working asic to test.
The BFL singles had issues with pools and clients when they first came out. They still don't work well with p2pool because of how the bitstream works.
It's quite easy (two lines changed or so) to modify pool software to accept 'difficulty 0' shares, and a regular cpu miner to consider every attempt a winner.. by doing this you can produce rates enormously faster than any asic.  If you're board its only a few more lines changed to fork testnet or bitcoin and mine a bunch of fake blocks to test the whole system. 

There may be some burps in practice but you can certainly get some reasonable testing in.
4957  Bitcoin / Development & Technical Discussion / Re: Testnet block reward halving on: October 26, 2012, 05:31:27 PM
What happens on testnet when the production block reward halves?
Are there separate rules that govern reward halving on testnet?
Same as Bitcoin.

If someone has a prerelease ASIC miner at 60GH it should only take 5 HR or so to push testnet3 to the halving if using a little time warping. I think this would be a fun test and I'd be glad to help with it.
4958  Bitcoin / Bitcoin Technical Support / Re: Riddle me this ...Payment sent to correct address recipient on: October 26, 2012, 01:42:01 AM
When in doubt, verify with Blockchain.info or BlockExplorer.com
The blockchain never lies.
Which is how you can tell that I have been paid all the bitcoins:  https://people.xiph.org/~greg/21mbtc.png

The blockchain itself doesn't lie, but websites with blockchain in their name aren't the blockchain. They're websites and they can lie and have lied in the past.

Seriously, depending on some centralized services is not a good idea. Every Bitcoin client itself has an independent view of the blockchain.  Does the transaction in question have a bunch of confirmations (e.g. on the order of 6 per hour since you made it)? if so — it's settled.  If the far end says they don't see it then something is broken there or you paid the wrong address, or they're scamming you.

4959  Bitcoin / Hardware / Re: Avalon ASIC Development Status on: October 25, 2012, 12:09:54 AM
If your words are taken literally, then the ASIC sellers are selling people very expensive lemons that will take a year or more to get their investment back....and then.....*barely any profit* per month.
What kind of major business expenses pay themselves back— passively no less!— in just a year?   Perhaps 7%/wk is more to your liking? Those tastes are catered to in other parts of the forum.

There are major risks in mining— including the risk that all that fancy hardware could be worthless before it arrives due to a loss of interest in Bitcoin, security flaws, legal attacks, etc. Or things like breakthrough optimizations for SHA256^2 allowing massive speedups on equal process or someone somehow doing a major run a vastly better process... just to name a few.

Meanwhile y'all have been ordering devices without concrete specs (including BFL customers— a substantial amount of pre-ordering happened when they were saying nothing about power at all!) which makes concrete reasoning about returns impossible if uncertainty about the future difficulty and exchange rate hadn't already made it impossible.

And after that, you're worried about some months difference in payback timeframes for some estimates?  Suicidal.  I hope no one has put money into these asic preorders that they can't afford to lose.
4960  Other / CPU/GPU Bitcoin mining hardware / Re: BOUNTY: BFL SC die size (20BTC) and process node (20BTC) on: October 25, 2012, 12:00:58 AM
Inaba, you cannot get paid for that, because...
Both of these bounties become null and void if BFL releases the figures themselves.
It was very craftily formulated to not let you earn a single satoshi. Wink

If Inaba tells me the figures but not in public then I can collect.  I'll only charge 50%, how about it Inaba?
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