Bitcoin Hashrate Chart 2015 CoinWarz

Bitcoin 11 Years - Achievements, Lies, and Bullshit Claims So Far - Tooootally NOT a SCAM !!!!

That's right folks, it's that time again for the annual review of how Bitcoin is going: all of those claims, predictions, promises .... how many have turned out to be true, and how many are completely bogus ???
Please post / link this on Bitcoin (I am banned there for speaking the truth, so I cannot do it) ... because it'a way past time those poor clueless mushrooms were exposed to the truth.
Anyway, without further ado, I give you the Bitcoin's Achievements, Lies, and Bullshit Claims So Far ...
Bitcoin Achievements so far:
  1. It has spawned a cesspool of scams (2000+ shit coin scams, plus 100's of other scams, frauds, cons).
  2. Many 1,000's of hacks, thefts, losses.
  3. Illegal Use Cases: illegal drugs, illegal weapons, tax fraud, money laundering, sex trafficking, child pornography, hit men / murder-for-hire, ransomware, blackmail, extortion, and various other kinds of fraud and illicit activity.
  4. Legal Use Cases: Steam Games, Reddit, Expedia, Stripe, Starbucks, 1000's of merchants, cryptocurrency conferences, Ummm ????? The few merchants who "accept Bitcoin" immediately convert it into FIAT after the sale, or require you to sell your coins to BitPay or Coinbase for real money, and will then take that money. Some of the few who actually accept bitcoin haven't seen a customer who needed to pay with bitcoin for the last six months, and their cashiers no longer know how to handle that.
  5. Contributing significantly to Global Warming.
  6. Wastes vasts amounts of electricity on useless, do nothing work.
  7. Exponentially raises electricity prices when big miners move into regions where electricity was cheap.
  8. It’s the first "currency" that is not self-sustainable. It operates at a net loss, and requires continuous outside capital to replace the capital removed by miners to pay their costs. It’s literally a "black hole currency."
  9. It created a new way for people living too far from Vegas to gamble all their life savings away.
  10. Spawned "blockchain technology", a powerful technique that lets incompetent programmers who know almost nothing about databases, finance, programming, or blockchain scam millions out of gullible VC investors, banks, and governments.
  11. Increased China's foreign trade balance by a couple billion dollars per year.
  12. Helped the FBI and other law enforcement agents easily track down hundreds of drug traffickers and drug users.
  13. Wasted thousands if not millions of man-hours of government employees and legislators, in mostly fruitless attempts to understand, legitimize, and regulate the "phenomenon", and to investigate and prosecute its scams.
  14. Rekindled the hopes of anarcho-capitalists and libertarians for a global economic collapse, that would finally bring forth their Mad Max "utopia".
  15. Added another character to Unicode (no, no, not the "poo" 💩 character ... that was my first guess as well 🤣)
  16. Provides an easy way for malware and ransomware criminals to ply their trade and extort hospitals, schools, local councils, businesses, utilities, as well as the general population.
Correct Predictions:
  1. 2015-12: "1,000 dollar in 2015", u/Luka_Magnotta, aka time traveler from the future, 31-Aug-2013, (Technically, this prediction is WRONG because the highest price reached in 2015 was $495.56 according to CMC. Yes, Bitcoin reached $1,000 in 2013 and 2014, but that's NOT what the prediction says).
  2. 2017-12: "10,000 in 2017", u/Luka_Magnotta, aka time traveler from the future, 31-Aug-2013,
  3. 2018-04: $10,000 (by April 2018), Mike Novogratz, link #1:, link #2:
  4. 2018-12: $10,000 (by 2018), Tim Draper, link #1:, link #2:
  5. Any others ? (Please tell me).
Bitcoin Promises / Claims / Price Predictions that turned out to be lies and bullshit:
  7. SAFE
  10. NOT A SCAM
  15. Be your own bank
  16. Regulation-proof
  19. Instantaneous transactions
  20. Fast transactions
  21. Zero / No transaction fees
  22. Low transaction fees
  23. A store of value
  24. A deflationary digital asset
  25. "A deflationary digital asset that no single human being can destroy."
  26. "an asset that is equally as dual use as a car, water, or any other traditional element that has existed."
  27. "Digital gold"
  28. Easy to use
  29. Cannot be stolen
  30. Cannot be hacked
  31. Can be mined by anyone
  32. Can be mined by anyone, even with an old computer or laptop
  33. Cannot be centralized
  34. Will return power back to the people.
  35. Not a Ponzi scam
  36. Not a Pyramid scam
  37. Never pay tax again
  38. Your gains cannot be taxed
  39. A currency
  40. An amazing new class of asset
  41. An asset
  42. A means to economic freedom
  43. A store of value
  44. The best investment the word has ever seen
  45. A great investment
  46. Efficient
  47. Scalable
  48. Stable
  49. Resilient
  50. Reliable
  51. Low energy
  52. Low risk
  53. Redistribute wealth to everybody
  54. No more have's and have not's
  55. No more US and THEM
  56. No more disadvantaged people
  57. No more RICH and POOR
  58. No more poor people
  59. Uses amazing new technology
  60. Uses ingenious new technology
  61. Satishi Nakamoto invented ...
  62. Segwit will solve all of Bitcoin's woes
  63. Lightning Network will solve all of Bitcoin's woes
  64. Limited by scarcity
  65. Can only go up in value
  66. Price cannot crash
  67. Has intrinsic value
  68. Value will always be worth more than cost to mine
  69. Adoption by investors is increasing exponentially
  70. Adoption by investors is increasing
  71. Adoption by merchants is increasing exponentially
  72. Adoption by merchants is increasing
  73. You are secure if you keep your coins on an exchange
  74. You are secure if you keep your coins in a hardware wallet
  75. You are secure if you keep your coins in an air-gapped Linux PC
  76. Will change the world
  77. "the next phase in human evolution"
  78. "Blockchain is more encompassing than the internet"
  79. Blockchain can solve previously unsolvable problems.
  80. "The only regulation we need is the blockchain"
  81. "Bank the unbanked"
  82. "To abolish financial slavery and the state's toxic monopoly on money."
  83. "To have better tools in the fight against the state violence and taxation."
  84. "To stamp information on a blockchain forever so we can bypass state censorship, copyrights, patents(informational monopolies) etc."
  85. Will destroy / overthrow FIAT
  86. Will destroy / overthrow the world's governments
  87. Will destroy / overthrow the banking system
  88. Will destroy / overthrow the world economies
  89. Will free people from tyranny
  90. Will give people financial freedom
  91. Will bring world peace
  92. Never going below $19K again
  93. Never going below $18K again
  94. Never going below $17K again
  95. Never going below $16K again
  96. Never going below $15K again
  97. Never going below $14K again
  98. Never going below $13K again
  99. Never going below $12K again
  100. Never going below $11K again
  101. Never going below $10K again
  102. Never going below $9K again
  103. Never going below $8K again
  104. Never going below $7K again
  105. Never going below $6K again
  106. Never going below $5K again
  107. Never going below $4K again
  108. Is NOT a Scam
  109. Hashing Power secures the Bitcoin network
  110. Untraceable, private transactions
  111. Guaranteed privacy
  112. Not created out of thin air
  113. Not created out of thin air by unregulated, unbacked entities
  114. Totally NOT a scam
  115. Is not used primarily by crimonals, drug dealers, or money launderers.
  116. 100% secure
  117. 2010 will be the "Year of Crypto"
  118. 2011 will be the "Year of Crypto"
  119. 2012 will be the "Year of Crypto"
  120. 2013 will be the "Year of Crypto"
  121. 2014 will be the "Year of Crypto"
  122. 2015 will be the "Year of Crypto"
  123. 2016 will be the "Year of Crypto"
  124. 2017 will be the "Year of Crypto"
  125. 2018 will be the "Year of Crypto"
  126. 2019 will be the "Year of Crypto"
  127. 2010: MASS ADOPTION any day now"
  128. 2011: MASS ADOPTION aany day now"
  129. 2012: MASS ADOPTION aaany day now"
  130. 2013: MASS ADOPTION aaaany day now"
  131. 2014: MASS ADOPTION aaaaany day now"
  132. 2015: MASS ADOPTION aaaaaany day now"
  133. 2016: MASS ADOPTION aaaaaaany day now"
  134. 2017: MASS ADOPTION aaaaaaaany day now"
  135. 2018: MASS ADOPTION aaaaaaaaany day now"
  136. 2019: MASS ADOPTION aaaaaaaaany day now"
  137. "Financial Freedom, bro."
  138. no single entity, government or individual, can alter or reverse its transactions
  139. insurance against the tyranny of state
  140. Bitcoin has come to destroy all governments and bring about the libertarian utopia of my dreams.
  141. The major issues in Bicoin's network will be fixed. This is still early days, Bitcoin has only been around for 2+ years.
  142. The major issues in Bicoin's network will be fixed. This is still early days, Bitcoin has only been around for 5+ years.
  143. The major issues in Bicoin's network will be fixed. This is still early days, Bitcoin has only been around for 7+ years.
  144. The major issues in Bicoin's network will be fixed. This is still early days, Bitcoin has only been around for 9+ years.
  145. 1,000's of predictions of skyrocketing and/or never falling prices
  146. Escape the petty rivalries of warring powers and nation states by scattering control among the many. The Bitcoin Cash debacle proves that even the most cryptographically secure plans of mice and men often go awry. Ref:
  147. People will NEVER be able to welch out of bets or deals again. Nov-2018, Ref:
  148. "Everything will be better, faster, and cheaper.", Brock Pierce, shill video.
  149. "Everything will be more connected.", Brock Pierce, shill video.
  150. "Everything will be more trustworthy.", Brock Pierce, shill video.
  151. "Everything will be more secure.", Brock Pierce, shill video.
  152. "Everything that exists is no-longer going to exist in the way that it does today.", Brock Pierce, shill video.
  153. "Everything in this world is about to get better.", Brock Pierce, shill video.
  154. You are a slave to the bankers
  155. The bankers print money and then you pay for it
  156. Bitcoin is The Peoples Money
  157. Bitcoin will set you free
  158. Bitcoin will set you free from the slavery of the banks and the government Ref:
  159. ~~Bitcoin is "striking fear into the hearts of bankers, precisely because Bitcoin eliminates the need for banks. ~~, Mark Yusko, billionaire investor and Founder of Morgan Creek Capital,
  160. "When transactions are verified on a Blockchain, banks become obsolete.", Mark Yusko, billionaire investor and Founder of Morgan Creek Capital,
  161. SnapshillBot quotes from delusional morons:
  162. "A bitcoin miner in every device and in every hand."
  163. "All the indicators are pointing to a huge year and bigger than anything we have seen before."
  164. "Bitcoin is communism and democracy working hand in hand."
  165. "Bitcoin is freedom, and we will soon be free."
  166. "Bitcoin isn't calculated risk, you're right. It's downright and painfully obvious that it will consume global finance."
  167. "Bitcoin most disruptive technology of last 500 years"
  168. "Bitcoin: So easy, your grandma can use it!"
  169. "Creating a 4th Branch of Government - Bitcoin"
  170. "Future generations will cry laughing reading all the negativity and insanity vomited by these permabears."
  171. "Future us will thank us."
  172. "Give Bitcoin two years"
  173. "HODLING is more like being a dutiful guardian of the most powerful economic force this planet has ever seen and getting to have a say about how that force is unleashed."
  174. "Cut out the middleman"
  175. "full control of your own assets"
  176. "reduction in wealth gap"
  177. "no inflation"
  178. "cannot print money out of thin air"
  179. "Why that matters? Because blockchain not only cheaper for them, it'll be cheaper for you and everyone as well."
  180. "If you are in this to get rich in Fiat then no. But if you are in this to protect your wealth once the current monetary system collapse then you are protected and you'll be the new rich."
  181. "Theres the 1% and then theres the 99%. You want to be with the rest thats fine. Being different and brave is far more rewarding. No matter your background or education."
  182. "NO COINERS will believe anything they are fed by fake news and paid media."
  183. "I know that feeling (like people looking at you as in seeing a celebrity and then asking things they don't believe until their impressed)."
  184. "I literally walk round everyday looking at other people wondering why they even bother to live if they don't have Bitcoin in their lives."
  185. "I think bitcoin may very well be the best form of money we’ve ever seen in the history of civilization."
  186. "I think Bitcoin will do for mankind what the sun did for life on earth."
  187. "I think the constant scams and illegal activities only show the viability of bitcoin."
  188. "I think we're sitting on the verge of exponential interest in the currency."
  189. "I'm not using hyperbole when I say Satoshi found the elusive key to World Peace."
  190. "If Jesus ever comes back you know he's gonna be using Bitcoin"
  191. "If this idea was implemented with The Blockchain™, it would be completely flawless! Flawless I tell you!"
  192. "If you're the minimum wage guy type, now is a great time to skip food and go full ramadan in order to buy bitcoin instead."
  193. "In a world slipping more and more into chaos and uncertainty, Bitcoin seems to me like the last solid rock defeating all the attacks."
  194. "In this moment, I am euphoric. Not because of any filthy statist's blessing, but because I am enlightened by own intelligence."
  195. "Is Bitcoin at this point, with all the potential that opens up, the most undervalued asset ever?"
  196. "It won't be long until bitcoin is an everyday household term."
  197. "It's the USD that is volatile. Bitcoin is the real neutral currency."
  198. "Just like the early Internet!"
  199. "Just like the Trojan Horse of old, Bitcoin will reveal its full power and nature"
  200. "Ladies if your man doesnt have some bitcoin then he cant handle anything and has no danger sex appeal. He isnt edgy"
  201. "let me be the first to say if you dont have bitcoin you are a pussy and cant really purchase anything worldwide. You have no global reach"
  202. "My conclusion is that I see this a a very good thing for bitcoin and for users"
  203. "No one would do such a thing; it'd be against their self interests."
  204. "Ooh lala, good job on bashing Bitcoin. How to disrespect a great innovation."
  205. "Realistically I think Bitcoin will replace the dollar in the next 10-15 years."
  206. "Seperation of money and state -> states become obsolete -> world peace."
  207. "Some striking similarities between Bitcoin and God"
  208. "THANK YOU. Better for this child to be strangled in its crib as a true weapon for crypto-anarchists than for it to be wielded by toxic individuals who distort the technology and surrender it to government and corporate powers."
  209. "The Blockchain is more encompassing than the internet and is the next phase in human evolution. To avoid its significance is complete ignorance."
  210. "The bull run should begin any day now."
  211. "The free market doesn't permit fraud and theft."
  212. "The free market will clear away the bad actors."
  213. "The only regulation we need is the blockchain."
  214. "We are not your slaves! We are free bodies who will swallow you and puke you out in disgust. Welcome to liberty land or as that genius called it: Bitcoin."
  215. "We do not need the bankers for Satoshi is our saviour!"
  216. "We have never seen something so perfect"
  217. "We must bring freedom and crypto to the masses, to the common man who does not know how to fight for himself."
  218. "We verified that against the blockchain."
  219. "we will see a Rennaisnce over the next few decades, all thanks to Bitcoin."
  220. "Well, since 2006, there has been a infinite% increase in price, so..."
  221. "What doesn't kill cryptocurrency makes it stronger."
  222. "When Bitcoin awake in normally people (real people) ... you will have this result : No War. No Tax. No QE. No Bank."
  223. "When I see news that the price of bitcoin has tanked (and thus the market, more or less) I actually, for-real, have the gut reaction "oh that’s cool, I’ll be buying cheap this week". I never knew I could be so rational."
  224. "Where is your sense of adventure? Bitcoin is the future. Set aside your fears and leave easier at the doorstep."
  225. "Yes Bitcoin will cause the greatest redistribution of wealth this planet has ever seen. FACT from the future."
  226. "You are the true Bitcoin pioneers and with your help we have imprinted Bitcoin in the Canadian conscience."
  227. "You ever try LSD? Perhaps it would help you break free from the box of state-formed thinking you have limited yourself..."
  228. "Your phone or refrigerator might be on the blockchain one day."
  229. The banks can print money whenever they way, out of thin air, so why can't crypto do the same ???
  230. Central Banks can print money whenever they way, out of thin air, without any consequences or accounting, so why can't crypto do the same ???
  231. It's impossible to hide illegal, unsavory material on the blockchain
  232. It's impossible to hide child pornography on the blockchain
  233. Fungible
  234. All Bitccoins are the same, 100% identical, one Bitcoin cannot be distinguished from any other Bitcoin.
  235. The price of Bitcoin can only go up.
  236. "Bubbles are mathematically impossible in this new paradigm. So are corrections and all else", John McAfee, 7 Dec 2017 @ 5:09 PM,
  237. Scarcity
  238. The price of Bitcoin can only go up because of scarcity / 21 million coin limit. (Bitcoin is open source, anyone can create thir own copy, and there are more than 2,000+ Bitcoin copies / clones out there already).
  239. immune to government regulation
  240. "a world-changing technology"
  241. "a long-term store of value, like gold or silver"
  242. "To Complex to Be Audited."
  243. "Old Auditing rules do not apply to Blockchain."
  244. "Old Auditing rules do not apply to Cryptocurrency."
  245. "Why Bitcoin has Value: SCARCITY.", PlanB, Coin Shill, 22-Mar-2019,
  246. "Bitcoin is the first scarce digital object the world has ever seen, it is scarce like silver & gold, and can be sent over the internet, radio, satellite etc.", PlanB, Coin Shill, 22-Mar-2019,
  247. "Surely this digital scarcity has value.", PlanB, Coin Shill, 22-Mar-2019,
  248. Bitcoin now at $16,600.00. Those of you in the old school who believe this is a bubble simply have not understood the new mathematics of the Blockchain, or you did not cared enough to try. Bubbles are mathematically impossible in this new paradigm. So are corrections and all else", John McAfee, 7 Dec 2017 @ 5:09 PM,
  249. "May 2018 will be the last time we ever see $bitcoin under $10,000", Charlie Shrem, bitcoin advocate and convicted felon, 11:31 AM 3-May-2018,
  250. "Last dip ever.", AngeloBTC, 14 Oct 2018,
  251. "Bitcoin May Have Just Experienced its Final Shakeout Before a Big Rally", Joseph Young, coin shill, October 15, 2018 22:30 CET,
  252. Bitcoin would be a buy if the price fell under $5,000., Mohamed El-Erian, chief economic advisor at Allianz, 29-Jun-2018,
  253. 2013-11-27: ""What is a Citadel?" you might wonder. Well, by the time Bitcoin became worth 1,000 dollar [27-Nov-2013], services began to emerge for the "Bitcoin rich" to protect themselves as well as their wealth. It started with expensive safes, then began to include bodyguards, and today, "earlies" (our term for early adapters), as well as those rich whose wealth survived the "transition" live in isolated gated cities called Citadels, where most work is automated. Most such Citadels are born out of the fortification used to protect places where Bitcoin mining machines are located. The company known as ASICminer to you is known to me as a city where Mr. Friedman rules as a king.", u/Luka_Magnotta, aka time traveler from the future, 31-Aug-2013,
  254. 2018-02: Bitcoin price to hit $27,000 by February 2018, Trace Mayer, host of the Bitcoin Knowledge Podcast, and self-proclaimed entrepreneur, investor, journalist, monetary scientist and ardent defender, Link #1:, Link #2:
  255. 2018-06: "Bitcoin will surpass $15,000 in June [2018]." John McAfee, May 25, 2018,
  256. 2018-07: Bitcoin will be $28,000 by mid-2018, Ronnie Moas, Wall Street analyst and founder of Standpoint Research,
  257. 2018-12: Bitcoin to reach a price of between 40,000 and 110,000 US dollars by the end of the 2017 bull run ... sometime before 2019, Masterluc, 26-May-2017, an anonymous "legendary" Bitcoin trader, Link #1:, Link #2:
  258. 2018-12: "There is no reason why we couldn’t see Bitcoin pushing $50,000 by December [2018]", Thomas Glucksmann, head of APAC business at Gatecoin, Link #1:
  259. 2018-12: Listen up you giggling cunts... who wants some? you want some?...huh? Do ya? Here's the deal you fuckin Nerds - Butts are gonna be at 30 grand or more by next Christmas [2018] - If they aren't I will publicly administer an electronic dick sucking to every shill on this site and disappear forever - Until then, no more bans or shadow bans - Do we have a deal? If Butts are over 50 grand me and Lammy get to be mods. Deal? Your ole pal - "Skully" u/10GDeathBoner, 3-Feb-2018
  260. 2018-12: 1 bitcoin = 1 Lambo. Remind me on Christmas eve [2018] u/10GDeathBoner, 3-Feb-2018,
  261. 2018-12: Been in BTC since 2014 and experienced many "deaths" of BTC... this too shall pass... $10k end of the year. [2018] u/Exxe2502, 30-Jun-2018
  262. 2018-12: "Yale Alumni prediction - 30 Grand by Christmas [2018] - and you my friend... you will be the one eating Mcafee's dick in 2020. :) -:", u/SirNakamoto, 15-Jun-2018,
  263. 2018-12: "Impossible For Bitcoin Not to Hit $10,000 by This Year (2018)", Mike Novogratz, a former Goldman Sachs Group Inc. partner, ex-hedge fund manager of the Fortress Investment Group and a longstanding advocate of cryptocurrency, 22-Sep-2018,
  264. 2018-12: "[Bitcoin] between $13,800 and $14,800 [by end of 2018]", Fundstrat's Tom Lee, 13-Dec-2018,
  265. 2018-12: "Bitcoin is going to be $15k-$20k by the end of the year (2018)", Didi Taihuttu, 1-Nov-2018,
  266. 2018-12: 2018 bitcoin price prediction reduced to $15,000 [was $25,000], Fundstrat's Tom Lee, 16-Nov-2018,
  267. 2018-12: "I want to be clear, bitcoin is going to $25,000 by year end (2018)", Fundstrat's Tom Lee, 5-Jul-2018,
  268. 2018-12: "Bitcoin could be at $40,000 by the end of 2018, it really easily could", Mike Novogratz, a former Goldman Sachs Group Inc. partner, ex-hedge fund manager of the Fortress Investment Group and a longstanding advocate of cryptocurrency, 21-Sep-2018,
  269. 2018-12: "Bitcoin will be priced around $50,000 by the end of the year (2018)", Bitcoin bull Arthur Hayes, co-founder and CEO of BitMEX, 29-Jun-2018,
  270. 2018-12: "Bitcoin could definitely see $50,000 in 2018", Jeet Singh, cryptocurrency portfolio manager, speaking in January 2018 at the World Economic Forum in Davos,
  271. 2018-12: "Bitcoin will hit $100,000 this year (2018)", Kay Van-Petersen, an analyst at Saxo Bank, 17-Jan-2018,
  272. 2018-12: "Bitcoin price to surpass the $100,000 mark by the end of 2018", Tone Vays, 21-Sep-2017,
  273. 2018-12: "Bitcoin’s Price Will Surpass the $100,000 Mark by the End of 2018", Anonymous ("author" obviously too embarrassed to put his name to such bullshit "articles"), Oct-2018,
  274. 2018-12: "Our [2018] year-end bitcoin target is $7700.", James Stefurak, Founder at Monarch Research. See article: "Experts Forecast Bitcoin will rise by 2019", REF:
  275. 2018-12: "... we’ll see the price rally reaching its all-time of high of around $20K before the end of 2018", Khaled Khorshid, Co-Founder at Treon ICO. See article: "Experts Forecast Bitcoin will rise by 2019", REF:
  276. 2018-12: Bitcoin will end 2018 at the price point of $50,000, Ran Neuner, host of CNBC’s show Cryptotrader and the 28th most influential Blockchain insider according to Richtopia,
  277. Plus a whole host of wrong 2019 predictions (could not be included here because of post character limit issues), so please see my earlier post from 4 days ago: Ummm, remember those "Expert" Bitcoin Price Predictions for 2019 ..... ohhhhh dear .....,
But it's NOT all bad news, some claims and promises are yet to be determined:
  1. Never going below $3K again
  2. Never going below $2K again
  3. Never going below $1K again
  4. Any others ? Please let me know.
submitted by Crypto_To_The_Core to Buttcoin [link] [comments]

Bitcoin-NG: A Scalable Blockchain Protocol

Date: 2015-11-11
Author(s): Ittay Eyal, Adem Efe Gencer, Emin Gun Sirer, Robbert van Renesse

Link to Paper

Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous online payments, cheap remittance, trustless digital asset exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade-off between throughput and latency and withhold the realization of this potential.This paper presents Bitcoin-NG, a new blockchain protocol designed to scale. Based on Bitcoin's blockchain protocol, Bitcoin-NG is Byzantine fault tolerant, is robust to extreme churn, and shares the same trust model obviating qualitative changes to the ecosystem.In addition to Bitcoin-NG, we introduce several novel metrics of interest in quantifying the security and efficiency of Bitcoin-like blockchain protocols. We implement Bitcoin-NG and perform large-scale experiments at 15% the size of the operational Bitcoin system, using unchanged clients of both protocols. These experiments demonstrate that Bitcoin-NG scales optimally, with bandwidth limited only by the capacity of the individual nodes and latency limited only by the propagation time of the network.

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submitted by dj-gutz to myrXiv [link] [comments]

Merkle Trees and Mountain Ranges - Making UTXO Set Growth Irrelevant With Low-Latency Delayed TXO Commitments

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Unedited text and originally written by:

Peter Todd pete at
Tue May 17 13:23:11 UTC 2016
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# Motivation

UTXO growth is a serious concern for Bitcoin's long-term decentralization. To
run a competitive mining operation potentially the entire UTXO set must be in
RAM to achieve competitive latency; your larger, more centralized, competitors
will have the UTXO set in RAM. Mining is a zero-sum game, so the extra latency
of not doing so if they do directly impacts your profit margin. Secondly,
having possession of the UTXO set is one of the minimum requirements to run a
full node; the larger the set the harder it is to run a full node.

Currently the maximum size of the UTXO set is unbounded as there is no
consensus rule that limits growth, other than the block-size limit itself; as
of writing the UTXO set is 1.3GB in the on-disk, compressed serialization,
which expands to significantly more in memory. UTXO growth is driven by a
number of factors, including the fact that there is little incentive to merge
inputs, lost coins, dust outputs that can't be economically spent, and
non-btc-value-transfer "blockchain" use-cases such as anti-replay oracles and

We don't have good tools to combat UTXO growth. Segregated Witness proposes to
give witness space a 75% discount, in part of make reducing the UTXO set size
by spending txouts cheaper. While this may change wallets to more often spend
dust, it's hard to imagine an incentive sufficiently strong to discourage most,
let alone all, UTXO growing behavior.

For example, timestamping applications often create unspendable outputs due to
ease of implementation, and because doing so is an easy way to make sure that
the data required to reconstruct the timestamp proof won't get lost - all
Bitcoin full nodes are forced to keep a copy of it. Similarly anti-replay
use-cases like using the UTXO set for key rotation piggyback on the uniquely
strong security and decentralization guarantee that Bitcoin provides; it's very
difficult - perhaps impossible - to provide these applications with
alternatives that are equally secure. These non-btc-value-transfer use-cases
can often afford to pay far higher fees per UTXO created than competing
btc-value-transfer use-cases; many users could afford to spend $50 to register
a new PGP key, yet would rather not spend $50 in fees to create a standard two
output transaction. Effective techniques to resist miner censorship exist, so
without resorting to whitelists blocking non-btc-value-transfer use-cases as
"spam" is not a long-term, incentive compatible, solution.

A hard upper limit on UTXO set size could create a more level playing field in
the form of fixed minimum requirements to run a performant Bitcoin node, and
make the issue of UTXO "spam" less important. However, making any coins
unspendable, regardless of age or value, is a politically untenable economic

# TXO Commitments

A merkle tree committing to the state of all transaction outputs, both spent
and unspent, we can provide a method of compactly proving the current state of
an output. This lets us "archive" less frequently accessed parts of the UTXO
set, allowing full nodes to discard the associated data, still providing a
mechanism to spend those archived outputs by proving to those nodes that the
outputs are in fact unspent.

Specifically TXO commitments proposes a Merkle Mountain Range¹ (MMR), a
type of deterministic, indexable, insertion ordered merkle tree, which allows
new items to be cheaply appended to the tree with minimal storage requirements,
just log2(n) "mountain tips". Once an output is added to the TXO MMR it is
never removed; if an output is spent its status is updated in place. Both the
state of a specific item in the MMR, as well the validity of changes to items
in the MMR, can be proven with log2(n) sized proofs consisting of a merkle path
to the tip of the tree.

At an extreme, with TXO commitments we could even have no UTXO set at all,
entirely eliminating the UTXO growth problem. Transactions would simply be
accompanied by TXO commitment proofs showing that the outputs they wanted to
spend were still unspent; nodes could update the state of the TXO MMR purely
from TXO commitment proofs. However, the log2(n) bandwidth overhead per txin is
substantial, so a more realistic implementation is be to have a UTXO cache for
recent transactions, with TXO commitments acting as a alternate for the (rare)
event that an old txout needs to be spent.

Proofs can be generated and added to transactions without the involvement of
the signers, even after the fact; there's no need for the proof itself to
signed and the proof is not part of the transaction hash. Anyone with access to
TXO MMR data can (re)generate missing proofs, so minimal, if any, changes are
required to wallet software to make use of TXO commitments.

## Delayed Commitments

TXO commitments aren't a new idea - the author proposed them years ago in
response to UTXO commitments. However it's critical for small miners' orphan
rates that block validation be fast, and so far it has proven difficult to
create (U)TXO implementations with acceptable performance; updating and
recalculating cryptographicly hashed merkelized datasets is inherently more
work than not doing so. Fortunately if we maintain a UTXO set for recent
outputs, TXO commitments are only needed when spending old, archived, outputs.
We can take advantage of this by delaying the commitment, allowing it to be
calculated well in advance of it actually being used, thus changing a
latency-critical task into a much easier average throughput problem.

Concretely each block B_i commits to the TXO set state as of block B_{i-n}, in
other words what the TXO commitment would have been n blocks ago, if not for
the n block delay. Since that commitment only depends on the contents of the
blockchain up until block B_{i-n}, the contents of any block after are
irrelevant to the calculation.

## Implementation

Our proposed high-performance/low-latency delayed commitment full-node
implementation needs to store the following data:

1) UTXO set

Low-latency K:V map of txouts definitely known to be unspent. Similar to
existing UTXO implementation, but with the key difference that old,
unspent, outputs may be pruned from the UTXO set.

2) STXO set

Low-latency set of transaction outputs known to have been spent by
transactions after the most recent TXO commitment, but created prior to the
TXO commitment.

3) TXO journal

FIFO of outputs that need to be marked as spent in the TXO MMR. Appends
must be low-latency; removals can be high-latency.

4) TXO MMR list

Prunable, ordered list of TXO MMR's, mainly the highest pending commitment,
backed by a reference counted, cryptographically hashed object store
indexed by digest (similar to how git repos work). High-latency ok. We'll
cover this in more in detail later.

### Fast-Path: Verifying a Txout Spend In a Block

When a transaction output is spent by a transaction in a block we have two

1) Recently created output

Output created after the most recent TXO commitment, so it should be in the
UTXO set; the transaction spending it does not need a TXO commitment proof.
Remove the output from the UTXO set and append it to the TXO journal.

2) Archived output

Output created prior to the most recent TXO commitment, so there's no
guarantee it's in the UTXO set; transaction will have a TXO commitment
proof for the most recent TXO commitment showing that it was unspent.
Check that the output isn't already in the STXO set (double-spent), and if
not add it. Append the output and TXO commitment proof to the TXO journal.

In both cases recording an output as spent requires no more than two key:value
updates, and one journal append. The existing UTXO set requires one key:value
update per spend, so we can expect new block validation latency to be within 2x
of the status quo even in the worst case of 100% archived output spends.

### Slow-Path: Calculating Pending TXO Commitments

In a low-priority background task we flush the TXO journal, recording the
outputs spent by each block in the TXO MMR, and hashing MMR data to obtain the
TXO commitment digest. Additionally this background task removes STXO's that
have been recorded in TXO commitments, and prunes TXO commitment data no longer

Throughput for the TXO commitment calculation will be worse than the existing
UTXO only scheme. This impacts bulk verification, e.g. initial block download.
That said, TXO commitments provides other possible tradeoffs that can mitigate
impact of slower validation throughput, such as skipping validation of old
history, as well as fraud proof approaches.

### TXO MMR Implementation Details

Each TXO MMR state is a modification of the previous one with most information
shared, so we an space-efficiently store a large number of TXO commitments
states, where each state is a small delta of the previous state, by sharing
unchanged data between each state; cycles are impossible in merkelized data
structures, so simple reference counting is sufficient for garbage collection.
Data no longer needed can be pruned by dropping it from the database, and
unpruned by adding it again. Since everything is committed to via cryptographic
hash, we're guaranteed that regardless of where we get the data, after
unpruning we'll have the right data.

Let's look at how the TXO MMR works in detail. Consider the following TXO MMR
with two txouts, which we'll call state #0:

/ \
a b

If we add another entry we get state #1:

/ \
0 \
/ \ \
a b c

Note how it 100% of the state #0 data was reused in commitment #1. Let's
add two more entries to get state #2:

/ \
2 \
/ \ \
/ \ \
/ \ \
0 2 \
/ \ / \ \
a b c d e

This time part of state #1 wasn't reused - it's wasn't a perfect binary
tree - but we've still got a lot of re-use.

Now suppose state #2 is committed into the blockchain by the most recent block.
Future transactions attempting to spend outputs created as of state #2 are
obliged to prove that they are unspent; essentially they're forced to provide
part of the state #2 MMR data. This lets us prune that data, discarding it,
leaving us with only the bare minimum data we need to append new txouts to the
TXO MMR, the tips of the perfect binary trees ("mountains") within the MMR:

/ \
2 \

Note that we're glossing over some nuance here about exactly what data needs to
be kept; depending on the details of the implementation the only data we need
for nodes "2" and "e" may be their hash digest.

Adding another three more txouts results in state #3:

/ \
/ \
/ \
/ \
/ \
/ \
/ \
2 3
/ \
/ \
/ \
3 3
/ \ / \
e f g h

Suppose recently created txout f is spent. We have all the data required to
update the MMR, giving us state #4. It modifies two inner nodes and one leaf

/ \
/ \
/ \
/ \
/ \
/ \
/ \
2 4
/ \
/ \
/ \
4 3
/ \ / \
e (f) g h

If an archived txout is spent requires the transaction to provide the merkle
path to the most recently committed TXO, in our case state #2. If txout b is
spent that means the transaction must provide the following data from state #2:


We can add that data to our local knowledge of the TXO MMR, unpruning part of

/ \
/ \
/ \
/ \
/ \
/ \
/ \
2 4
/ / \
/ / \
/ / \
0 4 3
\ / \ / \
b e (f) g h

Remember, we haven't _modified_ state #4 yet; we just have more data about it.
When we mark txout b as spent we get state #5:

/ \
/ \
/ \
/ \
/ \
/ \
/ \
5 4
/ / \
/ / \
/ / \
5 4 3
\ / \ / \
(b) e (f) g h

Secondly by now state #3 has been committed into the chain, and transactions
that want to spend txouts created as of state #3 must provide a TXO proof
consisting of state #3 data. The leaf nodes for outputs g and h, and the inner
node above them, are part of state #3, so we prune them:

/ \
/ \
/ \
/ \
/ \
/ \
/ \
5 4
/ /
/ /
/ /
5 4
\ / \
(b) e (f)

Finally, lets put this all together, by spending txouts a, c, and g, and
creating three new txouts i, j, and k. State #3 was the most recently committed
state, so the transactions spending a and g are providing merkle paths up to
it. This includes part of the state #2 data:

/ \
/ \
/ \
/ \
/ \
/ \
/ \
2 3
/ \ \
/ \ \
/ \ \
0 2 3
/ / /
a c g

After unpruning we have the following data for state #5:

/ \
/ \
/ \
/ \
/ \
/ \
/ \
5 4
/ \ / \
/ \ / \
/ \ / \
5 2 4 3
/ \ / / \ /
a (b) c e (f) g

That's sufficient to mark the three outputs as spent and add the three new
txouts, resulting in state #6:

/ \
/ \
/ \
/ \
/ \
6 \
/ \ \
/ \ \
/ \ \
/ \ \
/ \ \
/ \ \
/ \ \
6 6 \
/ \ / \ \
/ \ / \ 6
/ \ / \ / \
6 6 4 6 6 \
/ \ / / \ / / \ \
(a) (b) (c) e (f) (g) i j k

Again, state #4 related data can be pruned. In addition, depending on how the
STXO set is implemented may also be able to prune data related to spent txouts
after that state, including inner nodes where all txouts under them have been
spent (more on pruning spent inner nodes later).

### Consensus and Pruning

It's important to note that pruning behavior is consensus critical: a full node
that is missing data due to pruning it too soon will fall out of consensus, and
a miner that fails to include a merkle proof that is required by the consensus
is creating an invalid block. At the same time many full nodes will have
significantly more data on hand than the bare minimum so they can help wallets
make transactions spending old coins; implementations should strongly consider
separating the data that is, and isn't, strictly required for consensus.

A reasonable approach for the low-level cryptography may be to actually treat
the two cases differently, with the TXO commitments committing too what data
does and does not need to be kept on hand by the UTXO expiration rules. On the
other hand, leaving that uncommitted allows for certain types of soft-forks
where the protocol is changed to require more data than it previously did.

### Consensus Critical Storage Overheads

Only the UTXO and STXO sets need to be kept on fast random access storage.
Since STXO set entries can only be created by spending a UTXO - and are smaller
than a UTXO entry - we can guarantee that the peak size of the UTXO and STXO
sets combined will always be less than the peak size of the UTXO set alone in
the existing UTXO-only scheme (though the combined size can be temporarily
higher than what the UTXO set size alone would be when large numbers of
archived txouts are spent).

TXO journal entries and unpruned entries in the TXO MMR have log2(n) maximum
overhead per entry: a unique merkle path to a TXO commitment (by "unique" we
mean that no other entry shares data with it). On a reasonably fast system the
TXO journal will be flushed quickly, converting it into TXO MMR data; the TXO
journal will never be more than a few blocks in size.

Transactions spending non-archived txouts are not required to provide any TXO
commitment data; we must have that data on hand in the form of one TXO MMR
entry per UTXO. Once spent however the TXO MMR leaf node associated with that
non-archived txout can be immediately pruned - it's no longer in the UTXO set
so any attempt to spend it will fail; the data is now immutable and we'll never
need it again. Inner nodes in the TXO MMR can also be pruned if all leafs under
them are fully spent; detecting this is easy the TXO MMR is a merkle-sum tree,
with each inner node committing to the sum of the unspent txouts under it.

When a archived txout is spent the transaction is required to provide a merkle
path to the most recent TXO commitment. As shown above that path is sufficient
information to unprune the necessary nodes in the TXO MMR and apply the spend
immediately, reducing this case to the TXO journal size question (non-consensus
critical overhead is a different question, which we'll address in the next

Taking all this into account the only significant storage overhead of our TXO
commitments scheme when compared to the status quo is the log2(n) merkle path
overhead; as long as less than 1/log2(n) of the UTXO set is active,
non-archived, UTXO's we've come out ahead, even in the unrealistic case where
all storage available is equally fast. In the real world that isn't yet the
case - even SSD's significantly slower than RAM.

### Non-Consensus Critical Storage Overheads

Transactions spending archived txouts pose two challenges:

1) Obtaining up-to-date TXO commitment proofs

2) Updating those proofs as blocks are mined

The first challenge can be handled by specialized archival nodes, not unlike
how some nodes make transaction data available to wallets via bloom filters or
the Electrum protocol. There's a whole variety of options available, and the
the data can be easily sharded to scale horizontally; the data is
self-validating allowing horizontal scaling without trust.

While miners and relay nodes don't need to be concerned about the initial
commitment proof, updating that proof is another matter. If a node aggressively
prunes old versions of the TXO MMR as it calculates pending TXO commitments, it
won't have the data available to update the TXO commitment proof to be against
the next block, when that block is found; the child nodes of the TXO MMR tip
are guaranteed to have changed, yet aggressive pruning would have discarded that

Relay nodes could ignore this problem if they simply accept the fact that
they'll only be able to fully relay the transaction once, when it is initially
broadcast, and won't be able to provide mempool functionality after the initial
relay. Modulo high-latency mixnets, this is probably acceptable; the author has
previously argued that relay nodes don't need a mempool² at all.

For a miner though not having the data necessary to update the proofs as blocks
are found means potentially losing out on transactions fees. So how much extra
data is necessary to make this a non-issue?

Since the TXO MMR is insertion ordered, spending a non-archived txout can only
invalidate the upper nodes in of the archived txout's TXO MMR proof (if this
isn't clear, imagine a two-level scheme, with a per-block TXO MMRs, committed
by a master MMR for all blocks). The maximum number of relevant inner nodes
changed is log2(n) per block, so if there are n non-archival blocks between the
most recent TXO commitment and the pending TXO MMR tip, we have to store
log2(n)*n inner nodes - on the order of a few dozen MB even when n is a
(seemingly ridiculously high) year worth of blocks.

Archived txout spends on the other hand can invalidate TXO MMR proofs at any
level - consider the case of two adjacent txouts being spent. To guarantee
success requires storing full proofs. However, they're limited by the blocksize
limit, and additionally are expected to be relatively uncommon. For example, if
1% of 1MB blocks was archival spends, our hypothetical year long TXO commitment
delay is only a few hundred MB of data with low-IO-performance requirements.

## Security Model

Of course, a TXO commitment delay of a year sounds ridiculous. Even the slowest
imaginable computer isn't going to need more than a few blocks of TXO
commitment delay to keep up ~100% of the time, and there's no reason why we
can't have the UTXO archive delay be significantly longer than the TXO
commitment delay.

However, as with UTXO commitments, TXO commitments raise issues with Bitcoin's
security model by allowing relatively miners to profitably mine transactions
without bothering to validate prior history. At the extreme, if there was no
commitment delay at all at the cost of a bit of some extra network bandwidth
"full" nodes could operate and even mine blocks completely statelessly by
expecting all transactions to include "proof" that their inputs are unspent; a
TXO commitment proof for a commitment you haven't verified isn't a proof that a
transaction output is unspent, it's a proof that some miners claimed the txout
was unspent.

At one extreme, we could simply implement TXO commitments in a "virtual"
fashion, without miners actually including the TXO commitment digest in their
blocks at all. Full nodes would be forced to compute the commitment from
scratch, in the same way they are forced to compute the UTXO state, or total
work. Of course a full node operator who doesn't want to verify old history can
get a copy of the TXO state from a trusted source - no different from how you
could get a copy of the UTXO set from a trusted source.

A more pragmatic approach is to accept that people will do that anyway, and
instead assume that sufficiently old blocks are valid. But how old is
"sufficiently old"? First of all, if your full node implementation comes "from
the factory" with a reasonably up-to-date minimum accepted total-work
thresholdⁱ - in other words it won't accept a chain with less than that amount
of total work - it may be reasonable to assume any Sybil attacker with
sufficient hashing power to make a forked chain meeting that threshold with,
say, six months worth of blocks has enough hashing power to threaten the main
chain as well.

That leaves public attempts to falsify TXO commitments, done out in the open by
the majority of hashing power. In this circumstance the "assumed valid"
threshold determines how long the attack would have to go on before full nodes
start accepting the invalid chain, or at least, newly installed/recently reset
full nodes. The minimum age that we can "assume valid" is tradeoff between
political/social/technical concerns; we probably want at least a few weeks to
guarantee the defenders a chance to organise themselves.

With this in mind, a longer-than-technically-necessary TXO commitment delayʲ
may help ensure that full node software actually validates some minimum number
of blocks out-of-the-box, without taking shortcuts. However this can be
achieved in a wide variety of ways, such as the author's prev-block-proof
proposal³, fraud proofs, or even a PoW with an inner loop dependent on
blockchain data. Like UTXO commitments, TXO commitments are also potentially
very useful in reducing the need for SPV wallet software to trust third parties
providing them with transaction data.

i) Checkpoints that reject any chain without a specific block are a more
common, if uglier, way of achieving this protection.

j) A good homework problem is to figure out how the TXO commitment could be
designed such that the delay could be reduced in a soft-fork.

## Further Work

While we've shown that TXO commitments certainly could be implemented without
increasing peak IO bandwidth/block validation latency significantly with the
delayed commitment approach, we're far from being certain that they should be
implemented this way (or at all).

1) Can a TXO commitment scheme be optimized sufficiently to be used directly
without a commitment delay? Obviously it'd be preferable to avoid all the above
complexity entirely.

2) Is it possible to use a metric other than age, e.g. priority? While this
complicates the pruning logic, it could use the UTXO set space more
efficiently, especially if your goal is to prioritise bitcoin value-transfer
over other uses (though if "normal" wallets nearly never need to use TXO
commitments proofs to spend outputs, the infrastructure to actually do this may

3) Should UTXO archiving be based on a fixed size UTXO set, rather than an
age/priority/etc. threshold?

4) By fixing the problem (or possibly just "fixing" the problem) are we
encouraging/legitimising blockchain use-cases other than BTC value transfer?
Should we?

5) Instead of TXO commitment proofs counting towards the blocksize limit, can
we use a different miner fairness/decentralization metric/incentive? For
instance it might be reasonable for the TXO commitment proof size to be
discounted, or ignored entirely, if a proof-of-propagation scheme (e.g.
thinblocks) is used to ensure all miners have received the proof in advance.

6) How does this interact with fraud proofs? Obviously furthering dependency on
non-cryptographically-committed STXO/UTXO databases is incompatible with the
modularized validation approach to implementing fraud proofs.

# References

1) "Merkle Mountain Ranges",
Peter Todd, OpenTimestamps, Mar 18 2013,

2) "Do we really need a mempool? (for relay nodes)",
Peter Todd, bitcoin-dev mailing list, Jul 18th 2015,

3) "Segregated witnesses and validationless mining",
Peter Todd, bitcoin-dev mailing list, Dec 23rd 2015,

-- 'peter'[:-1]
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Welcome to the FLO subreddit! Here you can learn about FLO and its use as a worldwide public record in many blockchain-based applications

FLO: a worldwide public record

What is FLO?
FLO is a cryptocurrency that introduces a worldwide public record for storing information. FLO coins are needed to pay for storage capacity, and coins are issued to reward participants for their work to secure and distribute information.
FLO is used to send payments and store data. This encourages building applications because anyone has the ability to write data into FLO.
How does FLO work?
FLO is a network similar to bitcoin where the open ledger is secured by miners competing to find proof-of-work. FLO has its own ledger, called the FLO blockchain, that can be thought of as a digital public space for storing information.

Release files


Technical Specifications

Block target spacing: 40 seconds
Difficulty retargets every blocks
Block reward: 100 FLO, halving every 800,000 blocks (about 1 year)
Maximum coins: 160 million FLONetwork port: 7312RPC port: 7313

Mining Information

See our mining guide here:

Block explorers


Indacoin Exchange
Coin swap services


Alexandria Rocket Chat
Medium Blog
IRC channel Join #florincoin on
FLO Slack


Notable Partnerships:

California Institute of Technology-
Overstock's tZERO -
Open Index Protocol Working Group- /
Medici Ventures-

Apps running on top of the FLO blockchain:
OIP apps
Open Index Protocol -
Alexandria -
California Institute of Technology -
Medici Ventures -
Block Header -
FLO native apps
Overstock's tZERO -
Shared Secret -
Notarize with Flotorizer -
World Mood -
Aterna Love - -


Official web site
Github links for Alexandria, OIP, Ranchi, and FLO
FLO Foundation
Florincoin and Alexandria presentation @ BitDevs NYC 5/24/17
Florincoin @ CryptoCurrency Convention NYC 4/9/14
Florin article @ bitcoinist
Blockchain bootstrap from!u15HSADT!nstJ67-mKnWZbMPwddeRJoxEnNneS_94yTfLHoeNQyg
FLO market data read from FLO blockchain visualised
The Decentralized Library of Alexandria - San Diego Bitcoin Meetup 08/15
Blocktech Project Alexandria v0.4 alpha Intro and Walkthrough
Alexandria v0.5.1 alpha demo
FLO History
Launched June 17th 2013, the first coin with a metadata field on the blockchain for the purpose of building blockchain applications.
2013 * Jun 17th: FLO released with no pre-mine and no ICO * Jul 9th: Florincoin is the 61st coin added to Cryptsy, the first major altcoin exchange * Sep 9th: Created the first block explorer,, an open source explorer which is later replaced with * Nov 27th: Coordinated with Skyangel on a hard-fork (required update) to increase the transaction comment size to 528 bytes * Dec 10th: Started work on new website * Dec 16th: Songs of Love, a charity for children based in NYC, beings accepting FLO donations to make customized songs for children in need
2014 * Feb 1st: Created the FLO twitter account (Originally @Official_Florin) * Feb 1st: Created a website, Aterna Love, to store valentine's day messages in the blockchain. Those messages still exist today * Feb 12th: Promoted FLO at the bitcoin center in NYC, with interview by Naomi Brockwell * Mar 2nd: Launched new website * Mar 20th: Florincoin subreddit created (originally /florincoin) * Apr 9th: Presentation about Florincoin at the 1st Cryptocurrency Convention at the scholastic auditorium in NYC * Apr 12th: skyangel releases Florin v0.6.5.13, a hard fork at block 426000, causing FLO to start adjusting difficulty every block * Jun 21st: skyangel releases Florin v0.8.7.2, up to date with the latest Litecoin codebase * Jun 22nd: article: exclusive Q&A with Joseph Fiscella * Sep 20th: Alexandria team meets in San Diego to work on the project as a team for the first time * Oct 4th: Inside Bitcoins Las Vegas conference with the Alexandria Booth
2015 * Jan 1st: FLO and Alexandria mentioned in a chapter about blockchain applications in Melanie Swan's book Blockchain: A Blueprint for a New Economy * Mar 3rd: Released the first golang SDK for Florincoin, foundation, on github: - - * Mar 11th: FLO is open for trading on Bittrex * Mar 11th: FLO is open for trading on Poloniex * Apr 17th: Alexandria 0.4 walkthrough video: * Jun 10th: interview with Alexandria * Jun 25th: Alexandria historian is born and begins recording historic data on the blockchain * Jun 29th: VICE article about Alexandria released: Could Cyberwar Cause a Library of Alexandria Event? * Aug 5th: LA times article about Blockchain Technology Group / Alexandria * Sep 24th: CoinTelegraph article about Alexandria * Dec 9th: Alexandria v0.5.1 alpha demo * Dec 16th: Alexandria booth at Inside Bitcoins San Diego
2016 * Mar 25th: FLO released by Bitspill and the Alexandria team, as well as a pool mining historian blocks * Apr 8th: FLO used to store Libertarian Party votes in blockchain * May 3rd: Alexandria meetup in NYC (video URL missing) * Jun 19th: FLO recommended update to latest Litecoin codebase * Nov 27: Alexandria presentation at DAppHack Berlin 2016
2017 * May 15th: FLO meetup in NYC, Telegram channel created * May 25th: FLO/Alexandria presentation lived streamed from BitDevs NYC: * July 12th: Introducing Alexandria and the Open Index Protocol * July 28th: Amy's blog post about the Alexandria team's visit to San Diego * Aug 20th: Valentin Jesse creates a FLO touchbar app for the 2017 MacBookPro * Nov 29th: New logo and new website concept released and revealed to community in the rebranding initiative * Dec 22nd: New website launched: * Dec 22nd: Flotorizer launched at, Medium article written by Davi Ortega describing the creation of a FLO blockchain application as a non-programmer * Dec 24th: FLO Community Update * Dec 31st:, the first blockchain-based implementation of Shamir's Secret Sharing algorithm, is live (again created by Davi Ortega)
2018 * Jan 13th: Live-streaming FLO dev on * Jan 18th: FLO python SDK released * Jan 18th: FLO added to brainwalletX * Jan 18th: FLO C# SDK released * Feb 23th: FLO partners with YBF Ventures * Mar 20th: FLO releases version 0.15 with segwit support, up-to-date with current Bitcoin and Litecoin codebases: * May 1st: SPV wallet floj is open-sourced by Alexandria and Medici teams * July 17th: FLO summit 2018 held in San Diego * July 26th: Website updated with dapps dashboard
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Man buys $27 of bitcoin, forgets about them, finds they're now worth $886k | Technology

This is an automatic summary, original reduced by 61%.
Typically bitcoins are bought using traditional currency from a bitcoin "Exchanger", although due to strict anti-money laundering controls, the process can can be tricky.
A user can then withdraw those bitcoins by sending them back to an exchanger like Mt Gox, the best known bitcoin exchange, in return for cash.
It is now possible to actually spend bitcoins without exchanging them for traditional currency first in a few British pubs, including the Pembury Tavern in Hackney, London, for instance.
On 29 October, the world's first bitcoin ATM also went online in Vancouver, Canada, which scans a user's palm before letting them buy or sell bitcoins for cash.
A small group of hardcore users also generate extra bitcoins by "Mining" for them - a process that requires computers to perform the calculations needed to make the digital currency work, in exchange for a share of the built-in inflation.
In August, Germany recognised bitcoin as a "Unit of account", allowing the country to tax users or creators of the digital currency.
Summary Source | FAQ | Theory | Feedback | Top keywords: bitcoin#1 currency#2 exchanged#3 more#4 Koch#5
Post found in /Bitcoin, /BitcoinAll, /news and /todayilearned.
NOTICE: This thread is for discussing the submission topic. Please do not discuss the concept of the autotldr bot here.
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Segregated witnesses and validationless mining | Peter Todd | Dec 23 2015

Peter Todd on Dec 23 2015:


1) Segregated witnesses separates transaction information about what
coins were transferred from the information proving those transfers were
2) In its current form, segregated witnesses makes validationless mining
easier and more profitable than the status quo, particularly as
transaction fees increase in relevance.
3) This can be easily fixed by changing the protocol to make having a
copy of the previous block's (witness) data a precondition to creating a


Why should a miner publish the blocks they find?

Suppose Alice has negligible hashing power. She finds a block. Should
she publish that block to the rest of the hashing power? Yes! If she
doesn't publish, the rest of the hashing power will build a longer chain
than her chain, and she won't be rewarded. Right?
Well, can other miners build on top of Alice's block? If she publishes
nothing at all, the answer is certainely no - block headers commit to
the previous block's hash, so without knowing at least the hash of
Alice's block other miners can't build upon it.

Validationless mining

Suppose Bob knows the hash of Alice's new block, as well as the height
of it. This is sufficient information for Bob to create a new, valid,
block building upon Alice's block. The hash is needed because of the
prevhash field in the block header; the height is needed because the
coinbase has to contain the block height. (technically he needs to know
nTime as well to be 100% sure he's satisfying the median time rule) What
Bob is doing is validationless mining: he hasn't validated Alice's
block, and is assuming it is valid.
If Alice runs a pool her stratum or getblocktemplate interfaces give
sufficient information for Bob to figure all this out. Miners today take
advantage of this to reduce their orphan rates - the sooner you can
start mining on top of the most recently found block the more money you
earn. Pools have strong incentives to only publish work that's valid to
their hashers, so as long as the target pool doesn't know who you are,
you have high assurance that the block hash you're building upon is
Of course, when this goes wrong it goes very wrong, greatly amplifying
the effect of 51% attacks and technical screwups, as seen by the July
4th 2015 chain fork, where a majority of hashing power was building on
top of an invalid block.


However other than coinbase transactions, validationless mined blocks
are nearly always empty: if Bob doesn't know what transactions Alice
included in her block, he doesn't know what transaction outputs are
still unspent and can't safely include transactions in his block. In
short, Bob doesn't know what the current state of the UTXO set is. This
helps limit the danger of validationless mining by making it visible to
everyone, as well as making it not as profitable due to the inability to
collect transaction fees. (among other reasons)

Segregated witnesses and validationless mining

With segregated witnesses the information required to update the UTXO
set state is now separate from the information required to prove that
the new state is valid. We can fully expect miners to take advantage of
this to reduce latency and thus improve their profitability.
We can expect block relaying with segregated witnesses to separate block
propagation into four different parts, from fastest to propagate to
1) Stratum/getblocktemplate - status quo between semi-trusting miners
2) Block header - bare minimum information needed to build upon a block.
Not much trust required as creating an invalid header is expensive.
3) Block w/o witness data - significant bandwidth savings, (~75%) and
allows next miner to include transactions as normal. Again, not much
trust required as creating an invalid header is expensive.
4) Witness data - proves that block is actually valid.
The problem is #4 is optional: the only case where not having the
witness data matters is when an invalid block is created, which is a
very rare event. It's also difficult to test in production, as creating
invalid blocks is extremely expensive - it would be surprising if an
anyone had ever deliberately created an invalid block meeting the
current difficulty target in the past year or two.

The nightmare scenario - never tested code ~never works

The obvious implementation of highly optimised mining with segregated
witnesses will have the main codepath that creates blocks do no
validation at all; if the current ecosystem's validationless mining is
any indication the actual code doing this will be proprietary codebases
written on a budget with little testing, and lots of bugs. At best the
codepaths that actually do validation will be rarely, if ever, tested in
Secondly, as the UTXO set can be updated without the witness data, it
would not be surprising if at least some of the wallet ecosystem skips
witness validation.
With that in mind, what happens in the event of a validation failure?
Mining could continue indefinitely on an invalid chain, producing blocks
that in isolation appear totally normal and contain apparently valid
transactions. It's easy to imagine this happening from an engineering
perspective: a simple implementation would be to have the main mining
codepaths be a separate, not-validating, process that receives "invalid
block" notifications from another process containing a validating
implementation of the Bitcoin protocol. If a bug/exploit is found that
causes that validation process to crash, what's to guarantee that the
block creation codepath will even notice? Quite likely it will continue
creating blocks unabated - the invalid block notification codepath is
never tested in production.

Easy solution: previous witness data proof

To return segregated witnesses to the status quo, we need to at least
make having the previous block's witness data be a precondition to
creating a block with transactions; ideally we would make it a
precondition to making any valid block, although going this far may
receive pushback from miners who are currently using validationless
mining techniques.
We can require blocks to include the previous witness data, hashed with
a different hash function that the commitment in the previous block.
With witness data W, and H(W) the witness commitment in the previous
block, require the current block to include H'(W)
A possible concrete implementation would be to compute the hash of the
current block's coinbase txouts (unique per miner for obvious reasons!)
as well as the previous block hash. Then recompute the previous block's
witness data merkle tree (and optionally, transaction data merkle tree)
with that hash prepended to the serialized data for each witness.
This calculation can only be done by a trusted entity with access to all
witness data from the previous block, forcing miners to both publish
their witness data promptly, as well as at least obtain witness data
from other miners. (if not actually validate it!) This returns us to at
least the status quo, if not slightly better.
This solution is a soft-fork. As the calculation is only done once per
block, it is not a change to the PoW algorithm and is thus compatible
with existing minehasher setups. (modulo validationless mining
optimizations, which are no longer possible)

Proofs of non-inflation vs. proofs of non-theft

Currently full nodes can easily verify both that inflation of the
currency has no occured, as well as verify that theft of coins through
invalid scriptSigs has not occured. (though as an optimisation currently
scriptSig's prior to checkpoints are not validated by default in Bitcoin
It has been proposed that with segregated witnesses old witness data
will be discarded entirely. This makes it impossible to know if miner
theft has occured in the past; as a practical matter due to the
significant amount of lost coins this also makes it possible to inflate
the currency.
How to fix this problem is an open question; it may be sufficient have
the previous witness data proof solution above require proving posession
of not just the n-1 block, but a (random?) selection of other previous
blocks as well. Adding this to the protocol could be done as soft-fork
with respect to the above previous witness data proof.

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13 december Asic Miners Review How to build a Mining Rig - Teil 1 - Die Hardware Deutsch Bitcoin Mining - YouTube Bitcoin Mining Software of 2019 4 BTC online 👍 - YouTube bitcoin mining calculator

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