Import wallet.dat into a new Bitcoin-Qt client - Bitcoin

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]

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]

A proposal of a wallet to the clever developer shibes out there which concerns all and future shibes (Would be extremely beneficial with the Talladega race coming closer and closer)

I recently watched this talk by Andreas Antonopoulos (which I recommend every shibe to watch). In this video he explained how private keys, public keys, adresses, cryptography and wallets work.
In the video, I realized how far wallets have come already, how little the QT-wallet actually matters for us common folks, and how important it is to have user friendly wallets with good features. I got especially intrigued when Alexander explained type 2 deterministic wallets based off of trees. And my question is: "Can you deveolper shibes develop a type 2 deterministic wallet (like electrum) with BIP39?"
For all who don't know what I'm talking about, I will try my best to explain how type 2 deterministic wallets work by basically paraphrasing Andreas from the video. Please correct me if anything is wrong.
Let me begin by saying that our, and every virtual currency QT client is more focused on implementing the stability into the core coin protocol rather than implementing user-based fancy wallet features. Recently the bitcoin QT client has been removed from the bitcoin.org site as the recommended wallet for new users. This is because it isn't a good interface for the common man, or really anyone. It has also been discussed by bitcoin developers to strip all the wallet functionality out of the QT-client just for this reason.
Explaining type 2 deterministic wallets: When creating a private adress, a random number is drawn, in this process you will also generate a 128-bits random seed (for example 521566b6ebfe0ab8ff7b8110b92c57d4). A seed is generally speaking a starting point for the random number generation. This seed will therefore be the generator of all future adresses in your wallet.
From this seed, you can use mathematical functions to generate keys in such a way that you can't predict those keys without having the seed.
Just to clarify: If you have one private key, you can't figure out the other, and if you have the other, you can't figure out the first. This means that as long as your seed and mathematical function is not compromised, your keys won't be compromised. This is because you generate (or regenerate) all your private keys from that seed.
These mathematical functions can for example be the following: "You generate the first key, then you jump over 5 keys, then generate another key etc.". What this leaves us with is that you need two types of information to "infiltrate a wallet": The seed and the gap. This means that the seed and gap still needs to be encrypted, the good thing is that there's no need for a backup if you lose your wallet because you know your seed, and the gap.
Now you might be wondering: "How am I going to remember my seed? Won't this be hard? Won't it be a pain to remember?" Well there is also a new really interesting implemented technology called BIP 39. What this technology does is that it creates 12 random words (called a 12-word mnemonic code). These words are deterministically derived, in this way you can convert those 12 words back to the seed.
Let me give you of an example of why this is beneficial: The first thing is that 12 random words are much easier to remember and hear than a combination of 12 random letters and numbers. This means that if you lose your wallet and you're away from where your seed is written down/stored etc., you can for example call someone you trust to help you to restore your wallet. This can be done by the person telling you the 12 words over the phone, which will again give you your seed. No need to wonder if the person said "b" or "d".
The mnemonic code for the seed I wrote down (521566b6ebfe0ab8ff7b8110b92c57d4) is "pain apologize tired bar change think off outside clear fear hot stir". You can see how this could be handy.
This is technology is at the moment restricted to the English language. More importantly, it is restricted to a specific dictionary. The reason for this is because based on those specifications, every single wallet in the world with these features can take 12 words with the gap and deterministically recreate the same seed. From this point it can then recreate the same keys.
There's of course a checksum built in, so one of the words is a checksum for the other words. This entails that not every combination you throw at it will be correct. This means that if you remember those 12 words in that specific order, you will never have to take a backup of your wallet ever again. How great is that?
So a TL:DR:
I want our smart and clever developer shibes to create a type 2 deterministic wallet with BIP39 (like electrum or armory) with a great design. This would make it much easier for both newcomers and old shibes to use their wallets. The problem with backing up you wallet would also be a thing in the past. And if you know your seed or mnemonic code, you can import your wallet with extreme ease to any other device with a wallet just by typing in some words instead of moving a backup file to your device. If this wallet is being based on a litewallet, there will also be no need for synchronisation.
Disclaimer: Like I said, I'm not a pro at this, please correct me if anything is wrong here. And please shibes discuss, is this something the community is also interested in? I would be so happy if we got a wallet like this.
submitted by ChaotropicVindicator to dogecoin [link] [comments]

mSigna unsent transaction (lost funds?)

I am having a problem with my first transaction with Msigna and am looking for help. I have been unable to find an answer by searching the internet so I am writing this post. I sent a transaction to an address I wish to send funds to but the confirmation status is “unsent” after several hours of waiting. I am running Bitcoin-Qt and the blockchain is completely downloaded and synced. The icon in Msigna is a green circle with a check in it and it is connected. However the funds seem to be stuck locally and have not appeared in blockchain.info. I have installed the latest version and imported my vault (and updated schema) but the status remains the same. Am I doing something wrong? How do I recover my un-sent funds? How do I export the private keys so that I can import into another wallet like Multibit or Armory? Any help would be greatly appreciated… Thanks!!
submitted by waybackwhen007 to Bitcoin [link] [comments]

A helpful discussion about wallet security (esp. Electrum)

I was recently contacted via private message by a redditor who read a comment of mine about wallet storage (I assume this comment). I think there was quite a bit of useful information in it for other bitcoin beginners, so I am reposting it here in full (with permission). The redditor in question wanted to remain anonymous though.
I hope this is of use to some of you here!
From: Anonymous Redditor
I saw your post regarding your wallet storage and had a few noob questions if you don't mind.
My plan is similar to yours but I was unsure whether to use armory or electrum (electrum's seed creation scares me a bit).
You mentioned you have a bootable LINUX (ubuntu?) USB stick that you keep your wallet on....do you only boot this onto an always offline computer?
Do you use something like Truecrypt to further protect your wallet.dats?
Thanks for your time!
From: SanderMarechal
My plan is similar to yours but I was unsure whether to use armory or electrum (electrum's seed creation scares me a bit).
For me it is the other way around. Armory (and bitcoin-qt) scare me. Armory is just a wallet. It still needs bitcoin-qt running in the background. For me the problem is two-fold:
1) Size
bitcoin-qt (and armory) need to download the entire blockchain. That 13+ GB that takes hours to download and days to verify. And if you ever lose it, you need to do it again.
2) Random keys
armory and bitcoin-qt generate random private keys. You get 100. If you use a few (you use them when you send coins for example) then new ones are created. So, if you create an armory wallet and make a backup, that backup will have 100 keys. Then, if you make 33(!) transactions, your 100 keys are used up and you will have 100 different random keys. If someone then steals your computer (or your house burns down) then you cannot use your backup anymore. It only has the 100 old keys and none of the new keys. So you have lost all your bitcoins.
Why 33 transactions and not 100? Because of change addresses. If you have 10 BTC and send me 2 BTC then most wallets will create 2 transactions. 2 BTC from your old addres to me, and 8 BTC from your old address to a new (random) address. This process costs 3 private keys. 2 keys for the transactions and 1 key to create a new address.
This means that after every few dozen transactions you need to refresh your backup so it has the newer keys. For me that is impractical. It means that I need to keep my backup close by because I often need it.
Electrum does not have this problem. The seed solves this. Private keys are not random but are created from the seed. If you have the seed then you have, by definition, all the private keys you will ever need. Your backup can never be out-of-date. This is easy for me. I save the seed in a file, encrypt it, put it on an USB stick and give copies to a few family members who have safes in their homes.
If my computer is ever stolen, or my house burns down, I can go to a family member, decrypt the seed file and use the seed to restore my electrum wallet. Even if that USB stick is 10 years old.
You mentioned you have a bootable LINUX (ubuntu?) USB stick that you keep your wallet on....do you only boot this onto an always offline computer?
It depends on how secure you want to be. For maximum security, keep the computer always offline. But if you want to spend the bitcoins from your wallet, you will need to be online.
I use the USB stick for my savings account. It only receives coins and I do not send. So I do not need to boot up my USB stick. I have created a second wallet on blockchain.info that I use for day-to-day transactions. All BTC I receive goes to my blockchain account. Then I transfer a part of that to my savings account and only keep a bit of change that I need in the blockchain account.
Do you use something like Truecrypt to further protect your wallet.dats?
No. Electrum does not have a wallet.dat. It has the seed. I simply copy the seed to a TXT file and encrypt it using GPG and symmetric encryption. Example:
gpg --armor --symmetric --cipher-algo AES256 seed.txt 
Make sure you use a password that is strong and that you cannot forget! If you need to write the password down on paper and your house burns down, then you cannot decrypt the seed anymore!
From: Anonymous Redditor
Forgive the naivety here: Correct me if I'm wrong - The safest way to generate your wallet seed is on an offline computer correct? So, theoretically, generate the seed on an offline-only computer, copy to txt...encrypt. back up on multiple USB's. Then on your online computer, load electrum and import Seed?
Thanks so much for the thorough explanation! I'm a potato when it comes to reddit's bitcoin tip bot. Send me an address - would like to send some internet magic money your way.
From: SanderMarechal
The safest way to generate your wallet seed is on an offline computer correct? So, theoretically, generate the seed on an offline-only computer, copy to txt...encrypt. back up on multiple USB's. Then on your online computer, load electrum and import Seed?
Not quite. The risk with an online computer is malware and people breaking in. If you generate the seed on an offline computer and then move it to an online computer, you don't really take that risk away. You still have your wallet on an online computer which you use for day-to-day work and which is exposed to hackers and malware.
I suggest you make two wallets. One wallet is your "savings" wallet. You can use the USB stick Linux for this. Generate the wallet offline, backup and encrypt the seed onto multiple USB sticks and note down the bitcoin address somewhere so you can transfer funds to it. The only time you should use the USB stick to go online is when you want to transfer funds out of your savings wallet.
The, on your normal computer (or your smartphone if you prefer), create a second wallet using a different password. This is the wallet you keep only a little money in for your day-to-day transactions. Note down the seen, encrypt (with a different password than you used to encrypt the seed from your savings wallet) and add it to the USB keys. You can use Electrun for this second wallet as well, but you can also use something different. I use a blockchain.info wallet for my day-to-day expenses.
Whenever you have a larger amount of bitcoins in your day-to-day wallet, transfer some to the wallet on the USB stick. You don't need to boot up the USB stick for this. You only need the address you wrote down.
When you want to spend a large amount of money, boot up from the USB stick and transfer coins from your savings wallet to your day-to-day wallet. Reboot into your normal computer and use the day-to-day wallet to pay for what you wanted to buy.
The core of the issue is simple: Don't store a lot of money in a wallet on a computer that you use a lot. Computers that are used a lot get attacked a lot. Simple :-)
Thanks so much for the thorough explanation! I'm a potato when it comes to reddit's bitcoin tip bot. Send me an address - would like to send some internet magic money your way.
That is very kind! My address is: 1PAXiscvKoGRJ5XxMZvri3CMNeKYYb8wMQ
From: Anonymous Redditor
You are awesome:) Thank you again for the insight! Sent some your way.
From: SanderMarechal*
Your welcome. And thanks for the coin!
From: Anonymous Redditor
Last question(s) (I promise)...
Would a netbook like this be appropriate to 1)dban 2) boot up via USB ubuntu and 3) create the electrum seed?
This would of course never go online, be backed up and encrypted, etc.
http://www.newegg.com/Product/Product.aspx?Item=N82E16834131403
Thanks again.
From: SanderMarechal
I don't know. You would be better off asking this on www.ubuntuforums.org for example. I don't know if that computer's hardware is compatible with Ubuntu. Speed-wise the bottleneck will be the USB stick and not the CPU or memory. USB sticks are much slower than hard drives.
Note that you don't have to buy a computer for this. You can use the computer you already have and still run Ubuntu off an USB stick for your Electrum wallet.
What I said in my previous post about not using your day-to-day computer for your wallet, with that I mean the operating system and software. Not the hardware. Unless you're afraid someone put a hardware keylogger inside your computer :-)
From: Anonymous Redditor
Fascinating!
My tin foil hat is in full effect:) Thanks again for your time and patience.
From: SanderMarechal
Your welcome. Have fun with bitcoin!
Oh, I have a question for you now. Would you mind if I repost our entire private conversation here to /BitcoinBeginners? I think other redditors there would also be interested. And if I can repost it, do you want your username in there or should I replace it with "Anonymous Redditor" or something?
From: Anonymous Redditor
You can certainly repost it! And yes, if you wouldn't mind removing the username I would very much appreciate it.
Thanks for asking btw!
Anyway, I hope this is useful for some people out here.
submitted by SanderMarechal to BitcoinBeginners [link] [comments]

How can I view the balance of all addresses in multiple wallet.dat files?

So I created a wallet.dat file years ago using the original Bitcoin QT client, then copied that wallet to two different computers. Occasionally I would send coins out of that wallet from either computer. I periodically made backups of the wallet file from either computer. What I learned later was that sometimes the change from a transaction would go into a new address. The two wallets would then potentially be out of sync if an address existed in one and not the other.
Now that I have all these periodic backups of wallet.dat files, I simply want to import them into one client where I can observe their collective balance. They are encrypted wallets. Is Armory the right client for this? Do I use the import function? Watch-only? I've never used Armory or any other desktop client other than Bitcoin QT / Core.
To clarify, I don't seek to use a new client, I wish to continue using the standard client. I just don't want to move any coins or alter the access to the coins in the client I've been using.
Thanks!
submitted by TwinTurboMike to Bitcoin [link] [comments]

Hopefully I can help clarify the relationship between bitcoins, addresses, and wallets before you lose your coins.

I've seen a few posts here from people who accidentally lose their bitcoins. With the recent ~100$/BTC there will probably be more people getting interested in bitcoins, and hopefully this can help you keep any bitcoins you receive:
There aren't specific bitcoins floating around. All bitcoins belong to an address somewhere. Any "lost" bitcoins are just any public addresses that the owner lost the private key for, and thus cannot spend these bitcoins.
Lets say I got 1 BTC from someone for whatever reason, and I want to send you 0.5 BTC. The blockchain is just a big sequence of transactions, so I basically add a new transaction that:
A) Proves I was the recipient of that transaction for 1 BTC, and therefore have enough to cover my 0.5 BTC transaction I'm about to make.
B) Says where I should send the BTC.
Since I can only reference the 1 BTC transaction, I need to spend all or none of it at the same time (and, actually, any that is not sent to a specific address is actually the fee and the miner can claim). I can send 0.5 BTC to you, and if I want to keep the other 0.5 BTC, I need to send it back to myself.
This is where people can lose bitcoins if they aren't careful
Different clients handle the process of sending this "change" back to yourself in different ways. Some clients, like the official Bitcoin-Qt client, make new random addresses and send the change to them. You still control those addresses, but you need to make periodic backups because these new addresses have new private keys too.
Other clients will send the change back to the address that sent it, or give you the choice to choose where to send the change. I think the blockchain.info wallets are like this.
The first strategy increases the anonymity of bitcoin transactions, but makes you keep track of new private keys. The second strategy does the opposite.
The reason some people have lost bitcoins with brain wallets is because they try sending a small portion of their BTC to someone from the brain wallet address, and don't realize the change might get sent somewhere other than their brain wallet. "Brain address" might be a better term, actually.
One last note: Some clients, like Armory or Electrum (I haven't used Electrum but I believe it is similar), will show you yet a different key that generates ALL the addresses in your wallet. You only need a backup once of this key, since you can import the wallet into the same client on another computer, and it will generate the exact same sequence of addresses that change is sent to, rather than random addresses. These are called deterministic wallets, since the pattern of addresses created looks random but can be reproduced multiple times as long as you have the original key.
I realize it can get confusing. I'm not sure if I am explaining it correctly, or even if I completely understand it myself. If you have questions though, I can try to answer them.
submitted by maccam912 to Bitcoin [link] [comments]

Sure Bitcoin is safe Grandma. This is all you have to do to really secure your money

THIS IS FUCKED. BITCOIN HAS NO FUTURE IF WE CAN'T FIND A BETTER WAY TO MAKE IT SECURE. MAIN STREET WILL RUN A MILE FROM IT.
Xpost from: http://www.reddit.com/Bitcoin/comments/1d26gw/cold_storage_how_i_did_it/
With the recent events surrounding blockchain.info wallet attacks, I decided to bite the bullet and send all my coins to my cold wallet. It's a bit nerve wrecking but I managed. Here's what I did:
Download offline version of Armory here[1] (section Linux – Offline Bundle for Ubuntu 10.04)
Download Brainwallet source from github[2] for signing transactions, rather than the suggested way from armory website, since I don't want to run a full Bitcoin-qt client + armory to create an unsigned tx. More on this later
Prepare a USB pendrive for linux here[3] using the suggested Ubuntu 10.04 by Armory.
Boot into Linux using that pendrive. Install the Armory software and generate a new wallet. Make sure you make appropriate backup (paper copy or just write down the seed). You can always regenerate your entire wallet via brainwallet.org copy (tab Chains).
If you want, make a watch only copy of your wallet, and you can get all the public address in that wallet from your online computer via Armory offline version. Save the watch only wallet on your windows partition.
Reboot into windows/mac/your main OS.
Install armory and import the watch only wallet to see all of your addresses.
Try to move a small fund into one of the cold-storage addresses. Wait for it to have 6 confirmations. Then we can try to spend that fund by doing the following:
Get unspent output from your cold-storage address: https://blockchain.info/unspent?address=[4] Copy the output into a text file, leave it on your windows machine. Linux copy will be able to read this file.
Boot back into linux on your pendrive. Use saved brainwallet.org website to sign that transaction (use tab Transaction) by pasting the private key of the address (get from Armory, without space) and the unspent output. Sign the message. Then save the output to the same txt file.
Boot back into your main OS. Paste that signed output to http://blockchain.info/pushtx[5] and push it. You're good to go. You spent your fund in your cold storage.
Now, move everything you have from your online storage there.
submitted by BitCoinWarrior to Bitcoin [link] [comments]

Is there any utility that lets you convert private key from "5" (wif format) to "L" (compressed key) for Linux which runs from command line.

I would be glad to have any solution Python, Perl, Bash or any application written for Linux. Because I need to convert the Bitcoin addresses from vanitygen into Bitcoin-Qt compatible format.
I don't need such options which presume installing heavy wallets like Armory, Electrum, etc, because they presume importing addresses into their address book which won't let me be flexible enough with scripts and huge volume of private keys/public keys.
Even though I appreciate if someone could help with these, it feels very ridiculous to me that bitcoin is so immature that very often I can't find necessary tools for many programming tasks in Linux automation and the whole thing with signing transactions in an automated way is so complicated! It shouldn't be like that. Linux is the most essential tool for developer but currently awesome libs like python-bitcoinlib written by Peter Todd are available only for people who know Python, which is really disappointing, because it create barriers for me since I'm not a programmer even though I know Linux/Bash/PHP
submitted by XfsMonsta to Bitcoin [link] [comments]

The next big thing - THE NEW INTERNET

FreeSpeechMe-SPECIFIC IMPROVEMENTS WE PLAN TO DO:
Hide nmcontrol/namecoind windows on Windows
GNU/Linux users don't see the terminal windows for backend software; Windows users shouldn't be bothered by them either.
Don't try to visit .bit websites when blockchain isn't downloaded
Right now, visiting a .bit website with an incomplete blockchain will use an older version of that name's data. Usually this results in a failure to load the page with no good explanation of what's wrong, but in certain rare cases it could also hypothetically result in security issues such as hijacking. A better version of FreeSpeechMe should refuse to use incomplete blockchains.
Facilitate non-Firefox usage
FreeSpeechMe uses a networking method, HTTP, which is specific to website traffic. Replacing it with a different method, SOCKS, would make it much more flexible, so you could use Dot-Bit for non-website Internet applications such as SSH. It should also be possible to route other web browsers such as Chromium through FreeSpeechMe. FreeSpeechMe should support being installed as a standalone application for users who don't use Firefox (although obviously Firefox will remain the main method of installation).
Improvements for anonymous browsing
Right now FreeSpeechMe supports routing its traffic through anonymization proxies such as Tor and I2P (if they are installed), but it is not compatible with TorBrowser, so while attackers generally can't see your location or IP address, they can deduce that different activities you do online may have come from the same person. FreeSpeechMe should be improved to function in TorBrowser, which would prevent linkage of different online activities.
Improvements for anonymous hosting
FreeSpeechMe supports Tor and I2P hidden services (if the user has Tor or I2P installed), but does not support Freenet, OnionCat, GarliCat, or other anonymous hosting networks. This should be improved.
Support for next-gen TLS specification
FreeSpeechMe is using a method of specifying certificates to prevent hijacking which is deprecated in the Dot-Bit specification. While this method remains very secure, the newer specification has more features, and FreeSpeechMe should implement it.
HTTPS enforcement
Websites which claim to support HTTPS in their domain record should automatically be loaded in HTTPS, even if the user accidentally forgets the "s", to prevent hijacking in such cases. (Note for geeks: this is like the HSTS specification, but works even for sites you haven't visited before.)
Intelligent Redirecting
Websites that want to support Dot-Bit should be able to do so without changing their server configuration, and instead have FreeSpeechMe make the server think the preexisting domain is being requested. The user would still see the Dot-Bit URL in Firefox, and unlike iframe-based methods, the URL displayed in Firefox would change accordingly as the user clicks links..
Fix HTTP protocol bugs
Unencrypted HTTP Dot-Bit websites occasionally have odd behavior in FreeSpeechMe (sometimes manifesting as links not working properly); this is most frequently seen in WordPress websites. While we strongly encourage the use of HTTPS (which isn't subject to these bugs), we still want to fix the bugs with HTTP websites.
Round-Robin Load Balancing
Some large websites use multiple server IP addresses for a single domain. FreeSpeechMe should be able to randomly choose one.
OTHER NAMECOIN SOFTWARE IMPROVEMENTS
Some of this is possibly out of the scope of this one Indiegogo campaign, depending on funds raised. But these are things we're very interested in helping implement:
Rebase on the latest Bitcoin code
Namecoin is based on an outdated version of Bitcoin (0.3.x). We should rebase on a current release. We inquired with a well-qualified and well-respected contractor (who developed Namecoin-Qt) about how much this rebase would cost; the estimate was around $17,000-$35,000 US. Spending that much on one project would be out of the realm of this first campaign. However, it may be possible to reduce this cost significantly by rebasing on a codebase other than Bitcoin, such as libcoin.
Improve scalability
Namecoin currently requires having the entire blockchain for good security. While the 1.6GB blockchain isn't a large concern right now, future scalability requires that clients be able to securely resolve names without possessing the blockchain. There is a proposal for this called SPV+UTXO.
Automatic renewal of names
Losing your names because you forgot to renew them is a problem.
Names should be able to be renewed automatically. Preferably without decrypting the wallet each time the name is renewed, and maybe without even needing your client to be open when it renews. Any solution must be trust-free.
Cold storage of Namecoin name keys
To update a Namecoin name, the keys must be decrypted on a computer with Internet access; this could be a security risk if malware is installed on that computer. To fix this, cold storage should be used, as is possible with Bitcoin.
This is in two parts: (1) port the Armory client to Namecoin (this allows transactions to be signed offline), and (2) allow a cold-storage name to be used as a revocation key for a hot-wallet name (this is called the "import" field).
Optimize Speed
Dot-Bit is already much faster than other top-level domains for both name lookup and name propagation. However, it can be made even faster.
We estimate that pre-cached name lookup time can be decreased by 2- to 5-fold in some cases, uncached name lookup time can be decreased significantly, name update propagation can be reduced from 40 minutes to under 1 minute, and blockchain sync time can be reduced significantly.
Android support
Namecoin software currently does not support Android; this situation should be improved.
Better blockchain anonymity
Like Bitcoin, Namecoin can keep the location and IP address of name owners anonymous (if used with Tor), but the various activities of name owners can be linked by an attacker. This should be improved, e.g. by implementing Zerocoin.
Better blockchain privacy
Some name owners may wish their records to not be publicly accessible; encryption would improve this situation.
Decentralized website single sign-on
Namecoin can be used to log into websites in a secure way without needing a password (protecting people from database leaks or cracked passwords without trusting a third party such as "all your data are belong to us" systems like Facebook); this is implemented as the NameID library by domob. Unfortunately, this library is not easy for non-programmers to integrate with existing websites. Plugins should be created for major website backends such as Drupal, phpBB, WordPress, and SMF, to allow trust-free NameID sign-on to be as easy as checking a box.
Automated builds
Namecoin software should support automated builds and testing so that our developers and testers can work more efficiently. The builds should also be deterministic (as Bitcoin and Tor are doing) to improve security.
Offline signing of static websites
Verifying signatures of static websites against the blockchain would prevent hijacking even if a web server is completely compromised.
SSH client integration
Log into your servers remotely without trusting your network or manually verifying fingerprints, using the same anti-hijacking features that FreeSpeechMe first implemented.
submitted by kitthecar to Bitcoin [link] [comments]

How can I export encrypted private keys from my cold wallet that are easy to import?

I set up a cold wallet using the reference client on an offline machine. All of the sites I read recommended simply backing up the encrypted wallet.dat file, which I did. I did a test run with 0.01 BTC and tried to recover it and it was a nightmare.
I have to do crazy things to restore using the bitcoin-qt or bitcoind client (i.e. move my old wallet.dat, then copy that one over and re-index, which on my old laptop takes literally days).
I then tried using pywallet with the correct passphrase. It dumps a thousand lines of crap along with some "Wallet data not recognized:" errors, and I assumed it wasn't working. I opened it in an editor and cut all the error lines out, and finally got it to import into blockchain.info that way, but it had 300 addresses, even though only 1 was ever used. I suppose this was my fault, I had no idea the default wallet.dat would contain so many addresses (this was all from the offline wallet that I never made a single transaction from).
What I need is something my mom can do. I'm looking for something like the encrypted backup from blockchain.info which is simple ascii text with a password. My goal is to stick this on a usb drive along with a note explaining what to do and put it in a safe deposit box. It needs to be simple enough for my mom to access if something were to happen to me (she's reasonably computer literate, but isn't going to be going and digging around moving hidden files from place to place on her computer). I'd also like the key to be encrypted so that I can make a few copies of the USB key and leave them various places. In the safe deposit box I'll also include a scrap of paper with the password, but otherwise I'll just remember the password so I can recover the coins myself in case the offline computer I'm using craps out.
Any suggestions? Sorry for the semi-rant. I really wouldn't consider myself a beginner, this is just the kind of absurdly difficult thing that scares people away. I suppose I could have used armory or something like that, but I want to understand what I'm doing and not trust any app provided by a company to do my backups.
submitted by bradfordmaster to BitcoinBeginners [link] [comments]

Armory 0.90 keeps crashing in Ubuntu 13.10

Armory had been working fine for me up until a week ago when it crashed while loading up. I restarted it and had to close the Bitcoin-QT process in the background, Armory then appears to be loading until it gets to the scanning database part, then the GUI goes dark (like it does when the system is running out of memory) before the program disappears. When I restart it I have to go through the same process again.
On the Armory site it said to try deleting the database folder from /home//.armory - I done this and now all that happens is the program crashes even sooner, about 3% into building database.
Any help would be greatly appreciated! I do have a paper backup, so I'm guessing I just have to uninstall the program and then reinstall and import wallet?
submitted by ArmoryQuestion to BitcoinWallet [link] [comments]

Consensus on Blockchain.info wallet security?

A while ago I encountered some posts like these:
Just lost 160 BTC from address managed with blockchain.info MyWallet
A brief analysis of the security of Blockchain.info's web-based wallet service.
Blockchain.info lost 45 BTC instantly
Large number of blockchain.info wallets stolen from?
...and, being paranoid, I moved my coins to Armory to have time to investigate the security of Blockchain.info's My Wallet.
What are everyone's current thoughts on the security of My Wallet? At the time I used it, it seemed like the best web-based (hybrid) wallet out there. I was using the Chrome extension (so locally-hosted javascript), and I was using 2-Factor Authentication.
While I understand that Armory gives me an unprecedented level of security, it's not the most convenient. I don't like having to wait several minutes to sync Bitcoin-Qt every time I use it. I also really like the Blockchain interface. My only gripe is Blockchain not having deterministic wallets.
It seems to me like a lot of the issues with lost coins in those posts above were in fact user error. I think at least one had to do with Blockchain sweeping coins into an insecure address, which someone shouldn't have imported into their wallet.
I'd like to go back to using Blockchain, but if it's widely considered to be insecure, I'll stay away.
submitted by Juggernaut74 to Bitcoin [link] [comments]

Are we overlooking pgp verification of wallet installation files?

I am curious how many people use pgp to verify the new version of their favorite wallet software every time a new version comes out? To me it seems like pgp verification isn't taken very seriously. Most, but not all vendors will put out new pgp signature files with each new release however if you are relatively unaware of security this could mean you are unknowingly missing a very important step. Importing the authors pgp key, downloading the associated signature file and then verifying the executable isn't very obvious to those who aren't security savvy. However it is an obvious security hole and a potential honeypot for anyone looking for some easy coin. One thing I find disturbing is how few of the major wallet developers put any significant effort into educating their users on the first step of securing their hot wallet. Multibit and armory are the only two clients I know of that give any information on pgp verification, but even multibit misses this important step on their "How to install" page. Electrum doesn't even provide a signature file for their linux version instead providing a hyperlink with an md5 hash appended to it. Bitcoin-qt from what I can tell only provides sha256 hashes of their files with zero instruction on how to use them. To me it seems like the pgp step of securing a wallet is looked at as the boring minor tidbit that you have to have that nobody really wants to put time into resulting in most vendors throwing up some hashes/signatures with little to no information on how to use them. I think that all vendors should have a section with instructions on how to verify their software, put this as the second step in getting started with their software right after the download step and make sure to provide pgp signatures for each installer package and not just hashes. For me, not being a security expert, I feel much safer verifying a pgp signature vs checking that a hash matches. With bitcoins being targeted on a daily basis through incredibly creative means this seems to me like a giant gaping hole that could be fought with a very small amount of education. Just a thought.
Edit: because I suck at the grammar Edit: after digging around I found the electrum signature files for linux. There is no direct link to the page from their website but they can be found here: http://download.electrum.org/
submitted by bitmagi to Bitcoin [link] [comments]

Step-by-step guide on how to recover your Bitcoin Wallet using Armory

I deal with the finances for the family so I maintain a how to guide for our finances in case something were to happen to me. Here is my latest chapter on how to recover our Bitcoin holdings. I hope others might find it useful but maybe it will save you some time.
Overview of steps: 1) Install Bitcoin-Qt app 2) Install Amory app 3) Import Paper Backup
What you need: 1. Bitcoin-Qt app. This is free software downloadable from http://www.bitcoin.org 2. Amory - Bitcoin Wallet Management software. This is also free software available for download from https://bitcoinarmory.com/ 3. The Paper Wallet from our super-secret hiding place
Detailed Steps 1. Download the Bitcoin-Qt app from www.bitcoin.org. Install and run Bitcoin-Qt on an internet connected computer.
  1. Wait for Bitcoin-Qt to synchronize with the network. This will take a painfully long time the first time (potentially 24 hours!), but it should only be a few minutes on subsequent loads. You will see a green checkmark in bottom-right corner of Bitcoin-Qt when it is ready. NOTE: During this time, the wallet needs to validate the blockchain. Validating the blockchain takes a long time (24 hours). The blockchain is a record of all transactions and identifies the owner of the Bitcoin.
  2. Download the Armory Wallet Management software from www.bitcoinarmory.com. Install Armory, but don’t run it until Bitcoin-Qt is synchronized.
  3. Start Armory!
  4. Armory will prompt you asking if you want to create a New Wallet or Import Wallet. Select Import Wallet and then select, Restore from paper backup. Enter the codes from the paper backup into Armory application. And voila, our wallet will be restored. NOTE: Put the paper backup back in its hiding place.
submitted by Bonesman to Bitcoin [link] [comments]

How to double spend in order to cancel unconfirmed transaction?

Hey guys
Ive been trying to research a solution to this but havn't found anything:
I sent myself a bunch of bitcoin today via blockchain.info thats been sitting in unconfirmed status all day since i forgot to attach a fee. I sent .0625BTC.
Ive been watching it all day and my queue has been anywhere between 3-8 hours, fluctuating up an down with no progress.
I know there was once a way to cause a double spend transaction by importing a wallet into bitcoin software like BitcoinQT and re-doing the transaction so the new one gets picked up instead, but it seems like the newer versions all take into consideration the "Spendable balance" which knows the money isnt there.
Anyone have a way I can do this?
Maybe some steps to do it in Brainwallet?
Here it is... still sitting there https://blockchain.info/tx/f3f058e1b91e0f345ff46bad72e80d62bb78ab4c6cc5d734a8f94606e26b7c49
EDIT: It looks like Armory may now have this function as linked in the FAQ https://bitcoinarmory.com/download/troubleshooting/
submitted by Drogean to BitcoinBeginners [link] [comments]

Clearing up some misconceptions about full nodes | Chris Belcher | Feb 10 2016

Chris Belcher on Feb 10 2016:
I've been asked to post this to this mailing list too. 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 and similar sites: https://bitnodes.21.co/
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 as in:
https://bitcoin.org/en/release/v0.11.0#block-file-pruning. In Bitcoin
Core 0.12, pruning being enabled will leave the wallet enabled.
Altogether this should require less than 1.5GB 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
found in https://bitcoin.org/en/full-node#reduce-traffic . 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
(https://bitcoin.org/en/release/v0.10.0#faster-synchronization) and
libsecp256k1 have greatly improved the initial synchronization time.
It can be further improved by setting -dbcache=6000 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
(See
https://github.com/bitcoin/bitcoin/pull/6954#issuecomment-154993958)
Note that you'll need Bitcoin Core 0.12 or later to get all these
efficiency improvements.
=== 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.
(https://bitcoinarmory.com/) or JoinMarket
(https://github.com/AdamISZ/JMBinary/#jmbinary)
Multibit connecting only to your node running at home, Electrum
connecting only to your own Electrum server)
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.
original: http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-February/012435.html
submitted by dev_list_bot to bitcoin_devlist [link] [comments]

Restore Wallet How To Install, Backup And Restore A Litecoin Wallet How to import bitcoin paper wallets to your client DIY Bitcoin Armory Hardware Wallet (Teaser) Bitcoin Cash: Step By Step Guide To Claim Your Free BCC / BCH

Thanks for the info but I'm just gonna transfer the money. I'm not happy with Armory for the following reasons: 1) dependency on Bitcoin-Qt 2) Poor UX (eg: after sending money I have to wait for two screen changes and a potential popup before the transaction is done and none of this is messaged to the user) 3) Constant crashes 4) Bad update system (I was repeatedly prompted to update to 93 Open Bitcoin Armory (testnet), navigate to the settings panel, and deselect “Let Armory run Bitcoin-Qt/bitcoind in the background.” Next, navigate to the location of your Bitcoin Core installation, for example C:\Program Files\Bitcoin. Once there, it is easiest to click on the “bitcoin-qt” application and create a shortcut. You can then take those private keys and import them into other wallet software.IMPORT BITCOIN QT WALLET TO ARMORY Bitcoin Armory Import Wallet Dat. Bitcoin armory wallet location; The short answer is that the Bitcoin network requires fees for certain types of transactions to prevent spamming and “Denial of Service” (DoS) attacks. To verify in Linux, “cd” to the directory containing the installer (usually Downloads), download and import the Armory signing key from the ubuntu key-server, install the signature verification program, and then use it verify the signatures on the *.deb files: `$ cd Downloads # the directory containing the *.deb $ gpg --recv-keys Run Bitcoin-Core; Select Help (to the right of Settings); Select Debug of you looking to import your Vanity address into your BitCoin QTThe wallet is encrypted, but I remember the password. How To Import Wallet Into Bitcoin Qt Brave Ethereum. In various conversions such as Base58, Bitcoin-QT (Bitcore), Base64,.

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Restore Wallet

Armory 15,460 views. 5:13. Bitcoin How to import your old wallet into new one tutorial works 100% Recovered 1.7 BTC - Duration: 8:26. XOOMdotWS 9,682 views. 8:26. Armory 16,815 views. ... LithiumSolar Recommended for you. 33:01. Litecoin-QT wallet Private Key access tutorial. Client dumpprivkey ... Getting your Private Keys from the Bitcoin Core wallet ... Bitconnect Coin Community member teaches users how to set up and sync a new BCC wallet. Welcome back Crypto Friends, it’s been quite some time since I made a video. I want to talk about a couple ... If you have a Bitcoin QT wallet you need to export your Private Key and Import it into the Bitcoin ABC QT wallet. The Bitcoin ABC QT wallet is currently working fine - I can see my Bitcoin Cash ... I used Armory wallet to import my mini private keys but the process should be similar with other wallets that supports importing mini private key. This video is also available in English: https ...

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