Review: Coinkite Opendime Bitcoin Hardware Wallet ...

[dev] Transaction Malleability Strikes Back

Okay, the headline's over dramatic, but "Transaction Malleability is a bit inconvenient" is less catchy. As you may be aware, there's an ongoing transaction malleability attack against Bitcoin at the moment. Due to how the signatures on transactions work, there are two different valid values for one of the variables (S), and these can be calculated from each other. Someone is switching these values over in relayed transactions; the result is an entirely valid transaction, but as it's constructed differently, it has a different transaction ID (which is the SHA256 hash of the serialised transaction).
I've just gone over half the audiences' heads haven't I?
Bad people are being silly with Bitcoin transactions and making it hard to identify transactions.
How does this relate to Dogecoin, I hear you ask? Well, in a number of ways:
  1. There's a similar issue in Bitcoin Core 0.9 and below (which Dogecoin Core 1.8 is based on), about how signatures are stored (DER signature format for those who want technical details), which Dogecoin Core 1.10 fixes, so mostly I'm using this to motivate people to upgrade once we hit release.
  2. The same issue is in Dogecoin Core, including 1.10. That means we'll need to remove it at some point, although that's not trivial. There is a Bitcoin standard (BIP 62) for dealing with this, but it's not been enabled (I believe issues with unusual but valid transactions being broken).
  3. I've been spending bits of this week finishing off adding support for BIP 66 (the DER signature format fix) for bitcoinj. The main bulk of that has been submitted and is awaiting review, although it's not actually enabled yet. This also introduces a lot of architecture needed for other transaction malleability fixes.
  4. If you've ever heard me say we can't use CATE yet because of transaction malleability, this is what I mean!
Obvious question, what does this mean for the average shibe, and what do you need to do? Well, generally it shouldn't really have a lot of impact, however if you're sending a transaction on the Bitcoin block chain, don't presume the transaction ID it's sent with is the final one. All block explorers I'm aware of let you search by address, which you should use instead. Once a transaction is mined it will be "locked in" and can't change, but until then (i.e. until the first confirmation) it can change ID. I'll let you know as I see more developments.
The other big activity going on has been the resurrection of Dogeparty. patricklodder has added a mirror of the Dogeparty wallet with funding from sporklin, go hug them both if you're a Dogeparty user! coinwarp is working on an updated version of Dogeparty based on a more recent version of Counterparty, which brings me to what I've done with the other half of the week.
Recent versions of Counterparty depend on a feature called "searchrawtransactions" which was submitted to Bitcoin Core but never merged. As such, it's not part of Dogecoin Core 1.10, so I've been dusting that work off and updating it. I have a basic patch done (, but this close to release it will probably not make it into 1.10 itself, and instead I'll do a separate client with the extension. I'll also raise it as a pull requests against Bitcoin Core, and see if we can get it into their code, so maintenance happens above us :-D
1.10 remains in a stabilisation state, I'm expecting we'll have a release candidate later this month. bitcoinj work is primarily waiting on Mike being available to review code (and he's tied up with the Bitcoin block size debacle of course), there's minor improvements going on to libdohj and python-altcoinlib. Think that covers everything!
Updates should be back on schedule from here on, so expect the next on the 18th.
Have a great fortnight everyshibe!
submitted by rnicoll to dogecoin [link] [comments]

More information on the Renewable Energy consumption of Bitcoin and the environmentally friendly alternative BlackCoin TL:DR

The amount of electricity required to maintain Bitcoin’s security is legendary. Its miners are scouring the globe searching for areas with the least-expensive electricity rates.
Unfortunately, these areas are where the least expensive renewable-energy resources exist in the world.
Links are provided below to the references to back up the claims made here. This document will be updated as needed based on your comments below.
It has been estimated that the additional electricity required to maintain BlackCoin’s cooperative minting network is much less than three one-thousands ( 3 / 1000 ) of what is now used to run an equivalent sized competitive Bitcoin mining network. Bitcoin’s current electrical consumption equipment arms race is gobbling up irreplaceable, renewable-energy resources in areas where they provide the less expensive renewable energy options bar none.
A recent study cited in the Wall Street Journal shows that the hash rate required for Bitcoin’s security last fall was one one-sixtieth (1 / 60) of what it is now. This hash rate inflation has been fueled by the tremendous profitability of large scale corporate mining operations, which have produced the mining technology arms race.
The largest known corporate Bitcoin mining operation is reported to be housed in a warehouse in Central Washington State where it takes advantage of the US’s lowest electricity rates bar none. The Spokane Review recently reported that a handful of additional competitors are now about to pop up.
Washington State is the leader in hydroelectric generation with 29% of the total national capacity according to the US Energy Information Administration. It is 10th in wind energy production. Nevertheless, the whole state still has the lowest residential electric rates in the country.
The New York Times reported on a similar setup in Iceland, which may have the least expensive electricity of any country in the world. It is powered by hydro and geothermal resources.
These corporate mining operations compete against each other for the right to enter the next ledger page into the Bitcoin blockchain. The startups that produce the otherwise useless mining equipment are forced to make outrageous claims for their latest drawing board designs to get preorder payments to finance their production as has been well documented by CoinDesk in numerous articles.
Are we about to repeat the environmental disasters that followed the 1849 California Gold Rush and the wildcatting boom that began with the Spindletop oil gusher? This trend will continue as long as the Bitcoin mining technology continues to improve at breakneck speed driven by the profitability resulting from the squandering of these irreplaceable resources.
It took three and a half years after Satoshi Nakamoto launched Bitcoin in January 2009 before Sunny King in August 2012 to launch Peercoin, the first environmentally friendly cryptocurrency. However, Peercoin is designed to be the savings account complementing the best environmentally friendly checking account cryptocurrency. The market has been trying since then to settle on the best environmentally friendly challenger for Bitcoin.
The Russian crypto developer rat4 launched BlackCoin on February 24, 2014 at 6:00 UTC after making the customary announcement on February 16 on the Bitcoin Forum. Startup crypto exchange Mintpal quickly recognized the potential of rat4’s improvement of the design of the innovative Mintcoin protocol.
This helped catapult BlackCoin into 19th place in market cap by the start of April. BlackCoin obtained its current 10 th place position after Coinkite chose Blackcoin to add to its terminals in June joining Bitcoin and Litecoin.
Sunny King’s protocol has now been tested on many environmentally friendly alternatives. The market has now chosen BlackCoin to be checking account to Peercoin’s saving account.
The Bitcoin MIT Project will provision every undergraduate at that institution with $100 worth of bitcoins in the fall semester as an experiment. The proposed BlackCoin MIT Airdrop is currently being discussed by the Blackcoin Community on its reddit page. The proposal calls for provisioning each MIT graduate student with $100 of the best environmentally friendly alternative to Bitcoin in the best technology crucible in the world.
It appears from the MIT announcement that the MIT Kerberos & Internet Trust Consortium may have been used as the vehicle for obtaining tax exempt fiat donations. Therefore, should the newly formed BlackCoin Foundation ask the Trust to set up a donation account and let the environmental community try to raise the less than $1 million required to fund the MIT Airdrop.
If you have arrived here from somewhere else and are interested in learning more about BlackCoin and the MIT BlackCoin Project, please join the discussion with us at the BlackCoin subreddit:
Please report proofreading and editing corrections in comments below. References
Electricity requirement calculations needed to maintain the BlackCoin network
Wall Street Journal Article on Bitcoin hash rate
Spokane Review Article
US Energy Information Administration – Washington State Renewable Energy Report
NT Times Iceland Bitcoin mining article
CoinDesk mining equipment articles
Bitcoin MIT Project article that mentions MIT Kerberos & Internet Trust Consortium
submitted by RJSchex to blackcoin [link] [comments]

Proposed PR Newswire press release

Proposed PR Newswire press release I initially proposed on the sticky thread at the link below that we produce a press release. Bigbtcconsulting later agreed to work on this. Iconic agreed to use his PR Newswire account to handle our blackcoin press releases, if we reimburse him. Here is that thread: I produced the first rough draft and pasted it on the thread at the link below. Iamtheshirt later pasted a revised version, which I think is a big improvement. I used MS Word’s Track Changes feature to produce the version below based on Shirt’s revision. TL:DR I will be placing a clean copy of my revise version in a post below as soon as I have produced it. Anyone can suggest changes or produce a revised version. Blackcoin: Bitcoin's Green, Decentralized Competition Blackcoin vaulted onto many investors’ radar screens two weeks ago when its market cap increased ten time in 24 hoursthe value of the cryptocurrency multiplied ten times in 24 hours. At the peak of this meteoric rise, Blackcoin had the sixth-largest market cap of all cryptocurrencies. In the following day, the unsustainable growth rate caused a sell-off that dropped Blackcoin's value sharply. From that low point, Blackcoin has seen more sustainable growth over the last week, regaining almost 400% in value and market cap. Blackcoin is currently the ninth-largest cryptocurrency by market cap. At the time of this publication, each Blackcoin is valued at 0.19 24 USD. So, what is different about the two month old Blackcoin that to warrant the large amount of attention it has received? Blackcoin was specifically designed to improve upon two of the Bitcoin protocol by mitigating two of Bitcoin's most widely criticized design flaws: 1. The tremendously expensive and energy-inefficient proof of work system used to run the Bitcoin network and minet new Bitcoins has been replaced by Blackcoin's 100% proof of stake system. The capital equipment cost and electrical consumption required to maintain a Blackcoin network the size of Bitcion’s will probably be about a humdred times less. be By percentage of market cap, the operation cost and electricity usage of the Blackcoin network is merely a small fraction of the costs necessary to maintain the Bitcoin network. 2. Bitcoin’s ten minute ledger block generation time has been reduced to 10 seconds with Blackcoin. replaced by Blackcoin’s ten second block generation time. Since all transactions on cryptocurrency networks are contained in these ledger blocks and limited by their speed, Blackcoin has a clear advantage in merchant adoption over Bitcoin for point of sale transactions or any form of transaction in which speed is critical. Blackcoin's 100% proof of stake network is supported by stakeholders all over the world who receive by offering 1% yearly interest on their stake as an incentive to run the wallet software, thereby securing the network. Unlike the proof of work system, the proof of stake system does not require unnecessary, very-energy- intensive large calculations by competing miners in order to secure the network. This is the primary reason for Blackoin's fast transaction speed. The proof of stake system also ensures that the network will continue to run in perpetuity without requiring the use of prohibitively –expensive, energy-hungry specialized equipment, making Blackcoin's network extremely cost and energy efficient. Bitcoin's Proof of Work system was supported by individual computers in the past, but because the system requires large calculations by competing miners in order to secure the network and minet coins, it quickly led to a specialized hardware arms race. Bitcoin's network is currently supported by vast enterprises with millions of dollars of overhead in energy and specialized equipment. Blackcoin's supporting infrastructure is growing quickly, highlighted by the recent acceptance to CoinKite, a company offering user friendly web and point of sale solutions for merchants who wish to accept cryptocurrency. CoinKite had previously offered solutions only for Bitcoin and Litecoin, the two largest cryptocurrencies by market cap. Blackcoin will be the third coin added to Coinkite in June. Blackcoin is the clear choice for the environmentally-conscious individuals and buninesses looking for a green, energy efficient cryptocurrency or for those who believe in Satoshi Nakamoto's original vision of a completely decentralized cryptocurrency run by the people. Combined with Blackcoin's ten second ledger block generatin timeother advantages, the current market leaders in cryptocurrency, Bitcoin and Litecoin, may now have some serious competition on their hands.
submitted by RJSchex to blackcoin [link] [comments]

[Table] IamA Owner of a Bitcoin Accepting Subway in Allentown, PA (Sapan Shah) AMA!

Verified? (This bot cannot verify AMAs just yet)
Date: 2013-12-02
Link to submission (Has self-text)
Questions Answers
How has your staff taken to accepting bitcoins? Do the number of decimal places freak out the staff? Do you have a minimum purchase requirement for use of bitcoin? My employees are simply awesome. They have dealt with all of this with a smile on their faces and have actually shown a lot of interest.
They don't have to deal with decimals because I have set it up so all they have to do is input the total dollar amount into a tablet at the register. The app automatically generates the code that the customer scans. It pops up on the screen when they receive the payment.
We don't have a minimum purchase requirement.
Hi. How many bitcoin customers have you had so far? Are you a bitcoin investor as well? I can not disclose exact sale figures or numbers, however I can say it has steadily been growing. We have a couple bitcoin paying customers almost every day.
I am indeed a bitcoin investor myself.
How many times a week does someone ask you what a Bitcoin is? 4 Zillion.
Plain and simple.
I thought bitcoins were worth about 1K each. How would it work if I forked over a bitcoin for a Footlong Tuna Fish sandwich? We calculate the total sale amount (i.e. $10.53) and convert that to the equivalent Bitcoin value (roughly 10.09 mBTC or .01009 BTC). We generate a QR code with an address and the amount. The customer scans that code and sends us instant payment.
You can take a look at to see what I mean.
Don't sell yourself short, 10.09 milli would be .01009. roughly 10.09 mBTC or .001009 BTC. Would be $1.13. You are correct- I changed it..thank you :)
Do you immediately sell the bitcoins for cash to take away the currency risk or are you keeping the bitcoins in your account? This has been one of the most complicated parts of the process. Since I started accepting Bitcoins, I have switched my Merchant Services Processor 3 times. I am actually looking for a longer term solution. Until I find a more permanent solution that is fully integrated with our bank account, our Bitcoins are remaining as is.
Since this has been relatively new we are still working out all the kinks in the process. I am not worried about the currency risk at all.
How have you been keeping records of sales? I'm planning to accept Bitcoin but am unsure how to do so legally as a business. So you convert to USD and simply keep record of those earnings? Link to
I thought it took like an hour to confirm a bitcoin transaction. I remember reading that it was too slow for most consumer transactions like this. Am I completely misinformed? In our case, we have not had a payment take longer than 2-3 seconds. The merchant services take care of everything on the back end. A transaction has never taken us 1 hour to process.
Would you be able to pay an employee in BTC if they desired? There are no Bitcoin Payroll Services to my knowledge. I'm not sure how feasible this would be.
Is your store a franchise? - what do you do if the value of bitcoin drops? Does the company you go through for scanning take care of that? - what company do you use? - what kind of training did you give your employees? - if i wanted to start getting my local business owners in on this, what do you recommend i show them? Subway is indeed a franchise. We are currently using Coinbase to process our payments and I have personally walked all of my employees through the process.
I have found this page to be the most helpful if you want to show other small business owners: Link to
It was most helpful for me.
Was really excited to see the fact that more brick and mortar stores are accepting bitcoin, of course even more so when it was a more well known chain store (compared to a mom and pop place) Has the news coverage about this given you more business from local bitcoin users? Whats you're current process for accepting bitcoins (how do you go handle payments, exchanges and such)? I hope more businesses will begin accepting Bitcoin!
Ever heard of Coinkite? and if so would you consider using them as a way to accept bitcoins (and Litecoins?) *They're like a wallet service with a credit-card esque terminal where you get a bitcoin debit card and can make payments through that (or the traditional way of QR Codes works too) I did consider Coinkite. They were very nice and responsive, just not the right match for us at this time.
How can I persuade other Subway Owners to accept Bitcoin at their stores? This is a very good question. I think it is entirely up to the owner if they want to start accepting it or not. There is definitely a learning curve involved along with some risk and doubt.
A good start would be educating them about what a Bitcoin is. Even if you ultimately can't persuade them, at least you have taught one more person about Bitcoin.
The second thing maybe to show them some articles or videos about me accepting it. Tell them I have been accepting it for over a month. If they see another franchisee accepting it, they may be more willing to try it out.
Many may be deterred by the initial costs involved. Perhaps eliminating those costs would help to convince many to come on board. You could also try telling them it is non-binding, they don't have to sign a contract and there is no catch. Print out a sign and set it up for them. Tell them to try it out for a week and if they don't like it- ...nevermind, I doubt that will happen.
Can you write a little FAQ for Subway patrons to convince owners in their area to accept bitcoin? Would love a little list of hardware, software, which accounts to create with which companies, etc. Most of the equipment used in Subway's are fairly standard. I have a Nexus 7 next to my register with the POS app on there. They would just need to tweak some settings on the POS.
If you draft up some questions I might be able to help you out with an FAQ
I'm most curious about the things that would encourage or discourage a small business owner who is less knowledgeable/enthusiastic about bitcoin from accepting them. I've thought for a while that there is a need for somebody to create a well-executed, hard to screw-up, system for small businesses to accept bitcoins for in-person transactions. As far as I can tell, nothing like that exists on the market today, and most businesses accepting BTC are mostly rolling their own solution, at a high cost in time for whoever is managing it. Would you buy such a system, if it was available? I set up most of my system by myself. It took a little bit of technical knowledge (and interest). There are people available that can come in and set everything up, I just wanted to keep it simple and easy. I doubt other business owners would want to pay start up costs in addition to take the risk of accepting a new form of tender.
About how much time a week do you spend dealing with Bitcoin processing related issues? What was your worst week? What are the biggest pain points in accepting bitcoins right now? Training staff, integrating with existing POS systems, getting reliable conversions back to USD, something else? I don't spend too much time dealing with Bitcoin Processing related issues too much. They go fairly smoothly.
I'm from Plymouth Meeting, which is really close to Allentown! I think this is awesome, I should come buy something with Bitcoins sometime. Also, what was the most difficult part about integrating Bitcoins into your store? There have been so many challenges from the start. I think the biggest one has been trying to explain to everyone what a Bitcoin is. For example, in order to train my employees, they needed to fundamentally understand what a Bitcoin was. I had to explain it over and over again answering the same doubtful questions.
We would love to have you at our store!
Hey, you run the Subway by Dorney Park? Wow, I used to live right near there, worked at St Luke's in Bethlehem. Nostalgia. Not related to BitCoin, but what do you think of Allentown and LV in general? How long have you been there? Where are you originally from? Yep, Subway Dorneyville. I was born and brought up in Allentown!
Do you have any BTC for yourself? Also, what do you think about altcoins such as Litecoin, Namecoin, ect. I do have BTC myself. I do not have any plans to start accepting any Alt. currency at my store. I think they are very interesting and we may see many more in the future.
Hey there Sapan, I'm located in easton and I was just wondering which subway it is that you run so that I can possibly stop by and say hello?! Absolutely! Link to
I spend a lot of time in Allentown. Where is your store located? I'd love to stop by and buy some subway with bitcoins. Link to
Allentown resident here. Which Subway? Link to
Hey, I go to Lehigh. I'm literally in the building across the street from you. I was also your 2nd bitcoin customer. If I happen to see you, I'll say hi. Do say hi if you see me. I'm always there.
No questions, but thank you from the Dorney Park team for making lunch for us on many occasions! You guys are Awesome. Can't wait till everyone comes back in the Spring.
You're a very smart man according to the fever going on in bitcoin. Thank you, I'm not that smart. Just a man with a Sub...and a Bitcoin.
According to them, you are going to be a millionaire by accepting bitcoin right now. According to me. They all are probably millionaires. I've gotten to meet some of them in my store. Great group of people. on bitcoin.
Last updated: 2013-12-07 04:31 UTC
This post was generated by a robot! Send all complaints to epsy.
submitted by tabledresser to tabled [link] [comments]

How Much Can You Make Mining Bitcoin With 6X 1080 Ti ... Coinkite Bitcoin School - a collaboration with KISB for ... Coffee, Coinkite & Cryptocurrency New Wallet from Opendime, the Coinkite Coldcard, is Cypherpunk Cool - Bitcoin News BITCOIN MINER Version 2017 Real Bit Coin Generator Earn Free BTC

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bitcoin miner calculator, bitcoin miner cpu, bitcoin miner cheap, bitcoin miner chinese, c bitcoin miner, bitcoin miner d3, bitcoin miner device, bitcoin miner download, bitcoin miner download ... In this video you will learn how to permanently "engrave" your Bitcoin Wallet 24 words (BIP39) Seed backup on SEEDPLATE metal backup system. Get your SEEDPLA... This video is unavailable. Watch Queue Queue. Watch Queue Queue Queue Coinkite Bitcoin School - a collaboration with KISB for videos to teach you how to do Bitcoin safe and secure! A quick look at Coinkite's first batch of advanced bitcoin merchant terminals. Quickly pay with bitcoin or litecoin using a Coinkite debit card or any other wallet. More videos to come showing the ...