30

this is a generic answer applying to "light" wallets - I don't know much about the blockchain.info-wallet There are several approaches that may work. I'm not sure which methods are most easily available for a user of a blockchain.info-wallet, but probably #0a and #2, followed by #3, #0b and #1b. 0) Wait it out. 0a) Wait for the transaction to go through. ...


20

Answer shamelessly stolen from stackexchange: Difficulty encoding is thoroughly described here. Hexadecimal representation like 0x182815ee consists of two parts: 0x18 -- number of bytes in a target 0x2815ee -- target prefix This means that valid hash should be less than 0x2815ee000000000000000000000000000000000000000000 (it is ...


14

Yes, blockchain.info has its own testnet service: https://testnet.blockchain.info/


13

All parts directly involved with the wallet service are open source. On the github project page the repositories My-Wallet, My-Wallet-Integrity-Checker and MyWallet-RPC-Communicator is BSD licensed. The repositories My-Wallet-iPhone, My-Wallet-Android are GPLv3. However the database backend and some other parts of the site are not open source. This will ...


12

Cancelling unconfirmed transactions is easy. Just submit a higher fee double-spend transaction. For example: if you send a 0-fee transaction it could take a day before 1 block mines it. Then you send another transaction with the same inputs that just sends the money back to yourself. On this transaction you put a higher fee. This becomes more ...


12

It seems obvious to me that this is a scam. No legitimate investment in the world can guarantee a rate of return of 20 percent per day. At that rate, with a 5 btc initial investment, you'd own all the bitcoins in existence after 81 days. And after 15 months, you'd have this much. But you may want to contact blockchain.info directly; there is a contact link ...


11

Messages are stored in a database at blockchain.info (so that text should probably be changed). For a while it did use the blockchain for storing messages but this was changed after concerns from a few of the core developers. Concerns were expressed by Matt Corallo here Oh god, thats awful...that is quite possibly the worst way to implement messages in ...


11

To download the blockchain with maximal speed you want to be connected to nodes with high bandwidth. On default bitcoin will search and connect to random nodes. One can add nodes to bitcoin conf to tell bitcoin to connect to specific nodes. To add a node to the bitcoin client to connect to, add the following to the bitcoin.conf file in: Windows:/appdata/...


10

Look at a list of Litecoin web wallets to see if any one them sound familiar to you: LiteVault - Online Litecoin Wallet; private keys encrypted locally Hive Web Wallet - Online BTC/LTC wallet; private keys encrypted locally Liteaddress.org - Litecoin address generation tools (BIP38) Reddit LiteTip Bot - Give and receive Litecoin tips from reddit users ...


9

I can't elaborate much on your answer but can provide reasons as to why this market seems so bare. Apple has shut down other providers of BitCoin wallets for "legal reasons" -- all due to the legal ambiguity of BTC transactions. Your best bet is to look into mobile-optimized websites that offer BTC transactions. I'm unfortunately not too knowledgable on ...


9

Obviously, he is a scammer trying hard to look similar as the Blockchain's Official Investment scheme but there isn't anything like this ever before. Many scammers are there, one of the most luring advert is 'Earn through Bitcoin Mining from Antminer(S9)'. In the name of Antminer(S9) many persons reaching out through various social platforms to you and ...


9

You can't include the USD amount, but you certainly can include the btc amount in the QR code. The QR code essentially embeds a text like this: bitcoin:1ArmoryXcfq7TnCSuZa9fQjRYwJ4bkRKfv?amount=0.005 Note the amount here is the amount in BTC. You can generate a QR code for that text using gobitcoin.io. If you just want to insert an image, you can use ...


9

If you look at the output script for that output, you can see it looks like this: RETURN PUSHDATA(32) [some garbage] This script, beginning with OP_RETURN, is called a null-data output, and is used to store arbitrary data in the blockchain. These outputs can never be spent, there is no way to make the script ever evaluate to true. Because of this, they ...


8

It is possible, but it is also quite easy to hide your activity from such inquiries. For example, lets check Address 15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC: http://blockchain.info/address-relayed-ips/15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC We can see that most often it appears in the USA, with a dominant IP being 69.164.218.197 . If we check that IP with another ...


8

I wrote a small Python script which can be used to decrypt your encrypted MyWallet. It does the same as the MyWallet JavaScript, only in Python. Edit: the code below seems to be outdated, here's a working version as of May 2012. Copy the following into a file, make it executable, then run it: #!/usr/bin/env python import base64, hashlib, hmac, json, sys, ...


8

Public notes are simply attached to addresses/transactions in the blockchain.info database, not in the blockchain itself, it's more of a convenience service offered by this particular website than a protocol feature. And yes, you can make them on blockchain.info, you apparently do not need to own an address to tag it (some of my addresses got tagged without ...


8

You cannot. That feature has been was "temporarily" cancelled due to numerous reports of stuck transactions and growing awareness of its privacy limitations: https://blog.blockchain.com/2014/03/17/shared-coin-suspended-temporarily/ http://www.coindesk.com/blockchains-sharedcoin-users-can-identified-says-security-expert/ I dont think the previous version ...


8

However this is JSON, I imagine I can't use it to verify the nonce. You can. You can build the block header using the data at the beginning of the JSON object and then hash that. Of course it would be easier to get the block hex, which you can get by going to the block hash on blockchain.info and appending ?format=hex to the url. For example, for the block ...


7

You're correct; the expected confirmation time from any given point in time is always around 10 minutes (it may be a little more or less when the network hash rate has changed since the last difficulty adjustment). This question looked at that exact issue. Note that a retailer (or other transaction acceptor) doesn't necessarily need to wait for a block to ...


7

As mentioned in Daniel's comment, if you are trying to connect to the Bitcoin-client that gathers the information for the Blockchain.info site this is not trivial as the IP does not match the one of the website. If you are just interested in adding the same nodes the site is connected to, that's no problem. With Linux or OS X you'd do something like this: ...


7

For transactions with one input it is hard to guess what is the change and what is the real payment. However because they may be have statistics so they can may be guess that for a ~4 BTC input there are 70% of probability that the change is the bigger output and the money spent the smaller one when both output addresses are new. Now if you have a ...


7

Click "Show scripts and coinbase" to see what that output really is. In this case it's RETURN PUSHDATA(32)[8013...] RETURN (or OP_RETURN) causes the output to be unspendable. The PUSHDATA then is just a way to insert the 32 bytes 8013... into the blockchain. The significance of that data is not necessarily known to anyone except the person who created the ...


6

Use pywallet to extract the private keys and copy the output to blockchain.info's Import Backup page. To use pywallet, you open a command prompt/terminal window at the folder where you saved it and type ./pywallet --dumpwallet --password="Whatever your passphrase is". NOTE: this will output everything in plain text, so if you do this on a public computer or ...


6

www.blocktrail.com/tBTC now supports testnet too and has an API for it too (including wallet API)


6

If a transaction returned from the http://blockchain.info/rawtx/$tx_hash endpoint has a confirmation, it will have a block_height member. You can then calculate roughly its number of confirmations by subtracting that value from the latest height retrieved from the http://blockchain.info/latestblock endpoint. Code example, in Ruby: #!/usr/bin/env ruby ...


6

My Wallet's warning for watch-only addresses ("You will not be able to send bitcoins from this address without later providing the private key") can be a bit confusing. It's possible to specify an address and watch it. And it's possible to import a private key to be able to use the associated address as if it was generated with the My Wallet client. But ...


6

Okay, so after investigating the provided restore tool (thanks Lohoris for pointing it out!), I arrived at the following answers to my questions: The input key for the AES decryption is 32 bytes (256 bits) The block size used is 16 bytes (MCRYPT_RIJNDAEL_128 for PHP mcrypt functions) The initialization vector (IV) for the AES decryption is the first 16 ...


6

Network propagation is the number of nodes (computers running a bitcoin client) that have heard about your transaction. Confirmations is how many blocks have included your transaction and how many blocks have linked onto that block. 1 confirmation means your transaction was included in a block, 2 confirmations means that another block linked onto that ...


6

You can add the bitcoin address to the search field at blockchain.info and you should be able to track any incoming transactions to that address. https://blockchain.info/address/1BF8SHKnT8ZysYNrj5toeu6DsuGE5XDcCR


6

From the source code, one can see that the mnemonic in fact only encodes your password and wallet identifier. You would still need to access you wallet data somehow to recover you coins.


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