Does anyone have insight into how Coinbase calculates the number of confirmations for a transaction?

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

Code example, in Ruby:

#!/usr/bin/env ruby require "open-uri" require "json" # call this script with `ruby block_height.rb ` tx = ARGV.shift puts "Getting info for #{tx}..." j = JSON.parse open("http://blockchain.info/rawtx/#{tx}").read if j["block_height"] b = JSON.parse open("http://blockchain.info/latestblock").read puts "%d confirmations" % (b["height"] - j["block_height"] + 1) else time_since = Time.now.gmtime.to_i - j["time"] puts "It's been #{time_since} seconds since the transaction was created." puts "It's not been ten minutes yet!" if time_since < 600 puts "It's due any time now." if time_since >= 600 end

Calculating the transaction fee is best...

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With the recent rally in the bitcoin price, there has understandably been a large increase in the amount of users and transactions. This is pushing the already congested bitcoin network to its limits, as the blocks do not have enough room for all the transactions.

This means that your transactions may stay in the Pending state for longer than normal as they wait to be picked up and confirmed on the blockchain.

How to Tell if Your Transaction is Affected

In your transaction history for your Coinbase wallet, click on the pending transaction that you want to check.

In the window which appears, note the number of confirmations that your transaction has received on the blockchain.

If your transaction has already been broadcast to the network (for outgoing Tx), you can click this "# confirmations" link to see your transaction on a blockchain explorer:

If your transaction is already on the blockchain but is waiting for...

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Last updated: September 22, 2016

1. Basic Coinbase Services.

1.1. Eligibility. To be eligible to use the Coinbase Services, you must be at least 13 years old. In order to link a funding method or to purchase or sell digital currency, you must be at least 18 years old (or the applicable age of majority and contractual capacity). If you are under the age of 18 and you wish to engage in digital currency purchase or sale activity, please contact us at support@coinbase.com.

Your eligibility to access certain...

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A nice post for Bitcoin beginners from the Agora Forum explaining the simple logic being the confirmation system of the Bitcoin transactions:

Op can be found here: http://i4rx33ibdndtqayh.onion/index.php/topic,2905.msg30255.html
By Keno13: http://i4rx33ibdndtqayh.onion/index.php?action=profile;u=598

Quote:

There has been a lot of confusion lately about how bitcoins are sent, where they go, and why they haven’t showed up in some peoples wallets in a timely fashion. This is just a quick guide/explanation about the process, to help answer any questions people may have.

Congratulations, you just bought some bitcoins for your dark net purchase! the next step is obviously to get it to your Agora wallet. You put in the wallet address, complete a few security pop ups and hit the send button. Fantastic! Now its time to explain what happens while you’re waiting…

Bitcoin is kind of like a giant game of pass the parcel. Except your parcel is a giant wad...

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Last updated: 20th March 2015

Bitcoin transactions are sent from and to electronic bitcoin wallets, and are digitally signed for security. Everyone on the network knows about a transaction, and the history of a transaction can be traced back to the point where the bitcoins were produced.

Holding onto bitcoins is great if you’re a speculator waiting for the price to go up, but the whole point of this currency is to spend it, right? So, when spending bitcoins, how do transactions work?

There are no bitcoins, only records of bitcoin transactions

Here’s the funny thing about bitcoins: they don’t exist anywhere, even on a hard drive. We talk about someone having bitcoins, but when you look at a particular bitcoin address, there are no digital bitcoins held in it, in the same way that you might hold pounds or dollars in a bank account. You cannot point to a physical object, or even a digital file, and say “this is a bitcoin”.

Instead, there are only...

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FAQ

The purpose of this FAQ is to give general education and information about Bitcoin. It should not be considered financial advice.

The great thing about Bitcoin is that you do not need to understand how it works in order to use it. If you are interested in diving in a little deeper, this FAQ is for you.

Q: What is Bitcoin?

Put very simply it is a new form of money that works extremely well on the Internet.

Back to top

Q: So it's a "virtual currency"?

No. Virtual currencies are generally tokens issued by a company for near-exclusive use on their site. Examples include loyalty or gift cards, air miles or mobile phone top-ups.

Bitcoin is a general purpose digital currency. It is programmable money.

Nothing like Bitcoin has ever existed before.

In a similar way that email revolutionised the postal service, Bitcoin can revolutionise financial services.

For a broader view at what Bitcoin provides you should...

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There are three methods one could use to verify a legitimate checking account and if the user is the authorized party to the account.

1) ACH Prenote

The traditional way to verify a checking account is to perform an ACH (Automated Clearing House), Prenote. A Prenote is a zero-dollar transaction that is sent to a bank through the ACH network to verify the accuracy of routing numbers and account numbers and in some cases the name of the account holder. If the account data was incorrect, the Prenote would be rejected and the sender can then reject the account for use as an ACH. The Prenote therefore has limited utility for most use cases and is used generally to verify checking accounts for Payroll receipts. This can also take up to 5 business days.

2) ACH Test Transaction (challenge-response verification)

The problem with a Prenote is that it does not actually verify if the person presenting the bank account is actually authorized to use the account (eg. has...

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Transactions are the most important part of the bitcoin system. Everything else in bitcoin is designed to ensure that transactions can be created, propagated on the network, validated, and finally added to the global ledger of transactions (the blockchain). Transactions are data structures that encode the transfer of value between participants in the bitcoin system. Each transaction is a public entry in bitcoin’s blockchain, the global double-entry bookkeeping ledger.

In this chapter we will examine all the various forms of transactions, what they contain, how to create them, how they are verified, and how they become part of the permanent record of all transactions.

A transaction’s lifecycle starts with the transaction’s creation, also known as origination. The transaction is then signed with one or more signatures indicating the authorization to spend the funds referenced by the transaction. The transaction is then broadcast on the bitcoin network, where each...

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This article explains Bitcoin mining in details, right down to the hex data and network traffic. If you've ever wondered what really happens in Bitcoin mining, you've come to the right place. My previous article,

Bitcoins the hard way

described how I manually created a Bitcoin transaction and sent it into the system. In this article, I show what happens next: how a transaction gets mined into a block.

The purpose of mining

Bitcoin mining is often thought of as the way to create new bitcoins. But that's really just a secondary purpose. The primary importance of mining is to ensure that all participants have a consistent view of the Bitcoin data. Because Bitcoin is a distributed peer-to-peer system, there is no central database that keeps track of who owns bitcoins. Instead, the log of all transactions is distributed across the network.

The main problem with a distributed transaction log is how to avoid inconsistencies that could allow someone to...

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Coinbase allows BTC to become spendable after zero confirmations as long as they are in sync with the BTC blockchain, which they usually lag behind a bit.

The reason Coinbase lags behind the bitcoin blockchain is because their internal node is generally lagging behind the blockchain about 2-4 blocks; sometimes less, sometimes much more. I don't know why, but I imagine it helps reduce fraud with instant buys and maybe the system they use to sync their services with the blockchain gets bogged down under heavy loads..

Coinbase does have a network page (https://coinbase.com/network) that allows one to check the status of the last block seen on their side. Therefore, if it shows "Last block created 57 minutes ago," one can safely assume they are about 5-6 blocks behind the btc blockchain and will take some time to catch up.

It can be quite annoying and cause a purchase to be delayed or cancelled, but by watching the network page, one can make more informed decisions...

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Coinbase has been hit-and-miss for me for the past month. For example I've had: 1 "instant transfer/buy" that took 23 hours for the coins to arrive. The next day, before my original purchase arrived I needed to make a small additional order to compensate for a rate drop and that one went through right away.

More recently I've had outgoing transfers that took a few hours to appear on the blockchain including one that took nearly 24 hrs again.

For the most part they did not respond to support requests until after the issue was resolved. No acknowledgement to tweets @ them.

Eventual support email was the same form letter each time:

Sorry about the delay! We had an issue syncing >with the blockchain which resulted in >unconfirmed transactions that remained in the >pending state for too long. Now these >transactions have been pushed through - let me >know if you still need help with anything. Again, >my apologies for any undue stress this has >caused!

...
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Find answers to recurring questions and myths about Bitcoin.

Table of contents

General

What is Bitcoin?

Bitcoin is a consensus network that enables a new payment system and a completely digital money. It is the first decentralized peer-to-peer payment network that is powered by its users with no central authority or middlemen. From a user perspective, Bitcoin is pretty much like cash for the Internet. Bitcoin can also be seen as the most prominent triple entry bookkeeping system in existence.

Bitcoin is the first implementation of a concept called "cryptocurrency", which was first described in 1998 by Wei Dai on the cypherpunks mailing list, suggesting the idea of a new form of money that uses cryptography to control its creation and transactions, rather than a central authority. The first Bitcoin specification and proof of concept was published in 2009 in a cryptography mailing list by Satoshi Nakamoto. Satoshi left the project in late 2010...

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Since Nakamoto, no one has advanced this space more than Vitalik Buterin, the 22-year-old child-prodigywho in 2013 began thinking of extending blockchain’s capabilities beyond just money, launched his vision in 2015 and saw it explode this year with ETH increasing by more than 700%. More than just a new currency, Vitalik has created a new technology – an ethereum virtual machine that executes smart contracts. In the process, he has transformed money into truly digital code which anyone with some knowledge can program and order around. As such, ethereum is an upgrade of bitcoin itself, which is still waiting for its smart contract functionalities through Rootstock, as well as an upgrade of analogue money. Developers, seeing the new capabilities, flocked, as did ordinary users, investors, household brands, consortiums. A new vibrant ecosystem was born that began to think of Decentralized, Autonomous Organizations, a world of no CEOs, no Board of Directors, where VC investment is open...

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Jeff Garzik, a bitcoin code veteran, offered some insight into his purpose for launching Bloq a code-for-hire service to develop features for blockchain software and provide access to blockchain support. In a podcast interview on Bitcoin Uncensored co-hosted by Chris DeRose, a self-described bitcoin evangelist, Garzik offered his views on the current block size debate and bitcoin’s future.

Jeff Garzik

During the interview, Garzik voiced support for an inclusive approach to resolving the block size and scaling issues, but this inclusiveness has left the dialogue open to misunderstandings about bitcoin and its potential.

Interviewed from China, Garzik talked the state of bitcoin development.

Update On Bloq

Asked what he is doing at Bloq, Garzik said he is building a product, hiring a team, looking to go beyond the beta and have the product released in the next month or two.

There are two key aspects to Bloq, he noted. One is BloqThink, a...

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Set up your first Bitcoin wallet.

If you don't feel technically competent, it's perfectly acceptable to ignore the next few steps and just leave your bitcoin in the account where you bought them. In fact, most bitcoin holders do just that. But the beauty of bitcoin is that it's money that no third party needs to control for you. In addition, since exchanges store hundreds of millions of dollars of bitcoin, they are a very attractive target for hackers. So unlike stuffing dollars in your mattress, it's actually safer to store your bitcoins on your own rather than trusting them to an exchange. All the wallets listed here will not give any third-party access to your bitcoins:

Mobile Wallets are Bitcoin wallets that run on your mobile device. Such wallets are portable and practical for in-store use. Mobile devices tend to be less prone to malicious software than are computers, creating a reasonably secure environment for small amount of bitcoin. Some of the best mobile wallets...
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