Eauto Prämie Tageszulassung » Blogtotal

Jouke Hofman treedt uit bestuur Stichting Bitcoin Nederland

Jouke Hofman treedt uit bestuur Stichting Bitcoin Nederland submitted by AaronVanWirdum to BitcoinNL [link] [comments]

"Capacity Increase" signatories list

Out of curiosity, I wanted to know who the list of signatures were other than just names on a list. I went through each profile and did my best to align them to their known public company. If it's unknown or independent, I listed them as unknown.
Notes:
source: https://bitcoin.org/en/bitcoin-core/capacity-increases
submitted by Gobitcoin to btc [link] [comments]

Bitcoin dev IRC meeting in layman's terms (2015-11-05)

Once again my attempt to summarize and explain the weekly bitcoin developer meeting in layman's terms. Link to last weeks summarization
On a personal note: I really don't like the fact someone pm'ed me telling me "a majority of bitcoiners have moved to btc", it's not (yet) true and comes across as very spammy. This combined with the tin-foiled hat people-bashing which seems to be popular makes me almost not want to join this community. I hope this can become like bitcoin, but with the freedom to discuss and mention any topic, not a mindless crusade against bitcoin, theymos, blockstream, etc.
Disclaimer
Please bear in mind I'm not a developer and I'd have problems coding "hello world!", so some things might be incorrect or plain wrong. Like any other write-up it likely contains personal biases, although I try to stay as neutral as I can. There are no decisions being made in these meetings, so if I say "everyone agrees" this means everyone present in the meeting, that's not consensus, but since a fair amount of devs are present it's a good representation. The dev IRC and mailinglist are for bitcoin development purposes. If you have not contributed actual code to a bitcoin-implementation, this is probably not the place you want to reach out to. There are many places to discuss things that the developers read, including this sub-reddit.
link to this week logs Meeting minutes by meetbot
Main topics discussed where:
Sigcache performance Performance goals for 0.12 transaction priority sigops flooding attack chain limits
Short topics/notes
Note: cfields, mcelrath and BlueMatt (and maybe more) missed the meeting because of daylight saving time.
Closing date for proposals for the scaling bitcoin workshop is the 9th.
Check to see if there are any other commits for the 0.11.2 RC. As soon as 6948 and 6825 are merged it seems good to go. We need to move fairly quick as there are already miners voting for CLTV (F2Pool). Also testnet is CLTV locked already and is constantly forking. 0.11.2 RC1 has been released as of today: https://bitcoin.org/bin/bitcoin-core-0.11.2/test/
Most of the mempool-limiting analysis assumed child-pays-for-parent, however that isn't ready for 0.12 yet, so we should think about possible abuses in context of the existing mining algorithm.
Because of time-constrains opt-in replace-by-fee has been deferred to next weeks meeting, but most people seem to want it in 0.12. sdaftuar makes a note that we need to make clear to users what they need to do if they don't want to accept opt-in transactions.
Sigcache performance
The signature cache, which is in place to increase performance (by not having to check the signature multiple times), and to mitigate some attacks currently has a default limit of 50 000 signatures. Sipa has a pull-request which proposes to: Change the limit from number of entries to megabytes Change the default to 40MB, which corresponds to 500 000 signatures Store salted hashes instead of full entries Remove entries that have been validated in a block
Sipa did benchmarks for various signature cache sizes on hitrate in blocks (how many of the cached signatures are in the block). The maximum sigcache size was 68MB, resulting in a 3% miss-rate. Some blocks though have extremely high miss rates (60%) while others have none. Likely caused by miners running different policies. Gmaxwell proposed to always run script verification for mempool transactions, even if these transactions get rejected into the mempool by the clients policy. The result of that is that even a 300MB sigcache size only gets down to 15% misses. So there's too much crap being relayed to keep any reasonable sized cache. Gmaxwell points out downsides to not checking any rejected transactions, namely: there are some DOS attacks possible, and you increase your misrate if you set a policy which is more restrictive than the typical network, which might result in a race to the bottom.
Sipa continues his work and seeks out other strategies
Performance goals for 0.12
Bitcoin-core 0.12 is scheduled for release December 1st.
Everybody likes to include secp256k1 ASAP, as it has a very large performance increase. Some people would like to include the sigcache pull-request, BIP30, modifyNewCoins and a createNewBlock rewrite if it's ready. Wumpus advises against merging last-minute performance improvements for 0.12.
Mentioned pull-requests should be reviewed, prioritizing CreateNewBlock
transaction priority
Each transaction is assigned a priority, determined by the age, size, and number of inputs. Which makes some transactions free.
Sipa thinks we should get rid of the current priority completely and replace it with a function that modifies fee or size of a transaction. There's a pull-request available that optimizes the current transaction priority, thereby avoiding the political debate that goes with changing the definition of transaction priority. Luke-jr thinks the old policy should remain possible.
Check to see if PR #6357 is safe and efficient enough.
sigops flooding attack
The number of ECDSA signature-checking operations or sigops is currently limited to 20 000 per block. This in order to prevent miners creating blocks that take ages to verify as those operations are time-consuming. You could however construct transactions that have a very high sigops count and since most miners don't take into account the sigops count they end up with very small blocks because the sigop limit is reached. This attack is described here.
Suggestion to take the number of sigops relative to the maximum blocksize into account with the total size. Meaning a 10k sigops transaction would currently be viewed as 500kB in size (for that single transaction, not towards the block). That suggestion would be easy to change in the mining code, but more invasive to try and plug that into everything that looks at feerate. This would also open up attacks on the mempool if these transactions are not evicted by mempool limiting. Luke-jr has a bytes-per-sigop limit, that filters out these attack transactions.
More analysis should be done, people seem fine with the general direction of fixing it.
chain limits
Chain in this context means connected transactions. When you send a transaction that depends on another transaction that has yet to be confirmed we talk about a chain of transactions. Miners ideally take the whole chain into account instead of just every single transaction (although that's not widely implemented afaik). So while a single transaction might not have a sufficient fee, a depending transaction could have a high enough fee to make it worthwhile to mine both. This is commonly known as child-pays-for-parent. Since you can make these chains very big it's possible to clog up the mempool this way. With the recent malleability attacks, anyone who made transactions going multiple layers deep would've already encountered huge problems doing this (beautifully explained in let's talk bitcoin #258 from 13:50 onwards) Proposal and github link.
sdaftuar's analysis shows that 40% of blocks contain a chain that exceeds the proposed limits. Even a small bump doesn't make the problem go away. Possible sources of these chains: a service paying the fees on other transactions (child-pays-for-parent), an iOS wallet that gladly spends unconfirmed change. A business confirms they use child-pays-for-parent when they receive bitcoins from an unspent chain. It is possible that these long chains are delivered to miners directly, in which case they wouldn't be affected by the proposed relay limits (and by malleability). Since this is a problem that needs to be addressed, people seem fine with merging it anyway, communicating in advance to let businesses think about how this affects them.
Merge "Policy: Lower default limits for tx chains" Morcos will mail the developer mailing list after it's merged.
Participants
morcos Alex Morcos gmaxwell Gregory Maxwell wumpus Wladimir J. van der Laan sipa Pieter Wuille jgarzik Jeff Garzik Luke-Jr Luke Dashjr phantomcircuit Patrick Strateman sdaftuar Suhas Daftuar btcdrak btcdrak jouke ??Jouke Hofman?? jtimon Jorge Timón jonasschnelli Jonas Schnelli 
Comic relief
20:01 wumpus #meetingend 20:01 wumpus #meetingstop 20:01 gmaxwell Thanks all. 20:01 btcdrak #exitmeeting 20:01 gmaxwell #nomeetingnonono 20:01 btcdrak #meedingexit 20:01 wumpus #endmeeting 20:01 lightningbot Meeting ended Thu Nov 5 20:01:29 2015 UTC. Information about MeetBot at http://wiki.debian.org/MeetBot . 20:01 btcdrak #rekt 
submitted by G1lius to btc [link] [comments]

Bitcoin dev IRC meeting in layman's terms (2015-11-05)

Once again my attempt to summarize and explain the weekly bitcoin developer meeting in layman's terms. Link to last weeks summarization Note that I crosspost this to Voat, bitcoin.com and the bitcoin-discuss mailing list every week. I can't control what's being talking about in the meeting, if certain things come up I might not be able to post here because of "guidelines".
Disclaimer
Please bear in mind I'm not a developer and I'd have problems coding "hello world!", so some things might be incorrect or plain wrong. Like any other write-up it likely contains personal biases, although I try to stay as neutral as I can. There are no decisions being made in these meetings, so if I say "everyone agrees" this means everyone present in the meeting, that's not consensus, but since a fair amount of devs are present it's a good representation. The dev IRC and mailinglist are for bitcoin development purposes. If you have not contributed actual code to a bitcoin-implementation, this is probably not the place you want to reach out to. There are many places to discuss things that the developers read, including this sub-reddit.
link to this week logs Meeting minutes by meetbot
Main topics discussed where:
Sigcache performance Performance goals for 0.12 transaction priority sigops flooding attack chain limits
Short topics/notes
Note: cfields, mcelrath and BlueMatt (and maybe more) missed the meeting because of daylight saving time.
Closing date for proposals for the scaling bitcoin workshop is the 9th.
Check to see if there are any other commits for the 0.11.2 RC. As soon as 6948 and 6825 are merged it seems good to go. We need to move fairly quick as there are already miners voting for CLTV (F2Pool). Also testnet is CLTV locked already and is constantly forking. 0.11.2 RC1 has been released as of today: https://bitcoin.org/bin/bitcoin-core-0.11.2/test/
Most of the mempool-limiting analysis assumed child-pays-for-parent, however that isn't ready for 0.12 yet, so we should think about possible abuses in context of the existing mining algorithm.
Because of time-constrains opt-in replace-by-fee has been deferred to next weeks meeting, but most people seem to want it in 0.12. sdaftuar makes a note that we need to make clear to users what they need to do if they don't want to accept opt-in transactions.
Sigcache performance
The signature cache, which is in place to increase performance (by not having to check the signature multiple times), and to mitigate some attacks currently has a default limit of 50 000 signatures. Sipa has a pull-request which proposes to: Change the limit from number of entries to megabytes Change the default to 40MB, which corresponds to 500 000 signatures Store salted hashes instead of full entries Remove entries that have been validated in a block
Sipa did benchmarks for various signature cache sizes on hitrate in blocks (how many of the cached signatures are in the block). The maximum sigcache size was 68MB, resulting in a 3% miss-rate. Some blocks though have extremely high miss rates (60%) while others have none. Likely caused by miners running different policies. Gmaxwell proposed to always run script verification for mempool transactions, even if these transactions get rejected into the mempool by the clients policy. The result of that is that even a 300MB sigcache size only gets down to 15% misses. So there's too much crap being relayed to keep any reasonable sized cache. Gmaxwell points out downsides to not checking any rejected transactions, namely: there are some DOS attacks possible, and you increase your misrate if you set a policy which is more restrictive than the typical network, which might result in a race to the bottom.
Sipa continues his work and seeks out other strategies
Performance goals for 0.12
Bitcoin-core 0.12 is scheduled for release December 1st.
Everybody likes to include secp256k1 ASAP, as it has a very large performance increase. Some people would like to include the sigcache pull-request, BIP30, modifyNewCoins and a createNewBlock rewrite if it's ready. Wumpus advises against merging last-minute performance improvements for 0.12.
Mentioned pull-requests should be reviewed, prioritizing CreateNewBlock
transaction priority
Each transaction is assigned a priority, determined by the age, size, and number of inputs. Which makes some transactions free.
Sipa thinks we should get rid of the current priority completely and replace it with a function that modifies fee or size of a transaction. There's a pull-request available that optimizes the current transaction priority, thereby avoiding the political debate that goes with changing the definition of transaction priority. Luke-jr thinks the old policy should remain possible.
Check to see if PR #6357 is safe and efficient enough.
sigops flooding attack
The number of ECDSA signature-checking operations or sigops is currently limited to 20 000 per block. This in order to prevent miners creating blocks that take ages to verify as those operations are time-consuming. You could however construct transactions that have a very high sigops count and since most miners don't take into account the sigops count they end up with very small blocks because the sigop limit is reached. This attack is described here.
Suggestion to take the number of sigops relative to the maximum blocksize into account with the total size. Meaning a 10k sigops transaction would currently be viewed as 500kB in size (for that single transaction, not towards the block). That suggestion would be easy to change in the mining code, but more invasive to try and plug that into everything that looks at feerate. This would also open up attacks on the mempool if these transactions are not evicted by mempool limiting. Luke-jr has a bytes-per-sigop limit, that filters out these attack transactions.
More analysis should be done, people seem fine with the general direction of fixing it.
chain limits
Chain in this context means connected transactions. When you send a transaction that depends on another transaction that has yet to be confirmed we talk about a chain of transactions. Miners ideally take the whole chain into account instead of just every single transaction (although that's not widely implemented afaik). So while a single transaction might not have a sufficient fee, a depending transaction could have a high enough fee to make it worthwhile to mine both. This is commonly known as child-pays-for-parent. Since you can make these chains very big it's possible to clog up the mempool this way. With the recent malleability attacks, anyone who made transactions going multiple layers deep would've already encountered huge problems doing this (beautifully explained in let's talk bitcoin #258 from 13:50 onwards) Proposal and github link.
sdaftuar's analysis shows that 40% of blocks contain a chain that exceeds the proposed limits. Even a small bump doesn't make the problem go away. Possible sources of these chains: a service paying the fees on other transactions (child-pays-for-parent), an iOS wallet that gladly spends unconfirmed change. A business confirms they use child-pays-for-parent when they receive bitcoins from an unspent chain. It is possible that these long chains are delivered to miners directly, in which case they wouldn't be affected by the proposed relay limits (and by malleability). Since this is a problem that needs to be addressed, people seem fine with merging it anyway, communicating in advance to let businesses think about how this affects them.
Merge "Policy: Lower default limits for tx chains" Morcos will mail the developer mailing list after it's merged.
Participants
morcos Alex Morcos gmaxwell Gregory Maxwell wumpus Wladimir J. van der Laan sipa Pieter Wuille jgarzik Jeff Garzik Luke-Jr Luke Dashjr phantomcircuit Patrick Strateman sdaftuar Suhas Daftuar btcdrak btcdrak jouke ??Jouke Hofman?? jtimon Jorge Timón jonasschnelli Jonas Schnelli 
Comic relief
20:01 wumpus #meetingend 20:01 wumpus #meetingstop 20:01 gmaxwell Thanks all. 20:01 btcdrak #exitmeeting 20:01 gmaxwell #nomeetingnonono 20:01 btcdrak #meedingexit 20:01 wumpus #endmeeting 20:01 lightningbot Meeting ended Thu Nov 5 20:01:29 2015 UTC. Information about MeetBot at http://wiki.debian.org/MeetBot . 20:01 btcdrak #rekt 
submitted by G1lius to Bitcoin [link] [comments]

Dutch Bitcoin Foundation: Bitcoin-seminar: 3 sept. (03:00 - 05:00pm) @ Pakhuis de Zwijger, A'dam

On 3 September from 03:00 until 05:00 PM the Dutch Bitcoin Foundation is organizing a seminar with a focuses on the technology, the facts and the science of Bitcoin.
In this two-hour seminar, Jouke Hofman will take you into the world of Bitcoin. The challenge is to explain this highly innovative phenomenon in an understandable way. Jouke gives more substantive seminars to financial institutions, government agencies and other organizations with the aim of increasing the understandability of Bitcoin.
The following topics are covered: 1 Introduction (What is Bitcoin and facts) 2 How Bitcoin work: - Bitcoin addresses - Transactions - Mining - Future 3. Abuse 4 The underground 5. Trade
Register?
!! From 19:00 the Bitcoin Wednesday
submitted by daan_btc to Bitcoin [link] [comments]

Bitcoin whitepaper – 10 years – Amsterdam celebration GamersNET - YouTube Interview Jouke Hofman - General Manager at Bitonic @ Dutch Blockchain Hackathon kick-off Gefahr am Geldautomaten: Die neuesten Tricks der Betrüger ... #Bitcoin2014 - Panel: Technical Possibilities of Bitcoin Exchanges

Frank Beckenbach & Maria Daskalakis & David Hofmann, 2018. " ... "News and subjective beliefs: A Bayesian approach to Bitcoin investments," Research in International Business and Finance, Elsevier, vol. 50(C), pages 336-356. Srikanth Paruchuri & Atul Nerkar & Donald C. Hambrick, 2006. "Acquisition Integration and Productivity Losses in the Technical Core: Disruption of Inventors in Acquired ... Internet & Technology News Binance says more than $40 million in bitcoin stolen in ‘large scale’ hack Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for. Bitcoin mining causes about 22 million tons of CO2 annually – comparable to the emissions of cities such as Hamburg or Las Vegas. This was the conclusion of a detailed analysis of the cryptocurrency’s carbon footprint by researchers of TUM and MIT. In their new study, the interdisciplinary team of researchers looked at the energy demand of more than 500 further mineable coins and tokens ... Autohaus Hofmann Forchheim – Renault &am… Textausschnitt: Autohaus Hofmann Forchheim – Renault & Dacia Vertragswerkstatt, EU Neuwagen, Jahreswagen und Tageszulassungen Renault Megane Kombi GT-Line dCi 130 …

[index] [5024] [8866] [26445] [18632] [45406] [44972] [3326] [44126] [29883] [36318]

Bitcoin whitepaper – 10 years – Amsterdam celebration

Eindeloze discussies over bubbels en Piramidespellen op werk! Wees niet te sceptisch en wees niet te laat! Laat ons weten wat jij denkt over Bitcoin en de crypromarkt! Laat een comment achter en ... The potential use-cases are so huge so it’s really nice to see all these companies included in this programme. Everybody nowadays knows about bitcoin, three years ago it was totally different ... Cryptocurrency 24 januari 2018 Vaste commissie voor Financiën Rondetafelgesprek Mw De Haas vereniging bitcoin bedrijven nl Jouke Hofman bitonic Thomas Bijl follow coin Niels Lemme veb http ... Jouke Hofman is the General Manager of Bitonic. Starting in 2012 Bitonic nowadays is the largest Bitcoin company in The Netherlands. You can easily buy and sell Bitcoins and euro's using iDeal ... Bitcoin 2014's Bitcoin Technology: Present and Future's Panel: Technical Possibilities of Bitcoin Exchanges took place on Friday, May 16, 2014 at the Movenpick Hotel - Zurich 2 from 12:00pm-1:00pm ...

#