MultiBit – Secure Bitcoin Desktop Wallet For Storing ...

MultiBit HD now has a system baked in to pay to the developers automatically, a small amount, and " BRIT creates a distributed income stream that is centralised at the point of initial anonymous contact. This contact occurs when the application first starts" - what are the privacy implications?

MultiBit HD now has a system baked in to pay to the developers automatically, a small amount, and submitted by d-X-X-b to Bitcoin [link] [comments]

Is it possible to know which addresses contain non zero balance and their private keys by just using the seed words of the multibit hd wallet?

submitted by yegormintbikgaihain to BitcoinBeginners [link] [comments]

HODLer holding no more - This time it really looks different

Long time hodler here. Won't post my wallet address but click on the imgur link and you can see on the screenshot I took when I started hodling. Back when MultiBit wasn't even MultiBit HD and Peercoin was still a thing.
Alas, with the drop in price, this week I'm giving up on Bitcoin. Maybe not forever, but for an year or two, in case things change.
Here's my reasoning, I post it here in the hopes someone can prove me wrong. As they say on UFO, "I want to believe"
Reason #1 - This time adoption is actually falling
Back in the day, Microsoft started accepting BTC. Then Expedia, Steam... Now they are all bailing out. People will tell me about lightning, what brings us to...
Reason #2 - This time the tech is not going forward.
Don't get me wrong, I know that in theory (and even in testnet) Lightning seems to work perfectly but that's not where my bitcoins are. My bitcoins are on mainnet, a place where devolpment has stalled, objectively speaking. Segwit adoption hasn't even broken 50% and the most known wallets are not using it (BRD, which used to be called bread wallet, blockchain.info, etc.) and lightning is far more complex than segwit. The programming of watch towers alone for Christ sake, is more complex than implementing segwit 5 times over.
Reason #3 - There are no newbies left to be converted.
Back in 2013, even if the price fell 90%, it didn't matter much. Because most people hadn't heard about it. Now, everyone and their uncle are aware that bitcoin exists and that it went all the way up to $20,000 and now it's down to $6,500. It is far easier to convince someone who does not know anything about bitcoin to use it than it is to convince someone who lost 60% of what they invested in this "internet money" to come back and give it another chance. If you ever find yourself divorced, would you rather find a new girl or go back to your ex, whom you can't even think about without feeling a sour taste in your tongue?
Reason #4 - The competition will be hard to beat.
Back in 2012, you could tell your friends about this "magical" thing that was sending someone money over the internet, with the click of a button. Now we have apple pay and NFC. Even with Lightning, I find it hard to believe that bitcoin will ever be less cumbersome than the methods of payment we have now.
Reason #5 - Even if the price goes back up, the network is still broken.
I hate to side with Bcash supporters but the truth is Bitcoin "classic", BTC, is still now ready to be used by everybody. Even if, by some unkown reason, we get everyone we had in December '17 back and the price goes all the way up to $20,000, fees will be the same they were back then. It's still taboo to talk about a reasonable block size increase. Do you remember when it cost $20 to send a transaction? That's still the case if bitcoin gains adoption. I mean, we may get it down to $16 with batching and 37% of the wallets using Segwit but the problem is NOT solved and lightning as a fix is at least 5 years away.
Reason #6 - The speculation money is all on ICOs.
If we have no widespread adoption we have to rely on speculators to drive prices up. Back in 2013 we had them on board. Now they're gone, there is no easy money to be made in BTC. And there will never be a CryptoKitties that will make you rich overnight. Bitcoin is just too old to be a talented child that can join the Jackson Five and still to young to play with KISS. It's a teenager that is too embarassed to go to school with mom but too young to drive.
Reason #7 - We can't buy and can't mine anymore
In theory we can, of course. But I still remember 2013 when I bought one whole bitcoin every month, with what was left from my salary. Now I can't even buy 0,1 BTC with the same money. And I can't mine either. Back than if you didn't have any money you could get BTC that way. Now... It's too expensive to be bought and too cheap to be sold. Maybe that's why we call ourselves HODLERS. Holding is all one can do now.
Reason #8 - It's not "my club" anymore
From time to time I still check Satoshi's profile on bitcointalk.org. And Gavin Andresen's blog. And Mike Hearn's. Now they're gone. One can't help but feel old. I know this is not a logical reason to give up on bitcoin but still... I feel like the guy who's still trying to hook up with the cheerleader from high school while all of my friends have moved on...
I know it's an old cliché. But this time, it really looks different.
submitted by elverino to Bitcoin [link] [comments]

Help, I accidentally sent bitcoins to a wrong address :(

Hello everyone,
I messed up with my bitcoins and sent them to the wrong address but I don't know where the hell this address is from... According to the blockchain this address has only my transaction.
Here is the adress: 18VUDxb7vCs6zeVr6sy52byoNFK377JhYY
If you want to help me find out where this address comes from here is what I did:
I don't understand where the wrong adress comes from, I looked for this adress everywhere but can't find anything.
Please help me I'm so disapointed..
submitted by lbtc7471 to Bitcoin [link] [comments]

Probably silly to ask, but (what the heck) ...

Well, when I got started with bitcoin earlier this year, I got busy exploring the different wallets. I bought some bitcoins and moved them between wallets to see how the whole process worked, and also I wanted to understand how the different wallets worked. I ended up using MultiBit for the most part, but I also tried hot wallets, such as breadwallet, hive, coinjar, or online wallets, such as Circle, coinbase, and blockchain. I also ended up with several paper wallets for long time storage, which I however ended up unloading into a mytrezor just recently. As dumb as it might sound, but I somehow lost a transaction in the process. For some reason I believe I made a transaction, but I do not know to which wallet. I double checked all my wallets, but I do not know where I sent this transaction to. As that transaction contained 10.09 btc it seems to be a rather costly fuck up. So, my question is, is there any way to somehow find out, which service a certain public address belongs to? I am very convinced there is no way to do so, but what do I know.
I believe the transaction I am missing was the one sent to this address: 12VrVY8f13Tr2EAYSTYb4MQkqTg9uDoG4n
EDIT: Could be from one of the paper wallets I had. I depleted those wallets via blockchain by importing the private keys. Could not be that there were amounts left over on those paper wallets, could there?
EDIT2: BTW, thank you all for your constructive comments. I actually believed I would get mocked much more for my mistake. Would have deserved it, in any case.
Thanks for any ideas on this matter.
submitted by jaykayaway to Bitcoin [link] [comments]

Bounty: 1.5 Million DOGE for the first person to create an electrum equivalent for dogecoin.

Houston, we have a problem.
The current dogechain over 1.4gb in size. This is incredibly bloated.
As time goes on, the size of the blockchain will only continue to increase, making sync times longer. Long sync times are bad because they may scare off newcomers who may need to download for hours or days before using dogecoin.
For obvious reasons, this is very bad.
Bitcoin has solved this problem by creating electrum and multibit, which are wallets that stores the blockchain online, but the wallet data locally. This allows for very small wallet sizes, with all the security features of having a local wallet.
We must do the same thing.
We have therefore decided to offer millions of dogecoins for anyone that can create an electrum equivalent for dogecoin.
If any shibes wants to help increase the size of this bounty, please donate to DMxCwo7qJphRVeC6pHcoDHaizk55pg6iNt . This address will only ever be used for the pot. Please do not tip me directly, because I need to keep track of money meant for me vs. money meant for pot.
tl;dr: Wow. Downlod much difficult. Hueg fil. need fix 2 get 2 moon. Such payment 4 fix. Such gud 4 new shibe. Bark bark.
 . 
Current Pot Size: Zero. Bounty has been paid out. See this for history
Note: I only control a portion of the total size of the pot. The rest are by individuals who have promised to give directly.
Much Generous Shibes who have contributed to the Pot:
Tuxedage, [-wolong-] (1m, give directly), thatslifeon (0.5m, give directly). tohaz (0.5m, GD) Shibe_Tabsa @ Teamdoge. mljsimone @ Hashdogs, Keebler64 , McPingvin, TheDoctor , need4doge , ummjackson, Faxon, UltraHR, UnsureSherlock, cpt_merica
Please message me with your name and donation amount if you want to get on this list.
 . . 
IMPORTANT ANNOUNCEMENTS -- If you are working on this project, please check here for important updates every few days

1: I see a lot of people tipping. I've already said this once, but I'll say it again. Please don't tip if your intention is to add to the pot. Send directly. I bear no responsibility if your funds are misplaced or accidentally lost.

2: I am now aware that an android wallet exists. Although I thought it was obvious from context, let me reaffirm this: I would like a wallet that works on Windows/Mac/Linux, and has an easy to use installer, rather than necessitating some kind of android emulator to port it over to a computer. It must be newbie friendly.

#3: Langer_hans has brought up a valid point -- the current phrasing of the thread is dangerous because it encourages bad, but quick submissions, as only the "first person" gets the bounty. I am proposing changing the system; users will vote on which wallet they like best. The one with the most votes will get the bounty instead. This should encourage people to actually make good quality submissions, and also to collaborate. What do you guys think?

4: 15th of February is the final deadline for wallet entree submissions. Please message me with FULL DETAILS (including name, download information, website, user guide, other info, and so on) of your wallet to submit. Users will then get 1 week to try out different wallets and form an opinion of them. A week later, I will open up a poll for voting on which wallet is the best. Whichever wallet gets the most votes will obtain the prizepool. About 400k of the pot will be reserved for consolidation prizes, to be distributed at discretion. (So that shibes who didn't win won't feel sad).

*#5: Due to exogenous circumstances, competition will start on the 19th Feb as opposed to 15th. Sorry for the delay. *
** #6: VOTING IS OPEN. http://www.reddit.com/dogecoin/comments/1yhf5c/the_dogecoin_lite_wallets_are_complete_vote_now/ **
If you need to contact me urgently, please go to the dogecoin IRC -- #dogecoin @ irc.freenode.net and message me.
 . 
List of Submissions
If you do not see your name or entree on here within 48 hours of messaging me, please message me again until I add it.
Final Update:
Given the incredibly close results of the poll, the Developers and I have privately discussed how best to distribute the bounty. They have mutually agreed to a 50-50 split. The bounty has been paid out. Cheers.
People who have pledged to directly donate to the developers, please message me. Thank you
submitted by Tuxedage to dogecoin [link] [comments]

My first Bitcoin transaction shows up as confirmed, but after two hours I still haven't received anything

Hi everyone! Very very new to Bitcoin - I bought my first 0.12 Bitcoin today (woo!). I did it via bitbargain.co.uk and immediately sent it to my wallet, but after two hours it still hasn't turned up. I've checked my address ( 12R5rgkGc7LutFYVRMWKz3kRWLTL44jFwH ) using biteasy.com to see if the transaction was confirmed, and as far as I can tell it is. Have I somehow messed up my first transaction? Thanks in advance!
submitted by verynewtobitcoin to BitcoinBeginners [link] [comments]

Poloniex threatens to freeze my account because I wasn't 'trading' on their platform.

Dear XXX,
submitted by RiptideHunter to ethtrader [link] [comments]

Please help me, I have lost access to my wallet

Okay So I have Multibit 0.4.23 installed, and have about 30 odd bitcoins which represent my life savings. I opened up my MultiBit today (after not having accessed it for about a week), and it download hundreds of blocks to be up to date. My wallets are not appearing in the left hand panel, and I am FREAKING OUT.
I made a backup of the .key and I also have time machine which last updated a few weeks ago. What can I do?
submitted by FAT_LOUD_HOUND to Bitcoin [link] [comments]

I bought some bitcoins on bitbargain (UK) 6 days ago and their still not 'Available to Spend' in MultiBit?

It was my first purchase buying bitcoins, and I only bought £10 worth just to test it, but it's been 6 days and it still says they're not available to spend. Should I just wait longer or get in touch with the seller or what?
submitted by astro-slut to Bitcoin [link] [comments]

PSA: Clearing up some misconceptions about full nodes

It's time to clear up some misconceptions floating around about full nodes.
Myth: There are only about 5500 full nodes worldwide
This number comes from this site and it measured by trying to probe every nodes on their open ports.
Problem is, not all nodes actually have open ports that can be probed. Either because they are behind firewalls or because their users have configured them to not listen for connections.
Nobody knows how many full nodes there are, since many people don't know how to forward ports behind a firewall, and bandwidth can be costly, its quite likely that the number of nodes with closed ports is at least another several thousand.
Nodes with open ports are able to upload blocks to new full nodes. In all other ways they are the same as nodes with closed ports. But because open-port-nodes can be measured and closed-port-nodes cannot, some members of the bitcoin community have been mistaken into believing that open-port-nodes are that matters.
Myth: This number of nodes matters and/or is too low.
Nodes with open ports are useful to the bitcoin network because they help bootstrap new nodes by uploading historical blocks, they are a measure of bandwidth capacity. Right now there is no shortage of bandwidth capacity, and if there was it could be easily added by renting cloud servers.
The problem is not bandwidth or connections, but trust, security and privacy. Let me explain.
Full nodes are able to check that all of bitcoin's rules are being followed. Rules like following the inflation schedule, no double spending, no spending of coins that don't belong to the holder of the private key and all the other rules required to make bitcoin work (e.g. difficulty)
Full nodes are what make bitcoin trustless. No longer do you have to trust a financial institution like a bank or paypal, you can simply run software on your own computer. To put simply, the only node that matters is the one you use
Myth: There is no incentive to run nodes, the network relies on altruism
It is very much in the individual bitcoin's users rational self interest to run a full node and use it as their wallet.
Using a full node as your wallet is the only way to know for sure that none of bitcoin's rules have been broken. Rules like no coins were spent not belonging to the owner, that no coins were spent twice, that no inflation happens outside of the schedule and that all the rules needed to make the system work are followed (e.g. difficulty.) All other kinds of wallet involve trusting a third party server.
All these checks done by full nodes also increase the security. There are many attacks possible against lightweight wallets that do not affect full node wallets.
This is not just mindless paranoia, there have been real world examples where full node users were unaffected by turmoil in the rest of the bitcoin ecosystem. The 4th July 2015 accidental chain fork effected many kinds of wallets. Here is the wiki page on this event https://en.bitcoin.it/wiki/July_2015_chain_forks#Wallet_Advice
Notice how updated node software was completely unaffected by the fork. All other wallets required either extra confirmations or checking that the third-party institution was running the correct version.
Full nodes wallets are also currently the most private way to use Bitcoin, with nobody else learning which bitcoin addresses belong to you. All other lightweight wallets leak information about which addresses are yours because they must query third-party servers. The Electrum servers will know which addresses belong to you and can link them together. Despite bloom filtering, lightweight wallets based on BitcoinJ do not provide much privacy against nodes who connected directly to the wallet or wiretappers.
For many use cases, such privacy may not be required. But an important reason to run a full node and use it as a wallet is to get the full privacy benefits.
Myth: I can just set up a node on a cloud server instance and leave it
To get the benefits of running a full node, you must use it as your wallet, preferably on hardware you control.
Most people who do this do not use a full node as their wallet. Unfortunately because Bitcoin has a similar name to Bittorrent, some people believe that upload capacity is the most important thing for a healthy network. As I've explained above: bandwidth and connections are not a problem today, trust, security and privacy are.
Myth: Running a full node is not recommended, most people should use a lightweight client
This was common advice in 2012, but since then the full node software has vastly improved in terms of user experience.
If you cannot spare the disk space to store the blockchain, you can enable pruning. In Bitcoin Core 0.12, pruning being enabled will leave the wallet enabled. Altogether this should require less than 900MB of hard disk space.
If you cannot spare the bandwidth to upload blocks to other nodes, there are number of options to reduce or eliminate the bandwidth requirement. These include limiting connections, bandwidth targetting and disabling listening. Bitcoin Core 0.12 has the new option -blocksonly, where the node will not download unconfirmed transaction and only download new blocks. This more than halves the bandwidth usage at the expense of not seeing unconfirmed transactions.
Synchronizing the blockchain for a new node has improved since 2012 too. Features like headers-first and libsecp256k1 have greatly improved the initial synchronization time.
It can be further improved by setting -dbcache=3000 which keeps more of the UTXO set in memory. It reduces the amount of time reading from disk and therefore speeds up synchronization. Tests showed that the entire blockchain can now be synchronized in less than 3 and a half hours (Note that you'll need Bitcoin Core 0.12 or later to get all these efficiency improvements) Another example with 2h 25m
How to run a full node as your wallet.
I think every moderate user of bitcoin would benefit by running a full node and using it as their wallet. There are several ways to do this.
So what are you waiting for? The benefits are many, the downsides are not that bad. The more people do this, the more robust and healthy the bitcoin ecosystem is.
Further reading: http://www.truthcoin.info/blog/measuring-decentralization/
submitted by belcher_ to Bitcoin [link] [comments]

VERY IMPORTANT - Need help with a BTC transaction

SOLVED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Thanks to therockmortonsign and gimpycpu.
Hi, I am using Bitcoin since 2013, never had a problem, one of my relative bought 1 BTC in 2013, the Bitcoin was stored in MultiBit 0.5.15.
My relative wanted me to sell the Bitcoin, so I just made a transfer. I had to send it to my blockchain address. Here is the proof of my reception adress: http://img11.hostingpics.net/pics/161809BTC01.png
I sent the 1 BTC to the reception address, the transaction was confirmed here is the proof: http://img11.hostingpics.net/pics/202915BTC02.png
I thought it was a bit strange because If I remember well, I had a password to the wallet, but they didn't ask me the password and I got the confirmation. Then I started waiting, and waiting, and after 1-hour with no confirmation, I started panicking a little bit.
Normally I would patiently wait, but now I am extremely worried. I tried to check the transaction on the blockchain but the transaction could not be found.
Here is the picture of the transaction: http://img11.hostingpics.net/pics/157955BTC03.png
Now here is the link for the transaction
https://blockchain.info/tx-index/9e1dfd408bdcaec823d894c740bbbac947cf174741bfa394410a19a2c51dbc71
https://blockexplorer.com/tx/9e1dfd408bdcaec823d894c740bbbac947cf174741bfa394410a19a2c51dbc71
The transaction could not be found.... I am extremely worried right now, what the hell happened guys? Am I incredibly noob and freaking out for nothiing?!?!
I would like to know what I can do, knowing Bitcoin, I think I just lost his $1200CAD which put me in a lot of trouble, but I did absolutely nothing wrong in my opinion.
submitted by Brookefinancial to Bitcoin [link] [comments]

Secure paper wallet tutorial

This is my handout for paranoid people who want a way to store bitcoin safely. It requires a little work, but this is the method I use because it should be resistant to risks associated with:
  1. Bad random number generators
  2. Malicious or flawed software
  3. Hacked computers
If you want a method that is less secure but easier, skip to the bottom of this post.
The Secure Method
  1. Download bitaddress.org. (Try going to the website and pressing "ctrl+s")
  2. Put the bitaddress.org file on a computer with an operating system that has not interacted with the internet much or at all. The computer should not be hooked up to the internet when you do this. You could put the bitaddress file on a USB stick, and then turn off your computer, unplug the internet, and boot it up using a boot-from-CD copy of linux (Ubuntu or Mint for example). This prevents any mal-ware you may have accumulated from running and capturing your keystrokes. I use an old android smart phone that I have done a factory reset on. It has no sim-card and does not have the password to my home wifi. Also the phone wifi is turned off. If you are using a fresh operating system, and do not have a connection to the internet, then your private key will probably not escape the computer.
  3. Roll a die 62 times and write down the sequence of numbers. This gives you 2160 possible outcomes, which is the maximum that Bitcoin supports.
  4. Run bitaddress.org from your offline computer. Input the sequence of numbers from the die rolls into the "Brain Wallet" tab. By providing your own source of randomness, you do not have to worry that the random number generator used by your computer is too weak. I'm looking at you, NSA ಠ_ಠ
  5. Brain Wallet tab creates a private key and address.
  6. Write down the address and private key by hand or print them on a dumb printer. (Dumb printer means not the one at your office with the hard drive. Maybe not the 4 in 1 printer that scans and faxes and makes waffles.) If you hand copy them you may want to hand copy more than one format. (WIF and HEX). If you are crazy and are storing your life savings in Bitcoin, and you hand copy the private key, do a double-check by typing the private key back into the tool on the "Wallet Details" tab and confirm that it recreates the same public address.
  7. Load your paper wallet by sending your bitcoin to the public address. You can do this as many times as you like.
  8. You can view the current balance of your paper wallet by typing the public address into the search box at blockchain.info
  9. If you are using an old cell phone or tablet do a factory reset when you are finished so that the memory of the private keys is destroyed. If you are using a computer with a boot-from-CD copy of linux, I think you can just power down the computer and the private keys will be gone. (Maybe someone can confirm for me that the private keys would not be able to be cached by bitaddress?)
  10. To spend your paper wallet, you will need to either create an offline transaction, or import the private key into a hot wallet. Creating an offline transaction is dangerous if you don't know what you are doing. Importing to a client side wallet like Bitcoin-Qt, Electrum, MultiBit or Armory is a good idea. You can also import to an online wallet such as Blockchain.info or Coinbase.
Trusting bitaddress.org
The only thing you need bitaddress.org to do is to honestly convert the brainwallet passphrase into the corresponding private key and address. You can verify that it is doing this honestly by running several test passphrases through the copy of bitaddress that you plan on using, and several other brainwallet generators. For example, you could use the online version of bitaddress, and brainwallet and safepaperwallet and bitcoinpaperwallet. If you are fancy with the linux command line, you can also try "echo -n my_die_rolls | sha256sum". The linux operating system should reply with the same private key that bitaddress makes. This protects you from a malicious paper wallet generator.
Trusting your copy of bitaddress.org
Bitaddress publishes the sha1 hash of the bitaddress.org website at this location:
https://www.bitaddress.org/pgpsignedmsg.txt
The message is signed by the creator, pointbiz. I found his PGP fingerprint here:
https://github.com/pointbiz/bitaddress.org/issues/18
"527B 5C82 B1F6 B2DB 72A0 ECBF 8749 7B91 6397 4F5A"
With this fingerprint, you can authenticate the signed message, which gives you the hash of the current bitaddress.org file. Then you can hash your copy of the file and authenticate the file.
I do not have a way to authenticate the fingerprint itself, sorry. According to the website I linked to, git has cryptographic traceability that would enable a person to do some research and authenticate the fingerprint. If you want to go that far, knock yourself out. I think that the techniques described in this document do not really rely on bitaddress being un-corrupt. Anyway, how do we know pointbiz is a good guy? ;-)
There are a lot of skilled eyes watching bitaddress.org and the signed sha1 hash. To gain the most benefit from all of those eyes, it's probably worthwhile to check your copy by hashing it and comparing to the published hash.
"But we aren't supposed to use brainwallets"
You are not supposed to use brainwallets that have predictable passphrases. People think they are pretty clever about how they pick their passphrases, but a lot of bitcoins have been stolen because people tend to come up with similar ideas. If you let dice generate the passphrase, then it is totally random, and you just need to make sure to roll enough times.
How to avoid spending your life rolling dice
When I first started doing this, I rolled a die 62 times for each private key. This is not necessary. You can simply roll the die 62 times and keep the sequence of 62 numbers as a "seed". The first paper address you create would use "my die rolls-1" as the passphrase, the second would be "my die rolls-2" and so on. This is safe because SHA256 prevents any computable relationship between the resulting private key family.
Of course this has a certain bad security scenario -- if anyone obtains the seed they can reconstruct all of your paper wallets. So this is not for everyone! On the other hand, it also means that if you happen to lose one of your paper wallets, you could reconstruct it so long as you still had the seed.
One way to reduce this risk is to add an easy to remember password like this: "my die rolls-password-1".
If you prefer, you can use a technique called diceware to convert your die rolls to words that still contain the same quantity of entropy, but which could be easier to work with. I don't use diceware because it's another piece of software that I have to trust, and I'm just copy/pasting my high entropy seed, so I don't care about how ugly it is.
Why not input the dice as a Base 6 private key on the Wallet Details tab?
Two reasons. First of all, this option requires that you roll the die 99 times, but you do not get meaningful additional protection by rolling more than 62 times. Why roll more times if you don't have to? Second, I use the "high entropy seed" method to generate multiple private keys from the same die rolls. Using the Base 6 option would require rolling 99 times for every private key.
I'm a big nerd with exotic dice. How many times to roll?
Put this formula in Excel to get the number of times to roll: "=160*LOG(2,f)" where f = number of faces on the die. For example, you would roll a d16 40 times. By the way, somewhat unbelievably casino dice are more fair than ordinary dice
The "Change address" problem:
You should understand change addresses because some people have accidentally lost money by not understanding it.
Imagine your paper wallet is a 10 dollar bill. You use it to buy a candy bar. To do this you give the cashier the entire 10 dollar bill. They keep 1 dollar and give you 9 dollars back as change.
With Bitcoin, you have to explicitly say that you want 9 dollars back, and you have to provide an address where it should go to. If you just hand over the 10 dollar bill, and don't say you want 9 dollars back, then the miner who processes the transaction gives 1 dollar to the store and keeps the remainder themselves.
Wallet software like Bitcoin-Qt handles this automatically for you. They automatically make "change addresses" and they automatically construct transactions that make the change go to the change address.
There are three ways I know of that the change problem can bite you:
  1. You generate a raw transaction by hand, and screw up. If you are generating a transaction "by hand" with a raw transaction editor, you need to be extra careful that your outputs add up to the same number as your inputs. Otherwise, the very lucky miner who puts your transaction in a block will keep the difference.
  2. You import a paper wallet into a wallet software and spend part of it, and then think that the change is in the paper wallet. The change is not in the paper wallet. It is in a change address that the wallet software generated. That means that if you lose your wallet.dat file you will lose all the change. The paper wallet is empty.
  3. You import a paper wallet into a wallet software and spend part of it, and then think that the change is in the change address that the wallet software generated. If the transaction did not need to consume all of the "outputs" used to fund the paper wallet, then there could be some unspent outputs still located at the address of the paper wallet. If you destroyed the paper wallet, and destroyed the copy of the private key imported to the wallet software, then you could not access this money. (E.g. if you restored the software wallet from its seed, thinking all of the money was moved to the wallet-generated change addresses.)
For more on this, see here
The hot paper wallet problem
Your bitcoin in your paper wallet are secure, so long as the piece of paper is secure, until you go to spend it. When you spend it, you put the private key onto a computer that is connected to the internet. At this point you must regard your paper wallet address as hot because the computer you used may have been compromised. It now provides much less protection against theft of your coins. If you need the level of protection that a cold paper wallet provides, you need to create a new one and send your coins to it.
Destroying your paper wallet address
Do not destroy the only copy of a private key without verifying that there is no money at that address. Your client may have sent change to your paper wallet address without you realizing it. Your client may have not consumed all of the unspent outputs available at the paper wallet address. You can go to blockchain.info and type the public address into the search window to see the current balance. I don't bother destroying my used/empty paper wallet addresses. I just file them away.
Encrypting your private key
BIP 0038 describes a standardized way to encrypt your paper wallet private key. A normal paper wallet is vulnerable because if anyone sees the private key they can take the coins. The BIP38 protocol is even resistant to brute force attacks because it uses a memory intensive encryption algorithm called scrypt. If you want to encrypt your wallets using BIP38, I recommend that you use bitcoinpaperwallet because they will let you type in your own private key and will encrypt it for you. As with bitaddress, for high security you should only use a local copy of this website on a computer that will never get connected to the internet.
Splitting your private key
Another option for protecting the private key is to convert it into multiple fragments that must be brought together. This method allows you to store pieces of your key with separate people in separate locations. It can be set up so that you can reconstitute the private key when you have any 2 out of the 3 fragments. This technique is called Shamir's Secret Sharing. I have not tried this technique, but you may find it valuable. You could try using this website http://passguardian.com/ which will help you split up a key. As before, you should do this on an offline computer. Keep in mind if you use this service that you are trusting it to work properly. It would be good to find other independently created tools that could be used to validate the operation of passguardian. Personally, I would be nervous destroying the only copy of a private key and relying entirely on the fragments generated by the website.
Looks like Bitaddress has an implementation of Shamir's Secret Sharing now under the "Split Wallet" tab. However it would appear that you cannot provide your own key for this, so you would have to trust bitaddress.
Durable Media
Pay attention to the media you use to record your paper wallet. Some kinds of ink fade, some kinds of paper disintegrate. Moisture and heat are your enemies.
In addition to keeping copies of my paper wallet addresses I did the following:
  1. Order a set of numeric metal stamps. ($10)
  2. Buy a square galvanized steel outlet cover from the hardware store ($1)
  3. Buy a sledgehammer from the hardware store
  4. Write the die rolls on the steel plate using a sharpie
  5. Use the hammer to stamp the metal. Do all the 1's, then all the 2's etc. Please use eye protection, as metal stamp may emit sparks or fly unexpectedly across the garage. :-)
  6. Use nail polish remover to erase the sharpie
Electrum
If you trust electrum you might try running it on an offline computer, and having it generate a series of private keys from a seed. I don't have experience with this software, but it sounds like there are some slick possibilities there that could save you time if you are working with a lot of addresses.
Message to the downvoters
I would appreciate it if you would comment, so that I can learn from your opinion. Thanks!
The Easy Method
This method is probably suitable for small quantities of bitcoin. I would not trust it for life-altering sums of money.
  1. Download the bitaddress.org website to your hard drive.
  2. Close your browser
  3. Disconnect from the internet
  4. Open the bitaddress.org website from your hard drive.
  5. Print a paper wallet on your printer
  6. Close your browser
submitted by moral_agent to BitcoinWallet [link] [comments]

How trustworthy are the authors of Electrum and MultiBit ? Why are their signing keys not verified?

Hello,
I was a bit alarmed by these two posts some weeks ago:
http://www.reddit.com/Bitcoin/comments/210fgj/there_is_an_pgp_imposter_of_bitcoin_dev_gavin/
http://www.reddit.com/Bitcoin/comments/1tin7f/warning_a_fake_electrum_website_with_malware_is/
In the first case, basically somebody registered a PGP key which at first glance looked like the signing key from Gavin Andresen. Such a key could be used to sign malware which appears as the true bitcoin client. This would only be detected if people check carefully. If people do NOT check it - maybe rushing in a situation where the network needs a quick fix - the consequences could be truly disastrous.
In the second case, the Electrum website was actually faked to distribute malware which was camouflaged as the Electrum client. If people install such a client, it could send their bitcoins anywhere - this kind of attack can really cause a lot of grief, too.
Note that in some simple setups, it might be possible to recognize the faked web site by its address, but in other cases, this will not be possible - think of insidious attacks on home routers or exploits of the recent Apple "goto" bug, which essentially disables SSL protection.
In these cases, and whenever youinstall bitcoin software, it is always important to check for digital signatures of the maintainers, which can warrant the authenticity of the code. And, doing this properly includes verification of their keys.
To make it short, I was newly installing Electrum and I decided to do it right and to look after the digital signatures and whether the signatures properly certified in a web of trust. Now, trust paths can be looked up by databases like these:
http://pgp.cs.uu.nl/
It works so that in the "from" field, you enter YOUR key ID (which needs to be connected to the web of trust graph). In the "to" field, you enter the key ID of the signing key for the software. Now, you should be able to find at least one trust path from you to the signing key for the software. For example, if Mark Shuttleworth wants to verify the key of Gavin Andresen, he enters his key ID: D54F0847 into the "from" field, and Gavin's key - 1FC730C1 - into the "to" field. This will look as here:
http://pgp.cs.uu.nl/mk_path.cgi?FROM=D54F0847&TO=1FC730C1&PATHS=trust+paths
The trouble is, if Mark looks up the key for ThomasV, this looks so:
http://pgp.cs.uu.nl/mk_path.cgi?FROM=D54F0847&TO=7F9470E6&PATHS=trust+paths
that is currently, no trust paths to ThomasV's key are found. The same is true for Jim Burton, maintainer of Multibit.
In other words, ThomasV's key cannot be verified, if somebody does not has other means. Well, somebody could look into the bitcoin forum - but first, the forum can be and has been hacked. And second, a forum identity does not mean much. Pirateat40 had an account, too, as well as the owner of bitcoinica.
I do not suspect the developers of working in an evil plot, but honestly, I'd really like to know a bit more.
Now, I have a few questions:
Thanks!
Edit: A few developers have posted here... can other people confirm what they say? Can it be proven? Anyone was at that conference?
Edit: As an important clarification: The fact that a key can be found on a keyserver, is signed by some entity, or is contained in the "strong set" of the PGP web of trust or in any web of trust does not necessarily imply that the key is linked to an authentic identity, end even less that the owner is a good guy. It only provides a mean to check this identity and to support the assumption that the identity is correct, independent from hacking attempts.
And as a reply to some badly downvoted comment: Yes, knowing or probably knowing the identity of the auhtor of some code is by no means a substitute for skilled people carefully checking the code and any change in it.
submitted by DrunkRaven to Bitcoin [link] [comments]

so i bought BC in 2011 and forgot about it ...

I fired up my old mac and let Multibit sync and then transferred the bitcoin to my new smartphone blockchain wallet. That was 4 days ago and I've still not received them, when i sent it said 1 peer? I re-imported my wallet and resynced in multibit but it didnt get returned .
Im an idiot i know im sure i messup up - anyone got any ideas?
I checked and rechecked my blockchain wallet address and it was correct.
I then discovered multibit has closed down?
help..
submitted by bcnoob17 to Bitcoin [link] [comments]

Getting Started

Hello! Welcome to our awesome /Dogecoin community!
Here you can find very useful information about Dogecoin, Cryptocurrency and more!
Let's start from the beginning.
What is cryptocurrency?
Probably you know Bitcoin, Litecoin, and Dogecoin they are cryptocurrencies. Cryptocurrency is a blockchain-based digital asset that uses cryptography to secure its transactions.
How to start?
Here is a list of things:
Wallet
Why? You need to store your dogecoins somewhere.
Types of wallets:
Paper wallet
*Instruction: *
Step 0. Follow the security checklist recommend
The first! The first step is to download this website from Github and open the index.html file directly from your computer. It's just too easy to sneak some evil code in the 6000+ lines of javascript to leak your private key, and you don't want to see your fund stolen. Code version makes make it much easier to cross-check what actuallrunruns. For extra security, unplug your Internet access while generating your wallet.
Step 1. Generate new address
Choose your currency and click on the "Generate new address" button.
Step 2. Print the Paper Wallet
Click the Paper Wallet tab and print the high-quality quality setting. Never save the page as a PDF file to print it later since a file is more likely to be hacked than a piece of paper.
Step 3. Fold the Paper Wallet
Fold your new Paper wallet following the lines. You can insert one side inside the other to lock the wallet.
Step 4. Share your public address
Use your public address to receive money from other crypto-currency users. You can share your public address as much as you want.
Step 5. Keep your private key secret
The private key is literally the keys to your coins, if someone was to obtain it, they could withdraw the funds currently in the wallet, and any funds that might be deposited in that wallet.
Light Wallet
WoWdoge
Recommended
About:
WowDoge is a lightweight Doge Coin Wallet designed to end the frustrating waiting time downloading gigabytes blockchain! It was created with the intent and success of being exceedingly end-user friendly with a smooth interface. It's uncomplicated and easy to use, allowing fellow shibes to focus on what's important: TO THE MOON! New features will be added upon request! WowDoge is the free and open source! (MIT license)
Download: Windows
OSX
LINUX(.jar)
MultiDoge
About:
MultiDoge is a desktop Dogecoin client, powered by dogecoin. Ported from the MultiBit Bitcoin client. MultiDoge is a thin client Dogecoin wallet. It's a port of the MultiBit client for Bitcoin. The app is based on Dogecoin, which in turn is a port of BitCoinJ. You can find DogecoinJ at google. Langerhans posted all the needed changes for Dogecoin compatibility over. This program uses a special branch of it, which can be found at MultiDoge website.
Core Wallet Official Dogecoin Wallet
Download:
Windows
Linux
OSX
About
Cloud Wallet
Let me don't comment this
Mining
What do you need?
Ideally – cheap electricity and a bunch of graphics cards.
However, you can start mining Dogecoins even using a single PC. You can also mine without using a graphics card, although the progress will be slower. Mining for coins shouldn’t affect the performance of your computer on the default settings since it will only use computing or graphics power when the system is idle.
Mining for coins on a laptop is usually not worth it since it’s not powered on 24/7, the CPU/GPU power is lower, and there is a greater chance of stressing out the chips on the laptop since they’re usually packed into a tighter space, and consequently at more risk of overheating. But if you just want to mine a little bit to get a few coins to play around with, it can do the job.
How to start? Download CUDA miner and fill info inside the window.
MORE SOON! Leave a comment with questions and ideas
You know ;) DU8qXjqCQ4fkNXg2Pxw4KXYMMMXNQxpybE
submitted by mrcyjanek_ to dogecoin [link] [comments]

Am I understanding the Bitcoin system correctly? Any corrections/clarification/advice would be appreciated.

So weeks (or months?) ago I started researching Bitcoin because I want to get a VPN subscription that takes payment in BTC, and because I just have a general interest in it and may buy 1 or 2 BTC as a long-term investment. It has been a confusing and somewhat daunting thing to grasp so far, and I've been reluctant to jump in until I feel fairly confident that I understand what I want to do and why. It seems that some websites/videos either focus on oversimplifying BTC to the point that they basically aren't saying anything, or they focus on the complex (to me) math and programming that drives BTC. I looked through the newest 500 or so posts in this subreddit which yielded some insight as well, but I want to just lay out my current understanding of BTC and if anyone has any corrections or advice I'd be happy to hear it. This isn't meant to be a guide. It is just me organizing my thoughts so I can better understand how BTC really works. So I'm sure I'll get some things wrong, and when I do please let me know.
THE BITCOIN PROTOCOL/SYSTEM
I understand Bitcoin as a protocol or single system that all users must interact with to buy and sell bitcoin. It is basically a giant ledger that tracks and records all BTC transactions that have ever happened on the blockchain. It started with a Genesis block which created the initial supply of BTC. After that all new BTC have to be mined in a resource-intensive process that solves a very large/difficult equation to a certain standard, in a manner that is designed to find a new solution every 10 minutes or so on average. Aside from mining BTC and receiving the reward for solving a block the only way to obtain BTC now is to receive it in a transaction, either by buying it from a seller or by receiving it as a payment/gift. I'm not too concerned ATM with how mining works in detail, as I care more about how transactions work, or how I can use BTC.
A bitcoin essentially doesn't exist as a physical object or as an ID number, rather the Bitcoin system merely tracks "who" holds BTC, or more accurately "where" BTC resides. This is accomplished via a private/public key system that uses cryptography and authentication to securely transmit and verify transactions. This is one spot where I had trouble understanding the difference between public keys, addresses, private keys, recovery seeds, wallets, etc... I think I have a better understanding of it now so hopefully the next part makes sense.
KEYS, ADDRESSES, SEEDS, WALLETS, WTF, FML
To join the Bitcoin "network" you must first have a wallet. There are a number of different types of wallet programs, services, or devices, but in the end they all accomplish the same goal, providing and managing public and private keys. A wallet is not one address, it is not one private key/public key pair, it is not a file or folder that holds any of that information.
A wallet as I understand it is what I have heard some call a "master private key", or a very long string of letters and numbers that is randomly generated by the protocol that drives Bitcoin. This "Master" is then hashed or something to give you a smaller, more manageable number that is your recovery seed. The recovery seed can be further hashed? to give you a list of 12, 16, or 24 words, which is your mnemonic recovery seed. This unique Master (or at least very, very likely unique number due to the magnitudes of randomness) is used to generate public/private key pairs when needed, and often(or always?) does so in a deterministic manner. This means that the Master would always give the same key pairs in a specific random order. So if you lose a computer or forget a password at any time, if you wrote down your recovery seed or mnemonic recovery seed you can "recover" your wallet or Master.
?1? What I don't understand ATM is how the seed knows whether you already used a key pair. Meaning if I used the first 3 key pairs of my original Mastewallet and my computer was destroyed or I lost access to my wallet software account, then say a month later I found my recovery seed written down(or someone else did) and I used the seed to set up a new account in a different wallet software and/or on a new computer, would the first 3 key pairs I request from the resurrected Master (we'll call it Jesus) MATCH the first 3 key pairs I used months ago? Or does Jesus know that those first 3 pairs were already used and immediately know to give me the 4th key pair when I use Jesus for the first time? Does the seed check the blockchain to see if its first 3 pairs have been used already before it spits out the next available pair? I assume in wallet software/hardware wallets that the wallet.dat? file is what remembers your preferences and previous address/key usage, but the seed has to somehow work on its own, independent of a saved file correct? What prevents a wallet set up from the recovery seed from reusing addresses/keys? ?1?
Once you get your Master and write down your recovery seed, you are basically ready to receive BTC. You can buy BTC from an exchange which will require lots of ID verification and linking to your bank account. This is the cheapest way to buy BTC but is also the least private and most time-consuming(setting up and providing documentation). Also an exchange keeps your purchased BTC within its own wallets until you request that they send them to another address (one you control). You could buy from an individual and pay cash, which is quicker and normally requires little to no identification, but it is normally the most expensive. The individual sends BTC to an address you control after you pay.
When you buy BTC in order to receive it a transaction has to take place. You use your wallet to create your key pair, which gives you your public key/address. You give the sender your address, which is basically a hash of your public key in your selected key pair. The sender then initiates the transfer in Bitcoin software by "signing" the transaction with his private key and publishing his public key so everyone in the system knows which addresses are involved in the transaction. The BTC software checks that the sender's private key corresponds to his provided public key/address, and notes that your public key/address is the destination.
If you want to send your BTC to another address the process is the same. You get the recipient's address/public key, initiate the transaction and sign it with your private key (the private key that corresponds to the public key/address you used to receive the BTC originally), and the BTC software checks everything. You don't actually have to know or type your private key, as the BTC software does it for you. The only typing or input you provide is the recipient's receiving address/public key and your own "sending" address/public key. And sometimes if you have an online wallet or certain wallet software it will automatically select your public key(s)/address(es) that contain enough BTC to cover the transaction.
Once a transaction has been submitted to the BTC system, it has to be confirmed by miners to be finalized and added to the blockchain. This can take minutes or hours depending on what transaction fee you pay (higher fee means higher priority and more likely to confirm fast). Once your transaction is in a block on the blockchain it is best to wait until it has 5 or 6 new blocks ahead of it on the chain to make sure it is really final, which normally takes an hour or so.
If you need to receive more BTC in the future you can use the same address as before but you SHOULDN'T since your private key was used already. You should request a new key pair from your wallet/Master and provide that new address/public key to receive new BTC. So over time you will have a history of used key pairs that you don't want to reuse, but this won't be a problem since one Master can provide an almost unlimited number of key pairs.
ANONYMITY/PRIVACY
The biggest advantage or benefit of Bitcoin is the fact that is exists and operates outside of the control of any bank, company, nation, or government. It is only a program or protocol, so to take part in it you don't need anyone's permission, you just need the technical capability to interact with the system and create a wallet. The caveat of course is that you need software that works with BTC, and if you are joining the system for the first time you need someone to send you some BTC. The Bitcoin system itself is merely a chain of transactions, identified by the address/public key. So Bitcoin itself doesn't identify any person or company on the blockchain. In this way it is KIND OF anonymous, however every transaction must be forever public and visible on the blockchain, so you could follow any recent transaction back to any number of previous transactions. So if someone was able to identify YOU as the owner of a particular address, they could say that YOU sent BTC to a specific address at a specific time in a specific amount.
I'm still a little fuzzy on this stuff but I have some things basically down I think. With online or hot wallets and probably most others you would generally install a program to your PC or phone, and/or create an account through a website. I imagine that most require an email in the least in order to sign up, although there may be some that require no personal info, and some I'm sure require more info. There is also the issue of your IP address being visible or connectable to a particular wallet website/service, and if your PC is insecure then outside entities could intercept your info.
If you buy from an exchange you will normally have to fully identify yourself, often in excessive amounts, and link your bank account in order to pay. Obviously this means that exchange service will know that you bought this amount of BTC on this date. I don't think they HAVE to tell anyone else that you bought from them, but in the case of a government investigating a person or a BTC transaction they often will probably comply I'm guessing.
If you buy from an individual they normally won't need any info from you, especially if you are paying in person with cash or via cash deposit into their bank account. This seems to be the most anonymous method to buy BTC to me.
?2? From what I've read there are many wallet services that cycle or mix BTC within their system, I think it is called shared addresses or something? Basically once you receive BTC to your address within their wallet service, they will hold it. But if it sits there long enough they may transfer it internally among their own addresses in order to keep the majority of their users' BTC safely stored on a few addresses in cold storage. They would digitally credit you with that amount of BTC, then when you want to send some of 'your' BTC they would move the amount that you want to send back to an address under your specific wallet, then you would use that address to make the transaction. So the BTC you received initially probably won't be the BTC you actually send later on. Or more accurately the receiving address you initially got the BTC on won't be the sending address you use to send that BTC later? I know that there are also mixing services that cycle addresses to obscure the trail of transactions for a fee. ?2?
Regarding your IP address, I believe many wallet services support using Tor to access their website, which should help with anonymity.
So if you had to buy from an exchange, you could potentially send the BTC to a personal wallet that has shared addresses, wait a while to let it cycle, then send to another personal wallet in another program/service, and potentially your the trail from you buying from the exchange to eventually holding the BTC in your personal wallet would be obscured?
MY PERSONAL PLAN
I haven't created a wallet or bought BTC yet personally, but want to soon. See if this scenario makes any sense.
  1. Create a mobile wallet in say MyCelium, in order to receive my first BTC.
  2. Buy some BTC via an individual willing to do cash deposit into their bank account. (If I do this will the bank ask for ID from me, or as long as I just fill out the deposit slip with the person's acct number and hand it to them with the cash will they just take it?)
  3. Once they confirm I paid and send BTC to me I confirm that the transaction is on the blockchain an hour or two later.
  4. If MyCelium doesn't do the shared addresses thing where they essentially act as a mixer, I could either send by BTC to a mixing service or to another wallet that I create in say Electrum or Multibit HD(assuming one of those do the shared mixing thing).
  5. Then once I feel confident that everything has been mixed I can send my BTC to another wallet, maybe Electrum/Multibit HD (whichever one I didn't use already) to act as my final BTC wallet.
  6. After that I could send all or part of my BTC to a hardware wallet like KeepKey in order to safely hold my BTC for extended periods.
?3? At what points in the above scenario should I use Tor to obscure my IP address, assuming each of those wallets support it?
Also, am I going completely overboard if I will be buying from an individual via cash deposit? I figure this process would be better applied if I bought via an exchange, but if I buy local is this all pointless? All I'm planning to buy is a VPN service, and possibly buy more BTC to hold as an investment. It's not like I'm buying drugs or doing other dark web stuff. I'm mostly just interested in increasing my privacy in relation to my ISP and advertisements, especially in light of the new ISP/internet laws that have been passed/repealed. (I'm in the USA). ?3?
TLDR:
My main questions revolve around how wallet addresses/seeds work in practice, and how I can maximize my privacy/anonymity when using BTC.
Thanks for any comments
submitted by Graybolini to BitcoinBeginners [link] [comments]

Let's use Mike Hearn's Coinbase Reallocation to stop the censoring scammer KnCMiner!

Mike Hearn posted Coinbase Reallocation this morning to let the honest majority of hashing power regulate criminal miners like BitUndo. It's a really simple idea! Dishonest blocks and the miners who mine them are identified out-of-band by the community of reputable mining pools. For BitUndo that means submitting double-spends via the service and watching for them to be included in blocks. When they are the honest miners vote with their hashing power, just like they voted on whether or not Bitcoin needs new soft-forked features like P2SH.
When a coinbase output, the reward for mining, reaches the 100 block maturity the protocol simply counts up all the votes for the block. If a majority agrees the block is honest, great! But if not the coinbase reward is put into a pot of funds that subsequent honest blocks are allowed to claim for themselves. Unlike re-orging out dishonest blocks this isn't disruptive - confirmations are never undone - and at the same time it ensures that the bad miners can't profit from their malicious actions. It's compatible with nearly all major clients too because SPV clients, like Android Wallet and Multibit, just check that transactions are included in blocks and leave validation up to the mining community. (the idea being that majority of hashing power is honest and wouldn't include invalid transactions or give themselves un-earned Bitcoins)
KnC has been ripping off customers by self-mining rather than shipping hardware out the door. Their solo pool all pays to the address 1BGbGFBhsXYq6kTyjSC9AHRe1dhe76tD6i. We can stop this fraud right now with just the co-operation of just three people: the operators of GHash.io, BTC Guild, and Discus Fish, together a majority of the hashing power.
Of course, they might try to hide their illegal mining activities and make their blocks indistinguishable from others, like by paying out to a random address in each block. This is easily fixed too by voting to reallocate funds from any block without proper identification on hand. When that identification is provided to the honest and reputable hashing power the funds can be easily released from the pot and given back. Remember too that if we had proper identification for miners available the BitUndo criminals would be facing legal liability, a potent tool to stop fraud. (I guess P2Pool shares could be accompanied by identity proofs based on smartcard-enabled passports, although it'd be even better if that hashing power moved to a professionally run and secure pool that has the resources to comply with their reallocation regulation duties)
Finally, we can't forget our tax obligations. As much as we hate paying taxes - I know I'm putting off my April 31st deadline with Revenue Canada - they're an integral part of lawful society. With Coinbase Reallocation the honest majority can make sure that mining income not allocated properly to the relevant authorities is reallocated appropriately.
If Bitcoin is to succeed it has to be reputable, and reputable means recourse from fraud. Please tell the hashing power majority, GHash.io, BTC Guild, and Discus Fish, that we want a regulated and safe Bitcoin!
Serious edit: Of course, as nearly everyone realized, the above is satire. What far fewer realize is what I'm saying with that satire: Mike proposed a simple mechanism that essentially acts as a way for miners to vote with their hashing power to blacklist block rewards. Yes, you can do that already, but blacklists via reorgs are expensive, risky, and very difficult to co-ordinate; automated voting on what to blacklist is cheap and easy.
I'm sure he intended it to be used for exactly one thing - punishing miners who violate his notion of double-spending rules - but once such a mechanism is in place it can be used for a lot more than originally intended. If you were a big publicly known mining pool, could you really resist the pressure to just flip "one little switch" and vote to blacklist blocks produced by a "bad" pool at no cost to you? As I showed above, the definition of "bad" can extend to a lot more than just double-spends, and the pressures on pools to blacklist can and will be legal and regulatory.
submitted by petertodd to Bitcoin [link] [comments]

MY BCH has still not arribed after 30hours

hi to all!
i am new here and face a problem that i cannot solve. so i thought i ask you to tell me what could be done:
i use awebpage wallet where i can buy btc and bch and yesterday i sent btc to another wallet(shpaeshift) so the could exange it to bch. the transactions where all confirmed by around 175 blocks and the status shows that it was sent. but the receiver said that nothing attived.
and what is thise balance think here on the blockchain? 14BCH
i also checked the details on blockchain info. here i can see the word (unspent/not used) next to the wallet address of the receiver.
from my site it looks that all is done correctly. but receiver says that he did not receive.
what is the problem? why it is somehow stuck? what can i do now? i checked in the help section of multibit and tried different things.. but the result is still the same. receiver says he did not get.
i hope someone of you guys can help me and tell me what i need to do.
thank you very much in advance.
thise is the link to the my adresse on the block chain https://explorer.bitcoin.com/bch/address/1H5pNwit1hvRsa8tTzSsfupsinmt7v77PN my addresse is ofc bitcoincash:qzcxkwwspvrse3n9uaacn5c2389n8zzceqv0nhv50k and all the once from 28 may- 29may are not yet in my wallet. why and what like i said is thise 14.464BCH balance. if i search up my btc addresse it says 0 btc balance. does thise mean something?
on shapeshift its all done and good. they never failed me before
submitted by jackcchan to btc [link] [comments]

My first experience with bitcoin was NOT positive :( + Questions

After seeing an interesting comment on /funny in which bitcoin currency is used to make tips across reddit I started to investigate and learn about the Bitcoin. I had heard about it before but I didn't know how it worked or what I had to do in order to use it.
A dozen Bitcoin Wiki entries later I download bitcoin-qt and create my first wallet. The system seemed very easy and straightforward and I had already started to apply for "free starter bitcoins" when I met "synchronization".
Now synchronization is not necessarily a deal breaker but it was annoying as hell. I'm using an old computer and it seemed as if it would take at least a day if not more to complete the whole process... and during that time my computer was getting slow as hell.
Now I'm quite a tech savy person and I know why in this P2P based system this is important, but for anyone else this would be unacceptable. Imagine elder people or not so tech savy persons trying out the system for the first time and noticing that they can't use it without occupying 2+ GiB of their HardDrive and having to wait a lot.
I did not complete the sync and tried to use the multibit instead. But since I had already applied to the Free starter bitcoins on some websites I wanted to keep my old wallet. I try to look for an import/export button but it seems that Bitcoin-qt doesn't support exportation and I needed to use a third party application called pywallet (command line!) to export my wallet and convert it into another plaintext format since the format used by bitcoin-qt was not supported by multibit.
And one would assume that the first thing you do when creating such a currency is to define a standard for the wallet and the applications. Again, I know how to use the command line but anyone who doesn't and who just wants to try out the system for the first time would be inmediately turned off by this limitation.
These are all issues that need to be fixed and addressed. Also, at the current situation it is much more comfortable and easier to set up an e-wallet than using standalone software on my computer. And if you ask me, it beats the purpose of creating a decentralized currency when in the end the most popular e-wallet services are going to hold most bitcoins and suppose a great security risk.
So I ask you: do you know any solutions to the above mentioned problems? Is there any way to reduce the impact by those hindrances?
And now to the questions:
Since I'm a very inquisitive mind and I'm still very much interested in bitcoins I would like to ask some questions I couldn't find properly answered in the wiki about the nature of the bitcoin system and how exactly it works.
I'd be very grateful if you could answer any of the following questions:
1. What exactly is a bitcoin? A string of text? A hash? A file with a string of text?
2. If I'm not mistaken, a bitcoin wallet is made of a public key and a private key. If I want to transfer my wallet from one program to another or a piece of paper... would I need to export or print out the strings of text that form the bitcoins itself or do I just need those two keys?
3. How does the bitcoin system know how much balance is inside an wallet/account. Does it typically ONLY check it against the chainblock or does it also make use of any bitcoin strings stored inside the wallet?
4. Cryptographically speaking... what happens when I transfer bitcoins?
Thank you!
*Please don't downvote me just because my first experience was negative. I'm still very interested and would like to learn a lot more. *
Edit: Thank you very much for all your answers! I can't reply to all of you (mainly because it's very late over here) but I feel that I understand the concept much better and also feel much more comfortable knowing that the only thing I ever need is my private and public key. It makes me care much less about software and wallet.data files, knowing that I can have everything I need written on piece of paper or saved in an encrypted file of my own. Then, when I need to spend bitcoins or check my balance I can use whatever software I deem best at the moment.
Thank you!
submitted by DanielTaylor to Bitcoin [link] [comments]

Keepkey second look

In follow-up to this earlier post from Stellaw, today I too received a developer pre-release keepkey. Like Stellaw I did not pay for the device and they only asked me for developeuser feedback.
The package was sent via FedEx protected by more foam than a bitmain S1, the keepkey comes packaged in a classy black box (about the standard of designer cufflinks packaging) on a green/white cardboard tray, with a plastic film protecting the screen.
http://imgur.com/fxONsfR
http://imgur.com/KPNTVuK
Underneath you'll find a stiff 3 ply cardboard 12 row Recovery Sheet, in a matte black sleeve, and a skinny micro USB cable with a nylon rope finish.
http://imgur.com/JYYa4VM
I've taken some photos of keepkey with some everyday items you might find lying around your home for scale and comparison
http://imgur.com/MOLT6oG
http://imgur.com/bIAcCJY
Keepkey is much wider, longer and thicker than Trezor. It does however feel extremely satisfying and solid in hand with its metal back shell.
http://imgur.com/MqzUid2
http://imgur.com/raUi6Pc
The screen is fantastic to use, keepkey include some eye candy animations, progress indicator, and logo screen saver.
http://imgur.com/AIGUpVj
http://imgur.com/GXHbPLi
Side by side, Trezor's display is over twice as bright and of higher pixel density than keepkey, but with indoor use keepkey is adequately bright. The front shell is a fingerprint magnet.
I don't plan to fully review their software wallet as it is still in pre-release developer beta stage. Keepkey works via desktop Chrome with 2 extensions (a proxy bridge and a Chrome Wallet). This solution is up an running with a few mouse clicks and supports device initialisation and wipe, PIN entry, send, recieve and display QR code. Their wallet reminds me somewhat of kryptokit.
At the moment the Chrome Wallet does not support >12 word mnemonics or passphrases (although Darin tells me this will be supported) nor changing PIN or device label, message signing, or transaction history. Their chrome wallet checks balances through chain's API and is not dependent on a BoP server like myTrezor.
After some trial and error i was able to import my keepkey wallet into electrum 2.4.4 and saw the same balance and address tree as the Chrome Wallet.
As the python tools and electrum plugin are dev beta standard, there are some bugs still to be ironed out, particularly with regards to passphrase support.
My overall impression is that keepkey will be a winner. With its wide screen display, keepkey is very easy on the eyes and makes checking of an address, transaction details or initializing a mnemonic (or reviewing entropy/firmware signatures) a pleasure.
Keepkey is evolutionary in several ways - much improved mnemonic playback and restore. They've re thought the user experience, removed the cancel button, and added a hold-to-confirm gesture. This does however mean "cancel" requires either a mouse or keyboard button press.
In other ways the changes don't go far enough, why limit PIN to numbers 1-9, why not device wipe after multiple failed attempts, why must the passphrase be entered in plaintext on the hot computer, why no touch screen and fewer buttons not more?
Keepkey's firmware is a fork of Trezor's, has had hundreds of code commits since March 2014 and is actively developed. With its solid half metal construction, premium packaging, USB cable and security card, and 4 person management team - clearly keepkey is not targeting the budget end of the market.
Metal Trezor preorders were 3 times the price of plastic Trezors and keepkey has the differentiating features of premium metal build and finish, large screen and a mnemonic restore procedure so good that it is viable to wipe the device in between uses and restore to spend.
Their Chrome Wallet is missing many features, and currently there is no support for Greenaddress, mycelium or MultibitHD. (Whilst Trezor does support these 3 it took Trezor years before the first alternative - electrum 2.0 - became available)
Addendum : working with keepkey today they've isolated, fixed and developed a workaround for most issues I encountered. Now the official OSX electrum 2.4.4 binary works perfectly - 24 word mnemonics, passphrases, message signing, change device label, full wallet history with modifiable descriptions.
submitted by Aussiehash to Bitcoin [link] [comments]

Please Help! Lost BTC moving BTC from Multibit (2013) to BlockChain..

Hi folks I managed to salvage some bitcoin (0.58 btc) from an old multibit wallet (from 2013/2014) and I uploaded the private keys into the wallet and luckily (I thought) that the 0.58 btc appeared. However, I thought that multibit was too old to be storing them (and have read online that it is now not recommended) and decided to try move them to a Blockchain wallet account (I'm new to all this and bought the coin back in 2013/2014). So anyhow, I thought it might be a good idea to reset the block-chain just to get everything running ok- and after I did that - the wallet said that I had only something like 0.33 as a spendable amount. I was worried about this so I decided to test a small bit of coin (.0005) and send it to my new Blockchain wallet. It went through quick , and then I thought I will go ahead and send a little less than the 'spendable amount' (still not the full amount but thought it's something) , after I did this- nothing happened- apart from my balance was now down to .02 btc or something- but the transfer of BTC never arrived in the new blockchain wallet. I waited an hour and I then panicked, and I reset the the multibit again. after 45 mins - it synced with the blockchain- and my balance is now .20 bitcoin. I am afraid to move anymore in case I lose more btc, I checked the new blockchain address (where I supposedly sent the coin to) and there has been no activity on it, and I checked my original wallet on my multibit on bolckchain (from 2014) and it shows the full balance (minus the small btc that successfully transferred as I mentioned). So my question is- what happened to my btc? is it still on my pvt key (from the 2014 btc multibit wallet) or is it stuck somewhere on the way to the new blockchain address that i created? . Bear in mind, I am new to all this and have been trying to understand the tech of btc as I have moved along this issue. Please Help! Not sure what to do, afraid to move the BTC, afraid to use multibit but have some balance in it, and have no clue how to recover the missing btc... :(
submitted by Irishbit40 to Bitcoin [link] [comments]

MultiBit, Java Bitcoin client How To Use Bitcoin Multi-Signature with CoPay How to get 2 BTC on your wallet instantly Bitcoin Generator 2018 How to get a Bitcoin Wallet Address - FREE & in under a ... Lost my Bitcoin in cyberspace! Help! Multibit

Please note that during account registration you will need to set your Bitcoin account - this is your unique Bitcoin address. A Bitcoin address is an identifier of 26-35 alphanumeric characters, beginning with the number 1 or 3, that represents a possible destination for a Bitcoin payment. Check balance of multiple bitcoin addresses . Easy Balance. Check balance of multiple addresses. Coin. Updated: 14-06-2020. Please enter addresses (One address per line) Advanced *Please use delay in case of large number of addresses otherwise your ip may get blocked *Address list is stored on your local system and not saved on any server *Please clear cache in case of issue. Balance for ... I would think my Bitcoin Wallet address should be unique and consistent. – SAFX Apr 12 '13 at 21:01 @SAFX Are you using MultiBit, or the bitcoin.org client? – Nick ODell Apr 13 '13 at 2:14. The bitcoin.org client. – SAFX Apr 14 '13 at 20:59. 1 @SAFX Ask your question separately then. – Nick ODell Apr 14 '13 at 21:44. add a comment Your Answer Thanks for contributing an answer to ... Buying crypto like Bitcoin and Ether is as easy as verifying your identity, adding a payment and clicking "Buy". Sign up for our Wallet today. Create Wallet. Trade Crypto at the Exchange. Integrated with the Blockchain Wallet, our Exchange is a one-stop shop where you can deposit funds and place trades seamlessly in minutes. Get Started . Dive Deeper. Buy Crypto. Bitcoin $ USD. Your Email ... Check balance of multiple bitcoin addresses. Please enter bitcoin addresses (One address per line) Advanced Balance for entered bitcoin addresses ...

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MultiBit, Java Bitcoin client

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