Is it possible to make secure bitcoin transactions offline?
In direct contradiction to what Foxpup just told you, the real answer is yes but.... The OP specifically asked about secure transactions, as in safe from double-spend attempts. Accepting transactions offline (as in, actual signed transaction data, as opposed to physical bitcoins) flat out cannot be done in a secure manner as that requires either a connection to the Bitcoin network or a trusted connection to someone who does in order to verify that the transaction is not a double-spend. Now any double spend attempt is technically difficult, so it would be easy enough for a vendor to accept bitcoins for a fast food meal or something else along those value lines; because the relative difficulty of a double spend attempt even when the attacker knows that the vendor can't have a live connection (Internet kill switch?) would outweigh the value of the fraud.
I fail to see your logic. A double-spend attempt is technically trivial to perform; the hard part is ensuring the vendor doesn't realise it's a double-spend until it's too late. If the vendor is known to not have a connection to the Bitcoin network, this is easy: pick up goods from the store, "pay" the vendor, go home, send a double-spend to yourself, wait for your double-spend to be confirmed, then wonder what the look on the vendor's face will be when he eventually tries to broadcast your original transaction. |
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Is it possible to force the sources.list addresses to use a host file instead of DNS?
I'm pretty sure the hosts file is always prefered over the network's DNS server anyway, though this probably can't be relied upon if you suspect a rootkit. You can, however, put the repo's IP address directly in the sources.list file, eg: deb ftp://130.89.148.12/debian/ squeeze main contrib non-free (though this also shouldn't be relied upon if you've got a rootkit) Can tzdata be removed from Ubuntu without breaking it's ability to function?
No. What's tzdata got to do with anything anyway? |
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I'm trying to find out if bitcoin can replace cash and I'm having an important question about that right now, probably because I don't understand how a wallet's balance is stored:
A wallet's balance is not "stored" anywhere. Bitcoins exist purely as transactions, which are stored in the blockchain. Each transaction contains a reference to one or more previous transactions, eg, if someone sends you 10 BTC, you can create a transaction that sends those specific 10 BTC to someone else, after which the transaction in which you received the 10 BTC is considered "spent" and cannot be referenced in future transactions (trying to spend a transaction which has already been spent is called "double-spending" and is invalid). Note that this 10 BTC must be spent entirely in one transaction; if you want to spend (say) 8 BTC, then the transaction will be split into two parts: 8 BTC goes to the person you want to send it to, while the remaining 2 BTC is sent to yourself as "change". A wallet's balance is simply the sum of all unspent transactions that have been sent to it. Is it possible to make secure bitcoin transactions offline?
No. To verify that a transaction is valid, it is necessary to ensure that the previous transaction(s) which make it up haven't been already spent. This is only possible with an up-to-date copy of the blockchain, and even then it is necessary to wait until the new transaction is mined into a block (at which point it is considered "confirmed"), since until a transaction is confirmed, it may be invalidated by a double-spend in the future. I know transactions can be stored and flushed to the network later on, but does this mean that offline there is no verification possible of whether the sender actually has enough bitcoins to make the transaction? So... say, there is no internet available. I imagine that if someone who's standing in front of me buys from me and they try to make a transaction they cannot make to me (because their wallet does not have the required bitcoins available), I can only find out the transaction was not valid (it failed) after I exported the transaction online to the bitcoin network? I assume that a negative balance is not possible.
Correct. Without a connection to the Bitcoin network, there is absolutely no way to know whether a transaction sent to you is valid. |
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A coin where all the blocks are generated in the first block? Of all the crazy ideas for reducing blockchain bloat, this one ranks somewhere in the middle.
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The rootkit would make that file appear to be normal; that's what they do.
If you can boot from a known-good live CD then you'll be able to mount your root partition and see how that file really looks, before the rootkit has a chance to run and start masking itself.
I'm going to have to do this for sure. All of the Linux tools I've used are coming up empty, top and the like, yet the system responds as if it is overloaded by too many processes. When I do this, strace, I found out why there is nothing in ld.so.preload  : access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3still looking... Edit: RKH {Warning} Is this bad? Warning: The command '/usr/sbin/adduser' has been replaced by a script: /usr/sbin/adduser: a /usr/bin/perl script text executable
Warning: The command '/usr/bin/ldd' has been replaced by a script: /usr/bin/ldd: Bourne-Again shell script text executable
Warning: The command '/usr/bin/lwp-request' has been replaced by a script: /usr/bin/lwp-request: a /usr/bin/perl -w script text executable
Warning: The command '/bin/which' has been replaced by a script: /bin/which: POSIX shell script text executable
Checking for hidden files and directories [ Warning ]
Warning: Hidden directory found: '/etc/.java'
Warning: Hidden directory found: '/dev/.udev'
Warning: Hidden directory found: '/dev/.initramfs' Yes, that looks really bad! Re-install your OS before it's too late.  It's perfecty normal. My known-good MEPIS 11 installation has exactly the same setup: $ file /usr/sbin/adduser /usr/bin/ldd /usr/bin/lwp-request /bin/which
/usr/sbin/adduser: a /usr/bin/perl script text executable
/usr/bin/ldd: Bourne-Again shell script text executable
/usr/bin/lwp-request: a /usr/bin/perl -w script text executable
/bin/which: POSIX shell script text executable
$ ls -d /etc/.* /dev/.*
/dev/. /dev/.initramfs /dev/.udev /etc/.. /etc/.pwd.lock
/dev/.. /dev/.initramfs-tools /etc/. /etc/.java
My known-good Debian installation is identical except it does not have /dev/.initramfs or /dev/.initramfs-tools: $ file /usr/sbin/adduser /usr/bin/ldd /usr/bin/lwp-request /bin/which
/usr/sbin/adduser: Perl script, ASCII text executable
/usr/bin/ldd: Bourne-Again shell script, ASCII text executable
/usr/bin/lwp-request: Perl script, ASCII text executable
/bin/which: POSIX shell script, ASCII text executable
$ ls -d /etc/.* /dev/.*
/dev/. /dev/.. /etc/. /etc/.. /etc/.java /etc/.pwd.lock
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hey new to the whole tor and bc thing. want to sell some items but how do you convert btc to cash?! or dont you do that?
There are several currency exchanges where you can sell your bitcoins for cash (this is also the same way most of your customers will have obtained their bitcoins in the first place). |
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The amount of money made till now isn't that much. How do you mean, the amount of money made till now? That's easy: 9286150 BTC. And it's supposed to take 100 years to reach 21 million? I don't see that happening Bitcoin production follows a geometric progression:  Every four years, half of the remaining bitcoins are mined. The number of bitcoins in existence gets ever closer to, but never quite reaches, 21 million. If bitcoins were infinitely divisible, the number of bitcoins in circulation would keep increasing forever, but still never reach 21 million. But since bitcoins are not infinitely divisible, creation of new bitcoins will cease when the block subsidy drops from 0.00000001 to 0.00000000, at which point the number of bitcoins will be fixed at exactly 20999999.97690000. This will happen sometime around the year 2140. |
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I think bitcoins will succeed only till the mining process finishes. Then all the people invested in it will be the really f*gs, cos, nobody is going to buy their bitcoins and the price will stay the same forever until they quit this shit  . That's why I sell everything i made every day. The positive side of whole sh*t is that those people that will stay at last with some numbers and many lost real money will actually help world economy by losing those dollars, euros etc. The mining process will never finish (barring some kind of apocalypse, of course). The block subsidy will eventually drop to zero (sometime around the year 2140), but the block subsidy is not the only mining reward: miners also receive transaction fees, which will provide sufficient incentive for miners to continue their efforts after the block subsidy has ceased. |
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No. Everyone already learnt their lesson from SC2. |
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... customs has a scanner that sounds off alarms if plant material is detected(Or scanner blocking material), and all incoming mail goes through it
Doesn't most incoming mail consist entirely of plant material (paper) with only trace amounts of non-plant material (ink)? |
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In the standard client, if you enter an invalid address, the payment will refuse to send, and the address in question will be highlighted in red. Since bitcoin addresses include a checksum, the chance of a misspelled address being accepted as valid is about 4 billion to one against, so this isn't something you should worry about. Additionally, the standard client will autocorrect the easily confused characters 0,O,I,l to the correct o and 1. (In case you didn't know, the former characters are not valid in Bitcoin addresses, precisely to avoid accidental confusion with the latter characters).
If you only misspelled the label, it's no problem, as the label only adds the address to your address book (it is not sent as part of the transaction), and you can rename addresses in your address book at any time.
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The devices hold private keys on them. These can be backed up via the company’s website, but it is not necessary to ever interface with the company in order to use the device.
If you can't back it up yourself, it's a weakness. It should be able to display the private keys or a seed on the screen so you could take a picture of it. +1 |
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The question is how a layman measures "fluctuation".
If he comes today 1 hamburger = 1 USD, and tomorrow 1 hamburger = 1 USD it means for him USD is stable. In this layman sense USD is stable against almost everything.
Is it possible to sell hamburgers today at the same price as yesterday if we use BTC? Will it be good for seller? for buyer?
Are you suggesting that we use the Big Mac index as measure of volatility? Though I still prefer Pizza Purchasing Power: how many pizzas you can buy for 10000 BTC at a given point in time. It looks like we're up a few pizzas this week.  |
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ok bitcoin has not been hacked as a scource code, but it is still thinkable, while the Euro cannot be hacked in any way. How do you want to hack a bill?
How would I hack a bill? Well, I suppose I could let a bankrupt government print more of them, thereby reducing the value to almost nothing, but that's not likely to happen anytime soon... wait, never mind. |
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But the Olympics is not just anyone, they are state sponsored entitiy.
IMO, this is an illegal state aid under EU single market rules.
No they're not. The International Olympic Committee is a private non-profit organisation. The only "state sponsorship" they recieve is the bids to host the games in a particular country, which is really no different from states "sponsoring" other private organisations through various subsidies and contracts and other shady practices. |
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IANAL, but I'm pretty sure it is legal. As a general rule, people are free to accept or decline whatever payment methods they want, with the exception that legal tender must be accepted as a settlement of pre-existing debt (though other methods of payment may be accepted if the creditor agrees). Compare how eBay forces sellers to accept PayPal, which is also perfectly legal, apparently.
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I feel a little responsible for this line of conversation... I kinda started it all with that reference to the "corporations will rule the world" bit. That's an actual argument I got once, and while it's already been satisfactorily answered, that answer opened up this can of worms, so I'll start my answering here.
I was only half-joking when I said companies will rule the world. Naturally, I don't believe they will actually be able to rule people the way governments do, but they will have a large amount of influence over world affairs. They already do, and I don't see any reason why that would change under an anarcho-capitalistic society. Possibly extremely large companies that depend on the government will be forced to collapse or break up, but smaller companies will flourish and grow thanks to the lower barriers to entry. In any case, I don't believe it's a bad thing that companies will be extremely influential in such a society. Since companies are trying to make money from their customers and investors, they have a better incentive to efficiently provide what the people want and need than any system of government. Ultimately, the free market will force unwanted and inefficient and otherwise "evil" companies out of business, so for the most part we won't have to worry about that. |
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Look at where the whole network was only 100 GHASH more than 100 thousand blocks already were already mined in Jan/11 http://blockchain.info/block-height/103000 look how difficult? 18,437.64 5 million relatively easy bitcoins Which at the time were worth something on the order of a penny apiece, due to the fact that Bitcoin was an unproven system that very few people were using and were afraid to invest large amounts of real money in. Nobody at the time seriously thought (although they all hoped) that bitcoins would be worth anything near what they are today. The only reason bitcoins are worth what they are today is because these early adopters were prepared to take the risk of expending a large amount of effort into something that may well have turned out to be a complete failure. All investments are like this. Those who take the risks stand to reap the rewards, and they also stand to lose everything if it doesn't work out. |
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10 million is a massive amount to have already been mined... thats like $70,000,000  The first bitcoins were mined by people investing their time and computer resources in a system which at the time was highly experimental and nobody really knew whether it was going to work or not. They took the risk, a huge risk in fact, and they deserve to see a return on their investment. They've earned every cent of it. |
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The domain is registered to:
Andriy Bilous
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Barcelona 08013 ES
Phone: +34 656275110
Email: andrey AT andrinalina.com
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