I think only for small payments the Bitpay doesn't require confirmation
But if fee >= 0.0001 BTC, it's not problem - as rule the payment will be confirmed quickly and for double spending an attacker should do a mining very quickly
But if fee is very small for this transaction it will be in pool very long time (am attacker without problem will set fee <0.1 mBTC).
Then an attacker can make a double spend and mine only block with new double spend transaction and he will have more time because first transaction will wait ~ days for confirmation.
Right?

The Bitpay accepted my payment after 2 seconds
And $3 there is in my account at the Namecheap

Transaction is here:

https://blockchain.info/tx/241a9cb0a9374d432e230ecbc8f88494856b38e201455d2faa5c0de8a90b3aa3

I paid 1 Satoshi for it.

I am very interested when this payment will be confirmed...

P.S. And only a notice: the Bitpay reuse addresses for orders. Here address of Bitpay for my order: https://blockchain.info/ru/address/18Gds8K6HUBcojEN2jj1kaA9rmxdwNzHV8
And now i think experiment is not enough clean - in my last transaction used input with 16 mBTC, so priority of transaction will be few more than first transaction where input was 8 mBTC

Thanks for replies.
Now i want to make some test for Bitpay
The namecheap uses Bitpay for payments. I will test now there what happens

Ooopss..
I see this transaction again but time of arriving there is new - today...

https://blockchain.info/tx/f0171af132cf728e162b561391f2019712b6c5400e702d0c232c897a34a85c27

May be this transaction will be confirmed through ... X days/months

Hi,

I experimented with my wallets and transfered to mine from other wallet 0.008 BTC with fee 0.000001 (1/100 from recommended). Inputs of this transaction refered to outputs of other transaction with only 1 confirmation. So weight of inputs were very low priority. And value of this transaction was < 0.01 BTC which recommended.

I saw my transaction in "memory pool" at blockchain.info. It had not be confirmed very very long time (i waited ~ 2 days) and now there is no this transaction at blockchain.info. I think it was ignored and wiped as dust by nodes. My wallet now thinks that this transaction is pending and doesn't allow to spent this money. Ok, i know if i restore wallet from private keys at other device may be i will be able to spent this money. My question not about this.

I know shops which accepted micropayments after 0 confirmations. I thought it's fine and ok because double spending is very difficult. But after this the case i don't think same.
An attaker can send a micropayment to same shops by way as i did. Shop sees transaction (value < 0.01 BTC) in pool and decides to release a good or a service to buyer. But after this the payment will stay in memory pool long time and after erased because some conditions occurred from default described here: https://en.bitcoin.it/wiki/Transaction_fees

What should shop do for to prevent such instances? Software of shop should see in transaction fee? But if the buyer did not do it intentionally (wallet had fee as 0.000001 BTC for example or there zero fee)? And if this happens, as a shop in advance, fast, can know - will this transaction confirmed (even after 1-2 days) or not?

I think i understood why Merkle tree was made by Satoshi

Yes, when client software loads/checks the blockchain it can find spent/unspent transactions. The data of these transactions can be needed only for checking a transaction chain to genesis block. So client software starts to check from output tips of every transaction from upper block to down, and bodies (payloads) of most old transactions can be eliminated from local blockchain data at disk but we have a hashed Merkle root in every header block and we can check is there transaction id in same block or not. Because unspent (and spent) transactions has inputs as transaction id + output index I think this info will be enough to trust because transaction id checked by miners and approved by them by hashing block header with Merkle root. But after compressing same method as i understood we cannot to make fully checking again because we will not have payload (array of inputs [ txid, output_index ] ) of oldest eliminated trafnsactions we will have only info - "is there tx or not in such block".

So in future the Bitcoin Core can compress the local blockchain and eliminate all old spent transactions.

Right?

My mistake about pruning (from Satoshi's paper):


So if i understood right now the Bitcoin Core even now could have a feature don't keep spent transactions?
That is, when it loads blockchain it can find spent transactions and eliminate theirs and keep only Merkle tree?

Ok, i see

But please other question, please read:

https://en.bitcoin.it/wiki/Scalability#Storage

I have read Satoshi's paper and there pruning to be used for Merkle tree. Merkle tree to be needed only for quickly searching and checking "Is there transaction in block or not". I think there is error in wiki that Satoshi described pruning as "way to delete unnecessary data about transactions that are fully spent"

Ok, i understood you. May be this will be dangerous but this "compressed block" should be checked by miners and to be accepted by network. In first time full nodes will have a whole blockchain data in start time. Then if compressed block checked by other nodes and is approved by finding a nounce for the target hash this block can be basis for unspent transactions. After this through some time (for example after 100 confirmations) full nodes can forget about olddest blocks. If attacker will want to rewrite history he to be needed to make same job as to generate 100 confirmation for example. I think it will be hard to do as well as to rewrite blockchain from this place.

Now we have two protocol: full node and simplified protocol. I suggest to improve full node protocol.

Maybe I am much mistaken for these "compressed blocks"

But if the Bitcoin will be very popular and there will be ~ 2000 tps (https://en.bitcoin.it/wiki/Scalability#Network) then full nodes as it to be today should have: 2000 * 512 * 86400 = 82G per day (30 TB per year). And there (in blockchain) will be 90% of spent transactions. Now the Bitcoin Core should to be runned whole day from bootstrap file. What will be through 2-4 years?

Hi all,

Sorry for my English if it's not good for understanding

I am ordinary user if Bitcoin. I am concerned about the increasing size of blockchain. Now in the Bitcoin not so much amount of tansactions but if the Bitcoin will be bery popular the Bitcoin blockchain will be unreal biggest for ordinary users and for using.

I want to suggest an approximate solution fot decrease blockchain of Bitcoin.

As i think now the blockchain to be need for checking all not spent outputs of transactions. Some not spent outputs deeply submerged under blocks. Some transactions with unspent outputs can be in the block number 123, other in the block number 128523 and so on. By this reason a client software needs scan and check all blockchain from up to down for balances of client's addresses and so on. I want to suggest simply solution. Details are skipped. This is a very rough description, sorry for it

I think the blockchain can have a special block to be mined and to be checked by miners (difficulty can be more strong and to be based from current difficulty). This block can be mined through 2016 blocks for example (every two weeks) as the difficulty to be changed. This will be special block without current live transactions. It will have only transactions with unspent outputs. For example i will call this block "the compressed block". This block should have only unspent outputs of transactions to be happened from previously "the compressed block". Because now the blockchain doesn't have same blocks first block should have all last unspent transactions from genesis block for example. Same special blocks should be checked by miners (miners will have whole blockchain in first time) and to be mined by same algorithms as normal blocks with transactions. I don't know how to use there coinbase. May be the reward for this block same as normal and reward will be devided to two after 210,000 blocks but these blocks take into account in total mined blocks.

When same "compressed blocks" will be there client software can download blockchain from up plain blocks down to first compressed blocks then it can load only old compressed blocks. I think now that this information about unspent transactions could be enough for the normal functioning of the network. But these blocks will resolve main future problem of biggest size of blockchain in future. All made transactions will be eliminated from memory of clients and client's blockains.

What do you think about this?

Done!

F*ck, after restart and started Armory again i see now sign transaction dialog.
I don't understand this beta version...
It's very buggy. Some dialogs work same: click -> nothing -> click -> ok -> click -> nothing -> click -> nothing -> click -> OK -> click -> OK
It remains me a mining

Please HELP needed!

I created offline wallet in Ubuntu (Armory Offline, 0.91.99) and exported only watch-only wallet to Windows computer where run Armory 0.91.99.8-beta
Windows version synced fully completed, i sent some bitcoins to addresses, i see theirs in balance (1 confirmation), the wallet has "Belongs to" as "You own this wallet"
BUT!

I cannot make offline transaction!
I do: "Send bitcoins" (Windows) -> Enter my other recipient address, amount (here other bug  too - to see below) and i after i click button "Continue"
And nothing happens!
Finish...
I cannot how can i made transaction to USB flesh...

Other bug in this window where i try to send bitcoins: when i click "MAX" button sometime i got error message: "Cannot compute the maximum amount because there is an error in the amount for recipient 1". I close this error modal window, click "MAX" again and amount field to be filled and nothing error again. If i try to reproduce bugi can see this error again and again...

P.S. May be it's normal behaviour of Armory, i don't know. I have now funds which have only 1 confirmation. May be Armory waits 6 confirmations? If yes, it's very strange - MAX button fills to me sum of all balances (1 confirmations) but Continue doesn't work and nothing there warnings and etc... Many clients allow to send bitcoins after 1 confirmation.

P.P.S. "Wallet Properties" window shows to me "Spendable Funds" > 0 BTC. But "Continue" button doesn't work right now. If i keep empty field of address and press "Continue", i got error that address is not valid. If i fill valid address but amount is empty, "Continue" button tells to me that amount is not specified. If i specify "Amount" and i press "Continue" - nothing happens...

Из вас тут программисты есть?

Вот, почитайте
http://btcsec.com/ethereum/

Я почитал... Такого бреда я с роду невидал. Да это IPSUM # 2.


Какой любой язык программирования? Си, Perl? Код, передающийся через blockchain? А память, стек, регистры? Сетевая поддержка TCP/IP? I/O на диск, вирусы и прочее.


О чём автор вообще? Какое дописанное приложение, которое уже устарело? Полно разработчиков пишут под Android, iOs, Linux Windows. Всех всё устраивает и все всё успевают дописывать.
А термины, которые здравомыслящий программер даже не слышал - "Тьюринг-полные контракты на базе блокчейна"...

Или вот это:


С кем договор? С блокчейном? Или с тем, у кого есть публичный адрес? Через что снять? Через карточку в банке? В банке тоже Ethereum запустят для этого, или Visa & Mastercard?

Люди, да это полной воды гон, пыль в глаза. Это развод в стиле Ipsum и саентологической церкви. Когда начинаешь читать и вдумываться, крыша едет от нелогичности. Это чисто психологичнские приёмы жуликов - наговорить терминов, про которые вы не понимаете, удобрить их технологией, которая вам известна (Bitcoin), и вы, ничего не понимающие, переносите подсознательно заслугу Биткойна, которая действительно великолепна, на некий непонятный виртуальный продукт со сказочными характеристиками, которые, кстати, никому не нужны. Кому то и вправду нужно запустить DNS в блокчейне? Есть потребность? Или "А надо снимать не более в день"?

Я погуглил ещё про это и нашёл, что Ethereum хотели запустить в феврале 2014. Сейчас лето 2014. Продают то, чего нет. Теперь обещают зимой 2015. Также, погуглите "Ethereum scam"

Да всё что там написано, даже Гугл никогда не соберётся сделать, потому что всё что так хотят сделать - просто нелогично, ненужно и невостребовано. Живите лучше в обычной реальности и тратьте свои деньги лучше на благое дело. Например на donations разработчикам земных приложений.

А я, лично думаю, всё кончится тем, что парни будут тянуть резину, собирать бабло, а потом скажут "парни, у нас ничего не получилось. Проект был очень сложный. Не всё работает как надо. Мы запускать это передумали. Но мы вам ничего не вернём, так как вы же соглашались с нашими термсами "
А потом все будут искать этого Виталика с биткойнами впридачу

Тогда расскажите мне в кратце - что это? Для чего он? Только, плиз, говорите применительно к повседневной жизни. Я вот, например, уже Биткойн в банкомате снимал, платил в инет магазинах, платил за телефон и за интернет, кидал со своего мобильного Bitcoin Wallet на мобильный жене, за 5000 км. от меня, и она через 10-15 минут уже оплатила мобильник свой и пополнила карточку в банке.

И вот повилось это "чудо", чудо юдо, про которое никто толком сказать не может.
Что это? Зачем оно мне? Или моему соседу?

Я почитал даже на английском проект этого русского Виталика из Канады. И понял, что ничего не понял. Попытка сделать систему неких smart contracts, но что именно это - непонятно. Это система, заменящая форумы и доверительные отношения? Или возможность купить за деньги доверие кого то?

Почитал я этот Ethereum

Хрень какая то полная, если честно. Кажется, человеку, который любит биткойн, захотелось придумать что-нибудь, чтобы стать вторым Сатоши Накамото. Вот и придумал ерись - он явно насмотрелся Матрицы и ярый её поклонник. Все трубят о преимуществах, но ничё толком сами не знают. Только и заклинают "Smart contracts". Цветные монетки, у каждой своё имя. Пипец просто. Представляете, там 5 или шесть типов монет - просто если в биткойне mBTC, nBTC, то там это названо своим именем. Получается, чтобы пользоваться этим, надо как минимум запомнить пять имён, которые в русском то трудно произнести.

Биткойн был придуман в 2008 во время банковского кризиса. Сначала была потребность, потом появилась технология. Простая технология. Правда и то это непонятно людям, так как не вписывается в стереотипы людей ("как можно создать счёт принятия платежей в оффлайне?"). Тут же, как мне кажется, потребности особой нет, но появилось нечто сложное и непонятное и теперь к этому хотят прикрутить какие то выдуманные потребности. Добавили к этому маркетинг и вот теперь трубят, что "Появилось то, чего так долго ждали."

Кто ждал?

Распродали это гавно лохам за 3 млн. долларов. С чем их и поздравляю

One question please: data are collected in moment only when i press button "Create" or before?
I don't see any messages like "To move mouse, to press some keys" and don't understand where start and end time for real world  entropy?

Sorry, my mistake may be
I see now that multiplier is EC function.
I don't know how it works but now i think if anybody knows publicAddress(i+1) and publicAddress(i) he cannot find chaincode?

As i understand if anybody knows my "i+1" public address and "i" address he can easy calculate chaincode?
Yes?
And same chaincode used in for generation of next private key?
So if anybody will define (i don't how it's gypotetical question) private key i+100, and he knows "i+1" and "i" public keys (for example i am shop and one customer bought 2 orders: one order -> two order and after he knows my chaincode?) he will know next private key and so on?
May be here is some vulnarabilities?

Hi,

I use Ubuntu for offline (and for online too) computer because:

1) I buy very fine and low cost small ASUS computer (model X200ma, cost ~$240 without tax). This price for clean without OS computer
2) The cost of Ubuntu $0
3) It's fine and easy OS
4) In any time a can reformat whole computer (if i decide wipe all soft from where) and install new Ubuntu OS. Price $0. No activation and other shit from Windows
5) I can make an easy encryption of whole HDD disk with password during installtion process. It's super for offline computer if it will be stolen. And for online of course.
6) It fine works in all modes - sleeping, waking up and so on.
7) It understand all format of file systems: fat, vfat, fat32, ntfs, ext3 & ext4 in write modes and so on. It's fine for USB flashes
It's open OS so i think there no hidden bugs from NSA

Привет всем!

Сегодня купил и продал в банкомате типа Robocoin в Праге Биткойны
Кому интересно - можете почитать

http://blog.perlover.com/2014/07/21/bitcoin-%D0%B1%D0%B0%D0%BD%D0%BA%D0%BE%D0%BC%D0%B0%D1%82-%D0%B2-%D0%9F%D1%80%D0%B0%D0%B3%D0%B5-%D0%BB%D0%B8%D1%87%D0%BD%D1%8B%D0%B9-%D0%BE%D0%BF%D1%8B%D1%82/#.U8z_TLFCOUk