How to Clear a Stuck Bitcoin Transaction

World Cash

A Bitcoin transaction can fail to confirm, or become “stuck,” for a number of reasons. Stuck transactions are usually confirmed after several days, but sometimes waiting isn't an option. Fortunately, many stuck transactions can be cleared using nothing more than a Web browser. This article shows how.

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Moving the Bitcoin Core Data Directory

Oversize

Bitcoin Core runs as a full network node and maintains a local copy of the block chain. This data independence improves wallet privacy and security. Unlike some SPV wallets that transmit addresses to peers, Bitcoin Core stores all transactions locally. With local access to the complete set of headers and transactions, Bitcoin Core can use full verification to tell when peers lie about payments.

However, dealing with the block chain comes at a price. An ever-growing data set causes smaller hard drives to fill up quickly. Furthermore, a new wallet can't be used until the full block chain is downloaded and processed, which can take several hours on mid-range equipment.

These problems can be solved by moving and copying Bitcoin Core's data directory. This article describes two approaches that can be used with either a new or existing Bitcoin Core 0.10.0 installation.

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Offline Installation of Armory on Tails and Ubuntu Linux

Keys

Armory supports cold storage through offline transaction signing. This technique allows funds to be spent without exposing private keys to network-based attacks. Offline signing requires two computer systems - one with an Internet connection, and one without.

Installing Armory on an Internet-connected computer is relatively easy, but installation on an offline computer is much more difficult. The problem comes down to dependencies; online computers can automatically download them, but offline computers must be given dependencies as files on a removable medium. Armory offers an offline bundle designed to simplify the process of offline installation on Ubuntu 12.04. However, some users, including myself, ran into problems using it. Moreover, some situations call for installing Armory on other Linux systems.

What's needed is a simple procedure for creating an Armory offline bundle on arbitrary Linux systems. This article gives procedures for Ubuntu 14.04 and Tails 1.3.

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Blockchain.info Paper Backup Stores Private Keys in the Browser History

The first step in using any Bitcoin wallet should be to create a backup and store it securely. A Blockchain.info Web wallet supports backups through its Paper Backup feature. Use of this feature was found to store an unencrypted copy of the wallet’s private keys in the browser history. This unencrypted backup survived browser and system restarts. The first disclosures of this behavior appear to have been made more than six months ago on Bitcointalk and the Bitcoin subreddit.

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Opening Bitcoin URIs on Mac OS X

Put Payments Here

Wouldn't it be nice if making a Bitcoin payment were as easy as clicking on a link? In principle, this is already supported with Bitcoin URIs. Clicking a Bitcoin URI should launch a preferred wallet, pre-populating a payment transaction with data pulled from the link. Clicking one button would approve the transaction. Copying addresses or payment amounts would be unnecessary.

In practice, support for Bitcoin URIs by software wallets has been patchy at best, particularly on OS X. This article describes a solution that can be immediately implemented by any Mac owner using any downloadable wallet.

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Who Needs Bitcoin Change Addresses Anyway?

Coin Jar

Few topics in Bitcoin cause more confusion, anxiety, and loss of money than change addresses. They seem counterintuitive and unnecessary. They're a major contributor to wallet software complexity. When used improperly, they can de-anonymize not just the payer but other parties as well.

Given the many problems with change addresses, why do they exist in the first place? This article explains what change addresses are, why they're essential to Bitcoin, and how to protect your money and privacy.

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Installing Bitcoin Core on Ubuntu

Ubuntu is often recommended as an alternative to Windows for running Bitcoin Core. Recent reports of a false postive virus signature in the block chain and an inappropriate response by Microsoft antivirus software reinforce this point. This guide shows how to install and run Bitcoin Core on a clean Ubuntu 14.04 system.

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Making Sense of Bitcoin Transaction Fees

Electric Company

Every Bitcoin transaction is subject to a fee paid by the sender. In contrast to bank fees charged at either a flat rate or as a percentage of transaction value, Bitcoin fees are based on the amount of data needed for encoding. Understanding this system is not difficult, but its nuances and non-intuitive nature confuse many Bitcoin users, new and experienced alike.

Understanding transaction fees can save you both money and time. This guide describes how the Bitcoin transaction fee system works and how to use it effectively.

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Six Things Bitcoin Users Should Know about Private Keys

Keys

Private keys have been an integral component of Bitcoin since its first description in 2008. Wallet software generally protects users from the need to understand what private keys are and how they work. Even so, most users eventually come face to face with private keys, too often with unpleasant results.

A basic understanding of private keys helps prevent loss of funds and other mishaps, but it can also offer useful insights into how Bitcoin works. This guide outlines the most important private key concepts for effectively using Bitcoin.

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How to Spend a Bitcoin Paper Wallet in Three Easy Steps

Paper Wallets

Have you received a Bitcoin paper wallet, possibly as a gift, tip, prize, or through a Kiosk? Are you wondering how to spend the money contained on this paper wallet? Spending funds from a paper wallet is a three-step process that can be done by anyone with a Web browser and an Internet connection. This guide shows how.

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Bitcoin Paper Wallets from Scratch

Paper Wallets

Bitcoin paper wallets offer a useful solution to the problem of storing funds for later use. However, the ease with which paper wallets can be generated tends to obscure important technical and security considerations that may only become apparent at a later point. This article introduces paper wallets from the beginning, with an eye toward using them for secure, long-term, offline storage.

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A Gentle Introduction to Bitcoin Cold Storage

Winter

Imagine opening your Bitcoin wallet. To your surprise, it‘s empty and there’s no way to recover the money you lost. How do you feel?

Every Bitcoin user faces the problem of securely storing their money. Unlike the banking system, there‘s little recourse when things go wrong, and little margin for error. Thefts and losses can be prevented, but they can’t be rolled back. Preventing these losses is the goal of cold storage.

Cold storage is an important subject with a steep learning curve. To make the topic more approachable, this article introduces core Bitcoin concepts when needed. It concludes by discussing a new Bitcoin feature that could simplify the safe storage of funds.

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Five Ways to Lose Money with Bitcoin Change Addresses

Cash Register

Bitcoin can be coldly unforgiving of mistakes, and nowhere is this better demonstrated than with change addresses. Although change addresses provide a key privacy tool, they can also lead to confusion, loss, or theft when not understood.

This article explains how to safely use one of Bitcoin's least understood features. It ends with a list of common pitfalls and ways to avoid them.

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A Complete Guide to the MultiBit Bitcoin Wallet

MultiBit

MultiBit is a popular Bitcoin wallet program that aims to combine fast startup times, a simplified feature set, and support for multiple languages.

This guide documents MultiBit through step-by-step examples written from the perspective of a reader new to both MultiBit and Bitcoin. Having access to a small amount of bitcoin will make the examples presented here easier to understand. Many purchase options are available; U.S. residents can even pay for bitcoin with cash at a bank teller.

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A Beginner's Guide to the Electrum Bitcoin Wallet

Electrum Logo

Electrum is a Bitcoin wallet built for speed and convenience. A streamlined design and rich feature set make this software a popular choice for beginners and experts alike.

This guide introduces Electrum with step-by-step examples highlighting the most important features. It is intended for Bitcoin and Electrum beginners - little previous experience with either is needed. Owning some bitcoin will make the examples much clearer and is encouraged.

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