A Greener Cryptocurrency From Bittorrent Inventor, Bram Cohen

Fifty Years of Cypherpunk: History, Personalities, And Spread of its ideas

In this review, we tell how the ideas of cypherpunk were born, how they influenced cryptocurrencies, and modern technologies, who formed the basis and why its popularity these days has grown again.

From the early days to today: the chronology of key events of the cypherpunk

In the early 1970s, James Ellis of the UK Government Communications Center put forward the concept of public-key cryptography. In the early 1980s, small groups of hackers, mathematicians and cryptographers began working on the realization of this idea. One of them was an American cryptographer, Ph.D. David Chaum, who is sometimes called the godfather of cypherpunk. This new culture has proclaimed computer technology as a means of destroying state power and centralized management systems.Key figure among the cypherpunk of the 80s — Intel specialist Timothy C. May. His dream was to create a global system that allows anonymous exchange of information. He created the concept of the BlackNet system. In September 1988, May wrote The Crypto-Anarchist Manifesto: people themselves, without politicians, manage their lives, use cryptography, use digital currencies, and other decentralized tools.In 1989, David Chaum founded DigiCash an eCash digital money system with its CyberBucks and with the blind digital signature technology.Since 1992, Timothy May, John Gilmore (Electronic Frontier Foundation), and Eric Hughes (University of California) have begun holding secret meetings and regular PGP-encrypted mailing through anonymous remailer servers. And finally, in 1993 Eric Hughes published a fundamental document of the movement — А Cypherpunk's Manifesto. The importance of confidentiality, anonymous transactions, cryptographic protection — all these ideas were subsequently implemented in cryptocurrencies.The term "cypherpunk" was first used by hacker and programmer Jude Milhon to a group of crypto-anarchists.In 1995, Julian Assange, the creator of WikiLeaks, published his first post in cypherpunk mailing.In 1996, John Young and Deborah Natsios created the Cryptome, which published data related to security, privacy, freedom, cryptography. It is here that subsequently will be published data from the famous Edward Snowden.In 1997, cryptographer Dr. Adam Back (you know him as CEO of Blockstream) created Hashcash, a distributed anti-spam mechanism.In 1998, computer engineer Wei Dai published two concepts for creating a b-money digital payment system:
In April 2001, Bram Cohen developed the BitTorrent protocol and application.In 2002, Paul Syverson, Roger Dingledine and Nick Mathewson presented the alpha version of the anonymity network named TOR Project.In 2004, cypherpunk Hal Finney created the Reusable Proof of Work (RPoW) algorithm. It was based on Adam Back's Hashcash but its drawback was centralization.In 2005, cryptographer Nick Szabo, who developed the concept of smart contracts in the 1990s, announced the creation of Bit Gold — a digital collectible and investment item.In October 2008, legendary Satoshi Nakamoto created the manifesto “Bitcoin: A Peer-to-Peer Electronic Cash System”, which refers to the works of the cypherpunk classics Adam Back and Wei Dai.In 2011, Ross William Ulbricht aka Dread Pirate Roberts created the Silk Road, the first major market for illegal goods and services on the darknet.In 2016, Julian Assange released the book "Cypherpunks: Freedom and the future of the Internet."At the beginning of 2018, Pavel Durov, the creator of Telegram, announced the launch of the TON multi-blockchain platform and mentioned his plans to launch TON ICO.In 2019, the Tor Project‌ introduced an open anti-censorship group.

Cypherpunk 2020

Plenty of services, products, and technologies were inspired by cypherpunk: Cryptocurrencies, HD (Hierarchical Deterministic) crypto wallets, Coin Mixers, ECDHM addresses, Privacy Coins. The ideas of distribution and anonymity were also implemented in the torrents and VPN. You can see the embodiment of cybersecurity ideas in the electronic signatures and protected messengers (Telegram, Signal, and many others).Why there were so many talks about cypherpunk this spring? In April 2020, Reddit users suggested that the letter from the famous cypherpunks mailing dated September 19, 1999, was written by Satoshi Nakamoto himself (or someone close to him). This letter is about the functioning of ecash. Anonymous (supposed Satoshi) talks about the "public double-spending database" and Wei Dai's b-money as a possible foundation for ecash.In addition, researchers of the mystery "Who is Satoshi Nakamoto?" periodically make some noise and discover the next "secret" about one or another legendary cypherpunks. So, in May 2020, Adam Back wrote in response to videos and new hype discussions that, despite some coincidences, he is not Satoshi.Other heroes of the scene are not idle too: in April 2020, David Chaum received $9.7 million during the presale of the confidential coin xx, created to encourage venture investors.

Conclusion

As you can see from the Satoshi Nakamoto's mentions and from the stories of DigiCash, Hashcash, RPoW, Bit Gold, the movement of cypherpunk influenced a lot the emergence of cryptocurrencies. As governments and corporations restrict freedom and interfere with confidentiality, cypherpunk ideas will periodically rise in popularity. And this confrontation will not end in the coming decades.
submitted by CoinjoyAssistant to bitcoin_uncensored [link] [comments]

Amir Taaki - Breaking Bitcoin presentation (transcript)

Below I transcribed Amir's talk from Breaking Bitcoin (see previous post here, start of presentation (youtube): here). Excuse the errors (will fix if you point me to them).
What was most interesting for me:
Amir:
Thank you for having me here.
I believe that ideas play an important role in shaping human history. What I want to talk about is how technology has been shaped by key ideas. In particular how certain mechanical ideas of human society got mixed up with with politics and technology.
What I want to talk about is the free technology movement. It was a movement that showed great potential promise to liberate humanity. At the heart of it was a idea that technology offered a new way to construct a radially different kind of society that never before was possible in history, this movement was influenced by the visions of early scientists who believed in the power of computer technology not just to serve large industry and military but everybody to have access to this new power.
Influenced of by the 60s counterculture, this movement went on to develop the first personal computers. But that's not the end of the story because this radical vision mutated into the idea of self-regulating systems which see human beings as object managed by computer algorithms. In this vision, the value of human ideas to transform the world was diminished into a strange kind of consensus where everybody satisfies their personal desires.
We now find ourselves in a strange static dreamworld while dark forces are returning to threaten to penetrate our reality and all of the dreams of the techno-utopiasts play the role in creating this fake virtual world in which human beings driven by desires, devoid of all sense of higher purpose become slaves to algorithms and vast computer intelligences.
What is interesting about this story is the significance it has for Bitcoin. A project which is created for the purpose of creating a decentralized peer-to-peer money that cannot be controlled by governments and central banks but which now finds itself monopolized by large mining cartels. A lack of vision to guide the project forwards and increasing irrelevance in a world facing a global breakup of power.
Lastly I want to explain my project to revitalize the free technology movement to formulate a wider vision to restore back the potential of the technology to transform human society and train the next generation of revolutionary hackers dedicated to the cause of using the technology to support the cause of freedom.
My aim here is to find sponsors, find the place for establishing our hacker Academy, to find partner organisations to develop new technology projects with and to find people ready to dedicate themselves in advancing the free technology movement. People ready to be at the forefront of writing history.

At the heart of this story lies a conflict between two men in 1968. One of them is good B.F. Skinner, the other is good Lewis Mumford. It was one moment when two ideas about how technology could be used to advance human society first XXX ((unintelligible)) to take hold.
There's a documentary from this time made in mid-60s called "Towards tomorrow". And in this documentary, it described two possible future visions for human society. In a society where old forms of authority were declining, what would be the way that we could organize masses of human beings in a future society.
One of these visions for this society was a world managed by an elite group of technocrats, a specialized elite who managed a large population of passive human beings who constantly needed to be monitored and managed to be able to to keep them happy. B.F. Skinner described a new way of controlling and ordering people. He posed the question in this age of mass democracy and individualism the old forms of coercion was simply not possible and he put forth the idea of using reward. And he described an experiment where you have a cage with a pigeon inside and the pigeon can be trained to peck symbols, buttons, and depending on which symbol they peck, they get a pellet of food. In this way, by giving the pigeons the right reward for the correct behavior, they train the pigeon as a mechanical object.
He then took this farther and he went to a mental hospital in San Bernardino in California and in the mental hospital, what they did is they gave the mental patients small reward every time they did a good behavior. With this reward, when it was a lunch time or a dinner time, the patients could sit at a nicer table. So, inside the mental hospital, they created a new ordered hierarchy from a system of reward in which people don't feel controlled but feel empowered. Skinner describes this model as a model for the future of humanity. What's really interesting about this video by Skinner is it there's something very eerily similar to what we see today in which there is a technocratic elite that has interest in politics only in managing human society to keep us happy to keep everything stable and to keep themselves rich. A lot of this was powered in the mid-80s with the fake consumer credit to reward us as a form of social management - much like the experiment with the hospital, the mental hospital.
Lewis Mumford put forward an alternative vision for a society. In this video I'm going to show you - he first criticises Skinner and then he puts forward an alternative vision where everybody in the society is a participant. Everybody is an active human being deciding their destiny.

There were many forms the computer could have taken. In 1800s, the computer was proposed by Babbage. And popularized by Ada Lovelace. It was seen as a tool that would have huge social uses and that should be in the hands of many people, but when the computer was first developed during WWII - for cracking German codes for the military and for guiding ballistic missiles - computers became a very large centralized machine.
By the 80s, communities of hackers started to emerge which started to be fascinated with these huge machines - which at the time you had to get the time slice, to get the appointment to get to get some time to use the machine - they started to get jobs near these computing devices, because they wanted to know how these machines could work. They started to build their own computers in their garages, in their houses and universities - and that was the birth of the personal computers, the reason why we now have laptops and telephones.
What happened was: a lot of big companies started to come along and they started to invest a lot of capital. All of the hacker community - who up until that point had never seen money before in their life - to throw themselves at, at the proprietary industry. And whereas before the culture that had created this personal computers, this liberatory technology, really believed in power to use the technology to improve the humanity for the better, who really believed in free technology, in sharing techniques and code with each other - instead became siloed off.
But there was one guy - Richard Stallman - he was just a guy - he found this ethically wrong. If enough people got together, we could give a challenge against the proprietary industry. He made that as a proposal to the community - that it doesn't have to be this way, if we together put our energies we can build our own operating system. A lot of people at that time thought that he was crazy or that his ideas weren't feasible.
This is early video of Richard Stallman.

So, in 1991, the cryptography was classified as ammunitions and Philip Zimmermann wrote the first freely available encryption software for anybody to use and he uploaded it to the Internet. The American government arrested him and he was facing a decade in prison. What Philip Zimmerman did was to print the source code of PGP - of this encryption software - which he sold internationally, which is something that in America is protected under the First Amendment. And the American government was realizing that they couldn't continue with the case, they dropped the case. And since that time, because of the action of Philip Zimmermann, software became classified as a form of speech. And cryptography became widely available. It's now reason why cryptography is available everywhere.
Also, in early 90s, Stallman has started to piece together his operating system. And by now a community a community of people has emerged around him. It was the birth of Linux - a really important piece of technology. Not just in the free technology world, but in general, in hi-tech space it place a very key role. And that was a rise of the whole bunch of movements: free software movement, hacker movement, crypto-anarchist movement. Movements were invigorated with creating a lot of new ideas and a lot of new concepts about how we could use the technology to shape the world around us. These were collective movements driven by the shared sense of purpose.
Towards the end of the 90s (the baby boomer generation), the western society became overly optimistic. Something the Jean Baudrillard called 'the dead of society' and 'obsession with desert-like forms / with the simulacrum'.
Stallman free software movement failed to capitalize on institutionalizing his movement. And what happen was what emerged was the open source movement. It was a movement that said: making this technology is not a question of freedom/ethics, it's simply when you have access to source code of a program it's more efficient, it's cheaper, it makes more quality code. I don't think that's true, but that was their argument. One of the main spokesmen was Eric Raymond who released a book called 'A cathedral and a bazaar'. In that book, Eric Raymond has described the open source development philosophy as open bazaar where everybody, dozens or hundreds of people, a wide number of people all collaborated in a horizontal manner. He coined an idea that given enough eyes all bugs are shallow. When we have a piece of source code, if there are enough people - all contributing a small amount of time and looking at the source code - then if there is a bug, that bug will be found. The idea that given a huge amount of people with a small amount of contribution of each, that we can develop projects and advance technology.
Then what happened was the biggest event in the modern western history - which was the collapse of the twin towers, the twin idols of capitalism, perfect in a reflections, reaching into the skyline of New York - which realized our deepest most hidden desires to see the destruction of this passive lifeless world. And what it represented was the return of the real (of the) dark forces - that we ignored - back to penetrate into our reality.
In early 2000s we saw a lot of optimism and momentum for change. We saw the Arab spring, we saw The occupy, we saw the orange revolutions. In the technology world, we saw a lot of advances, there was a huge amount of optimism for Linux on the desktop. Every year the people were saying: this is going be the year of the desktop. Everybody was waiting for that sudden single breakthrough. One of the major developments in technology world was the confrontation that took place between Hollywood and a Manhattan programmer called Bram Cohen. ((...)) He developed BitTorrent. The concept started with sites like Napster or Kazaa - that were centralized services that were shut down by authorities.
Cohen came up with a concept: if enough people downloading files and seeding them at the same time - then the more people that download the file the more that file will become widely distributed in the network. So, that file will become shared in a self-regulating network. It was a big success and the movie studios didn't know what to do about this, they were completely powerless in face of this technology. The idea of creating a functional self-regulating system outside of power proved itself and it's something wildly popular among technologists.
The next major development is the shutdown of the Pirate bay which led to the development of the Pirate party that at one point had double digits in elections and even entered into the EU parliament. There is huge momentum behind it. Wikipedia was also developed - the idea that given thousands and thousands of people all contributing small edits, one line at time, could build this huge knowledge resource . Around this movements started to emerge the new priests of this internet-centric decentralization technology - people like Yochai Benkler, academics who would go to conferences and sell this ideology to people.
But something strange started to emerge. Wikipedia released statistics about edits on Wikipedia. We found that it was a small group of dedicated people that wrote the majority of Wikipedia, people who really believed in the project and spent all their time writing the majority of the articles on the website. When we started to look closer at these decentralized systems, what we observed was small groups of leaders surrounded by a wider community. In BitTorent, it wasn't that everybody was seeding in the network. Most people, after they downloaded, didn't continue to run the software. In fact, it was a small group of users, who wanted to challenge Hollywood and promote BitTorrent, who would leave their software running seeding torrents.
In open source, we observed that there were small groups of dedicated developers in a project surrounded by wider community. And in fact, what Stallman has done was not just to write Linux and put that in the community, but he had written articles, he had written manifestos, he had put forward a vision and an ideology that pulled together enough people and drove this movement of hackers forwards.
So what drove these projects for freedom was not a new model or a new technique. It was a vision that pulled together enough people to realize an idea. To understand why Occupy and Arab Spring and orange revolutions and the Pirate Party and a lot of these movements had a huge of amount of will and movement - fail, it's really instructive to understand what happened to Egypt. In Egypt, huge amounts of youths started to mobilize through Facebook and they started to go to this center in Cairo to front the military dictatorship. Huge amount of people died in that struggle. And after they threw out ((?)) the military dictatorship, the youth then sat down and said: "Okay, now what we are gonna do? What's next?". So they started to discuss.
And into that, came a group of people, with a vision, with an ideology, that was well organized and able to pull together enough strands of the society behind them. But they could put their vision into power. And that was the Muslim Brotherhood.
And then the same youth hood - that kicked out the military dictatorship - came back to the square to ask the military dictatorship to come back and rescue them from the Islamists.
At the same time, Satoshi developed Bitcoin. I remember on Satoshi's early website he described it as a peer-to-peer form of money that cannot be controlled by central banks and governments. And it's something that attracted libertarians, cryptographers and hackers. Bitcoin is kind of a technology - free technology project - that was a little late to the party. Interestingly, it finds itself in the same place as the movements that preceded it. The fundamental problem with Bitcoin is not a problem of missing this or that technology, it's a problem of a lack of vision, a lack of how this technology is -
And it's not just about Bitcoin - it's something to do with the wider technology movement. We have to understand the global situation now. Humanity is facing a future with a huge amount of suffering. We are facing the threats from terrorism, from immigration. There's the rise of new ideological movements - ISIS just went and took a city in southern Philippines for more than a month - which is right next to Indonesia, the biggest Muslim country in the world. And in Europe the new right movement is getting very strong, organizing training camps, becoming well-organized, getting into political power and well-funded. This is the reality of our situation now.
We have to think about how this technologies that we make -, where do they situate themselves in the wider global context.
In Rojava, there is also a really important movement with the ideology of democratic confederalism which is the way forward from anarchism. And offers a really good analysis of what is the current society and what is the crisis that we're facing. And how, in that place, revolutionaries from all over the world are going to learning the methodology and ideology of this movement. It's a new emerging movement outside of any one person's control, but new forces can be harnessed. What we have to understand is that anarchist movement and the hacker movement is something deeply connected. The problem with anarchism is that it failed in it's potential to advance humanity forward, it's simply an ideology that no longer is able to work. What we have in Rojava is a libertarian revolution of 5 million people. What is democratic confederalism? It's an ideological movement that opposes the state as a mechanical worldview and sees the nature as something that is divine, that seeks to restore the balance back between internal+subjective and external+material world. The freedom comes from reaching our destiny as human beings, not simply through pleasure seeking. (Liberalism is the destruction of the free society.) And the better humanity it's not simply a happier humanity but stronger freer humanity. The crisis in the West not simply an economic crisis, but social crisis - we're facing a deep cultural issue.
All of the ideas in hacker movement - such as BitLaw, digital governance, cryptographic economy, decentralized organization, new economic models, new technical tools - unless we are able to take all of these concepts and put them into a plan, with a sense of direction, that we can put these into practice - then it's something that's going to be lost. Now, what's presenting itself is a massive opportunity for hackers to put their ideas into practice.
So, right now we are building a hacker team. There's 3 tasks we have to do: study of all the ideas and concepts in technology. From this study we have to develop a long- term plan. And thirdly, we have to devote ourselves to build the technical base of this new emerging democratic confederalism movement, we have to create revolutionary hackers dedicated to the course. If we don't, then all of the technology we are making is outside of the society, it's a toy, and what is relevant in this world is not making new products to fill the spaces in the environment around us, but using technology to shape politics that influence the world around us.
This revolution in North Syria or Rojava is the biggest opportunity in the entire history of modernity. Through this we can give direction to the hacker movement. One of our main projects is a Bitcoin project. We have a nation of 5 million people and - and - and there is a financial situation where they're under financial embargo, they use - , they don't have the financial infrastructure so they use paper money and Syrian Lira is inflating massively. Because there's embargo so you can't send money in and out. Also there is a project to create decentralized economy and there's a lot of real concrete uses for Bitcoin. And also the ideology of the revolutionary nation is in line with the vision and values of the Bitcoin.
When we decide to look at deploying Bitcoin, what we realize is that Bitcoin is not ready and there's a lot of new things that need to be developed in Bitcoin, they should make it so it's able to be deployed on a scale of 5 million people. We are assembling a project to deploy Bitcoin as the national currency of Rojava. We want to create new products in practical use on a large scale. Products that solve real problems and serve the cause of freedom.
Towards this goal, we're assembling a team of 20 hackers dedicated for two years. We're looking to establish links with companies and sponsors to make this happen. The first step is to establish a hacker's academy in Greece - to train groups of revolutionary self-sufficient hackers that we're going to deploy on projects. Our needs now: partners, sponsors, space, support.
Our first plan is to setup exchange shops and localized wallets in Bitcoin where people come buy vouchers and use Bitcoin to create a local Bitcoin market. We have to create brochures, lots of information. Once this system gets bigger, then we also need to think of bigger financial infrastructure - so one of the things is paper wallets. At the moment, 100 thousands paper wallet cost $6000. Unfortunately the counterfeiting measures on the paper wallets aren't very well made. There needs to be a lot research done. There is a small USB device called ESP 12 which can be programmed with micro Python and C and it has on-board Wi-Fi, plus you can fit modules for radio. Through that you can create a large scale payments networks with cheap consumer devices that cost fie dollars each for people to transact bitcoins.
There is also a big market for Bitcoin because sending money between Rojava and Istanbul currently costs 5 %. Later, we also can create plastic card system where we print cards and also establish payments network using radio systems. There needs to be a lot of development and investigations in Lightning Networks and other technologies.
This is why I [want to ((?))] have a laboratory - if I take a group of people there - I can create all kinds of technology projects and a lot of concepts we've been theorizing for a long time. We can see that it works practically.
There is also the project of the Pirates to create liquid democracy - there is a system of local councils in every neighborhood which - , a lot of these digital platforms that have been developed for many years - we can deploy them. There was also the economy being based on cooperatives - all of the ideas about economic management, about collective management of resources about using cryptography and currencies to manage cooperatives. These all things we can deploy - but what it's going to take is a group of people who's doing this research, who's going deep - not only in terms of developing new concepts - but looking back into the literature about what were - , what is the history of the movement, where we situated it and also what are the concepts and how we can apply them towards our goal.
I'm gonna to finish my talk on that. Does anybody have questions?
submitted by vbenes to Bitcoin [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]

Rolling UTXO set hashes | Pieter Wuille | May 15 2017

Pieter Wuille on May 15 2017:
Hello all,
I would like to discuss a way of computing a UTXO set hash that is
very efficient to update, but does not support any compact proofs of
existence or non-existence.
Much has been written on the topic of various data structures and
derived hashes for the UTXO/TXO set before (including Alan Reiner's
trust-free lite nodes [1], Peter Todd's TXO MMR commitments [2] [3],
or Bram Cohen's TXO bitfield [4]). They all provide interesting extra
functionality or tradeoffs, but require invasive changes to the P2P
protocol or how wallets work, or force nodes to maintain their
database in a normative fashion. Instead, here I focus on an efficient
hash that supports nothing but comparing two UTXO sets. However, it is
not incompatible with any of those other approaches, so we can gain
some of the advantages of a UTXO hash without adopting something that
may be incompatible with future protocol enhancements.
  1. Incremental hashing
Computing a hash of the UTXO set is easy when it does not need
efficient updates, and when we can assume a fixed serialization with a
normative ordering for the data in it - just serialize the whole thing
and hash it. As different software or releases may use different
database models for the UTXO set, a solution that is order-independent
would seem preferable.
This brings us to the problem of computing a hash of unordered data.
Several approaches that accomplish this through incremental hashing
were suggested in [5], including XHASH, AdHash, and MuHash. XHASH
consists of first hashing all the set elements independently, and
XORing all those hashes together. This is insecure, as Gaussian
elimination can easily find a subset of random hashes that XOR to a
given value. AdHash/MuHash are similar, except addition/multiplication
modulo a large prime are used instead of XOR. Wagner [6] showed that
attacking XHASH or AdHash is an instance of a generalized birthday
problem (called the k-sum problem in his paper, with unrestricted k),
and gives a O(22*sqrt(n-1)) algorithm to attack it (for n-bit
hashes). As a result, AdHash with 256-bit hashes only has 31 bits of
security.
Thankfully, [6] also shows that the k-sum problem cannot be
efficiently solved in groups in which the discrete logarithm problem
is hard, as an efficient k-sum solver can be used to compute discrete
logarithms. As a result, MuHash modulo a sufficiently large safe prime
is provably secure under the DL assumption. Common guidelines on
security parameters [7] say that 3072-bit DL has about 128 bits of
security. A final 256-bit hash can be applied to the 3072-bit result
without loss of security to reduce the final size.
An alternative to multiplication modulo a prime is using an elliptic
curve group. Due to the ECDLP assumption, which the security of
Bitcoin signatures already relies on, this also results in security
against k-sum solving. This approach is used in the Elliptic Curve
Multiset Hash (ECMH) in [8]. For this to work, we must "hash onto a
curve point" in a way that results in points without known discrete
logarithm. The paper suggests using (controversial) binary elliptic
curves to make that operation efficient. If we only consider
secp256k1, one approach is just reading potential X coordinates from a
PRNG until one is found that has a corresponding Y coordinate
according to the curve equation. On average, 2 iterations are needed.
A constant time algorithm to hash onto the curve exists as well [9],
but it is only slightly faster and is much more complicated to
implement.
AdHash-like constructions with a sufficiently large intermediate hash
can be made secure against Wagner's algorithm, as suggested in [10].
4160-bit hashes would be needed for 128 bits of security. When
repetition is allowed, [8] gives a stronger attack against AdHash,
suggesting that as much as 400000 bits are needed. While repetition is
not directly an issue for our use case, it would be nice if
verification software would not be required to check for duplicated
entries.
  1. Efficient addition and deletion
Interestingly, both ECMH and MuHash not only support adding set
elements in any order but also deleting in any order. As a result, we
can simply maintain a running sum for the UTXO set as a whole, and
add/subtract when creating/spending an output in it. In the case of
MuHash it is slightly more complicated, as computing an inverse is
relatively expensive. This can be solved by representing the running
value as a fraction, and multiplying created elements into the
numerator and spent elements into the denominator. Only when the final
hash is desired, a single modular inverse and multiplication is needed
to combine the two.
As the update operations are also associative, H(a)+H(b)+H(c)+H(d) can
in fact be computed as (H(a)+H(b)) + (H(c)+H(d)). This implies that
all of this is perfectly parallellizable: each thread can process an
arbitrary subset of the update operations, allowing them to be
efficiently combined later.
  1. Comparison of approaches
Numbers below are based on preliminary benchmarks on a single thread
of a i7-6820HQ CPU running at 3.4GHz.
(1) (MuHash) Multiplying 3072-bit hashes mod 23072 - 1103717 (the
largest 3072-bit safe prime).
* Needs a fast modular multiplication/inverse implementation. * Using SHA512 + ChaCha20 for generating the hashes takes 1.2us per element. * Modular multiplication using GMP takes 1.5us per element (2.5us 
with a 60-line C+asm implementation).
* 768 bytes for maintaining a running sum (384 for numerator, 384 
for denominator)
* Very common security assumption. Even if the DL assumption would 
be broken (but no k-sum algorithm faster than Wagner's is found), this
still maintains 110 bits of security.
(2) (ECMH) Adding secp256k1 EC points
* Much more complicated than the previous approaches when 
implementing from scratch, but almost no extra complexity when ECDSA
secp256k1 signature validation is already implemented.
* Using SHA512 + libsecp256k1's point decompression for generating 
the points takes 11us per element on average.
* Addition/subtracting of N points takes 5.25us + 0.25us*N. * 64 bytes for a running sum. * Identical security assumption as Bitcoin's signatures. 
Using the numbers above, we find that:
24ms (2) 100ms
block takes (1) 3ms (2) 0.5ms
Note that while (2) has higher CPU usage than (1) in general, it has
lower latency when using precomputed per-transaction aggregates. Using
such aggregates is also more feasible as they're only 64 bytes rather
than 768. Because of simplicity, (1) has my preference.
Overall, these numbers are sufficiently low (note that they can be
parallellized) that it would be reasonable for full nodes and/or other
software to always maintain one of them, and effectively have a
rolling cryptographical checksum of the UTXO set at all times.
  1. Use cases
computation. This currently requires minutes of I/O and CPU, as it
serializes and hashes the entire UTXO set. A rolling set hash would
make this instant, making the whole RPC much more usable for sanity
checking.
blocks/UTXO sets.
the past few blocks (computed on the fly), a consistency check can be
done that recomputes it based on the database.
[1] https://bitcointalk.org/index.php?topic=88208.0
[2] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-May/012715.html
[3] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-February/013591.html
[4] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-March/013928.html
[5] https://cseweb.ucsd.edu/~mihipapers/inchash.pdf
[6] https://people.eecs.berkeley.edu/~daw/papers/genbday.html
[7] https://www.keylength.com/
[8] https://arxiv.org/pdf/1601.06502.pdf
[9] https://www.di.ens.f~fouque/pub/latincrypt12.pdf
[10] http://csrc.nist.gov/groups/ST/hash/sha-3/Aug2014/documents/gligoroski_paper_sha3_2014_workshop.pdf
Cheers,

Pieter
original: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014337.html
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History of Bitcoin: An analysis of where it's been, where it is, and where it's going.

What is Bitcoin? A brief history.
Okay. So we know that cryptocurrencies are non-state issued currencies that seek to maintain value through scarcity (usually), security (hopefully), and easy transferability regardless of national borders (indubitably).
Bitcoin does all of these things...but so do other cryptocurrencies. Why is Bitcoin special? Let's start with a bit of history.
Beginning in the 1980s, a group of developers and activists formed a list serve and named themselves the Cypherpunks. This group was obsessed with societal privacy and anonymity. They believed that only complete privacy and security could guarantee a free and open society and that the government could not be relied upon to ensure it. Members of the group sought different modes to achieve this goal. Among others:
Bram Cohen: BitTorrent -> Peer to Peer information sharing
Nick Szabo: Bit Gold -> predecessor of Bitcoin, originator of smart contracts
Julian Assange: WikiLeaks -> classified and secret document archive and disclosure
Another person (?) on this list was "Satoshi Nakamoto" who, in his seminal whitepaper in 2009, outlined Bitcoin. Note that "Satoshi Nakamoto" is in quotation marks because his or her or their true identity is thus far unconfirmed. Regardless, Nakamoto's whitepaper conceptualized Bitcoin and in the process created the idea of the blockchain and solved the double spending problem. The double spending problem was something that had plagued digital currencies since they were first proposed. The problem, characterized by a digital currency's lack of physical permanence and resultant ability to be copied, forged, or otherwise falsified, prevent digital currency from progressing past the point of "internet money".
Nakamoto managed to resolve double-spending this via implementation of the blockchain. Let me explain how:
Traditional transactions are pretty straightforward. Party A gives Party B some number of dollars. Party B accepts this money without concern because, the possibility of counterfeiting not withstanding, he is pretty sure that the dollars that he is receiving are legitimate. Since dollars are physical, they can only be spent in one place at a time.
Image 1
This works great when both parties are confident that the money being transacted can only be spent once as is the case with physical money. Digital money is intangible by its nature and therefore, double spending is a concern.
Say that Party A has BitCash A. He wants to purchase goods from Party B and Party C. The goods to be purchased EACH cost BitCash A. If Party A is honest, he will only purchase one of the goods since he can't afford both. Party A is a bad dude, though, and decides to try to pull a fast one on Party B and Party C. Since BitCash is just internet money, it's easily reproducible and requires only a quick copy and paste to dupe the system. Party A sends BitCash A to Party B as well as to Party C. Someone is loses money (likely the whole network since this is a fatal flaw in the currency and indicates underlying unreliability).
Image 2
For those of you wondering how credit cards and other digital systems alleviate this issue, they do it through a centralized ledger. In other words, a third party is needed to mediate transactions and to ensure that money only exists in one place at a time. While this works in the context of traditional banking, this system goes against the ethos of Bitcoin, which is predicated on decentralization, privacy, and anonymity. Additionally, the idea of trusting a third party to verify all transactions introduced a single point of potential failure, something that cryptocurrencies sought to avoid.
The above issue remained unsolved until Nakamoto's invention of Bitcoin. Nakamoto introduced the idea of the blockchain, a constantly updated decentralized universal ledger that existed everywhere and nowhere, that was maintained by multiple parties on the network, and that was permanently reliable. Each transaction had to be verified by multiple parties (known as miners) as being legitimate before becoming irreversibly codified in the universal ledger known as the blockchain. Should a party seek to double spend, one of the transactions put forth would be rejected: either the one that was placed second, or the one that received fewer confirmations from the network. By relying on a second party system, the double spending problem was solved.
Image 3
In the above case, Party A attempts to double spend his Bitcoin A to Party B and Party C. Both proposed transactions are sent to miners to verify. Only one of the two is accepted by the network and added to the blockchain. In this case, the Bitcoin A sent to Party B is confirmed as legitimate while the proposed transaction to Party C is rejected. Bitcoin A is NOT double spent. Party B ends up with Bitcoin A and Party C ends up with nothing.
With the double spending problem and others worked out, Bitcoin became a viable mode for transaction. The first official Bitcoin transaction occurred on January 12, 2009 between Nakamoto and Hal Finney. Bitcoin ceased to be theoretical and entered the real world. Exchanges began carrying Bitcoin and facilitating its transfer between people. Over the next several years Bitcoin's value grew from fractions of a cent to over $11000 (as of 12/3/17).
Image 4
Image 5
Image 6
In addition to its own growth, Bitcoin is also responsible for the rise of cryptocurrencies in general as the majority of cryptocurrencies today have used Bitcoin as their foundational model.
Image 7
Controversies
Bitcoin's ascent has been marred by several controversies both internal and external.
Advantages of Bitcoin over other cryptocurrencies
I've broken down the major advantages of Bitcoin as follows:
Image 8
Ubiquity/cachet: Ultimately, much of the advantage that Bitcoin possesses boils down to its place as the cryptocurrency leader. Odds are that when people say "cryptocurrency", they really mean Bitcoin. There's value to being at the top of the market and its position affords it a host of benefits. It has the largest user base of any of the cryptocurrencies which fuels its dollar value. Because it was first to market, and because of its users, it also has a robust development community working both internally and externally. One of the perks of investing in Bitcoin is the exposure that one gets to Bitcoin forks. Bitcoin Cash, a fork that occurred on August 1, 2017, is currently trading over $1600/coin. Every user of Bitcoin received Bitcoin Cash...just for holding Bitcoin. There have been other forks since, and there will continue to be forks in the future, all adding potential value to a Bitcoin investment. Furthermore, Bitcoin is relatively established and more robust to insults than other cryptocurrencies, making it a safer store of value.
In order to be unseated as the clear crypto king, a new product would need to show up that is not only qualitatively better than Bitcoin, but better enough that it makes ditching the Bitcoin environment worth it.
Technology: Bitcoin was the first cryptocurrency to reliably show that digital money could be used for transactions and as stores of value. As mentioned above, most cryptocurrencies today use the Bitcoin white paper as their model. We know that the foundations of Bitcoin are comparatively sound and that it is stable. This stability has allowed a healthy ecosystem of development to take root. Interested in buying a hardware wallet for your Bitcoin? They exist. More interested in creating a free online wallet? Those exist. Interested in mining? It's easy, albeit expensive to get started. The technology being proven has allowed the adjacent technologies to thrive.
Price: While most would consider an $11000 entry tag to be a massive barrier to entry and potentially stifling, it's actually a major boon to Bitcoin. The price tag attracts investors and users, which encourages development, which makes the product more functional, which attracts users, which increases price, etc. Bitcoin is worth something and makes it difficult to dismiss. Furthermore, its high price tempers volatility and manipulation. Unlike other currencies that are worth pennies or dollars, Bitcoin is able to weather large capital inflows and outflows and is less prone to overt market manipulation precisely because its market cap is so high.
Risks
Image 9
Internal
Technology: While Bitcoin functions completely adequately today, it will need to scale tremendously to reach its potential. While the technology behind Bitcoin is impressive, it pales in comparison to established modes of exchange. VISA averages 2000 transactions per second and has a peak capacity of 56000 transactions per second. Bitcoin presently averages 7 transactions per second. Certain solutions are being explored, like the Lightning Network, but there are no guarantees that there will be successful implementation.
As can be said with any technology, Bitcoin is fundamentally dependent on its underlying code. Thus far it has had only one major exposed flaw (which resulted in the accidental creation of 184 billion Bitcoin).
Development: Mentioned above was the advantage conveyed by forks. They can provide additional value. This is a good thing. They can also create competitors. This is a bad thing. While it is unlikely that a Bitcoin offshoot will unseat Bitcoin outright, there is the risk of market cannibalization and confusion with each new iteration. Which is the real Bitcoin?
External
Legislative: Because Bitcoin can so ably provide for functions that were once strictly in the government domain, it is likely to become the target of governmental limits at some point. We've already seen China try to crack down on Bitcoin and it's reasonable to assume that other countries will follow suit.
Despite this risk, however, Bitcoin has proven to be incredibly resilient and is still traded by the Chinese. Since the Chinese ban, Bitcoin's price has nearly doubled from $6000 to over $11000 today (12/3/17).
Competitive: I mentioned earlier that one of Bitcoin's main advantages was that it was first to market. While this is a tremendous benefit today, it does not guarantee ongoing success. History is littered with famous "firsts to market" that were overtaken by savvy competitors. The World was the first ISP to market. Magnavox released the first video game console. You'd be hard pressed to find someone that equates ISPs with The World or video game consoles with Magnavox.
Bitcoin is not on the precipice of being overtaken by another cryptocurrency. However, the risk of an existing competitor, or more likely a new competitor that doesn't yet exist, supplanting Bitcoin is always a possibility and investors should mitigate risk appropriately.
Investment opportunities: Bitcoin provides the surest cryptocurrency investment for the reasons mentioned above. Its status as the cryptocurrency leader makes it the most stable investment in the arena. Furthermore, its cachet makes it an attractive investment to lay investors looking for exposure to this particular market which subsequently makes it an even more attractive investment. While many may balk at investing in something whose single unit is priced at more than $11000 and that has experienced explosive growth, I believe that Bitcoin still has opportunity for upward movement.
The number I keep coming back to is $7.8T (trillion). That's the market cap for gold. I use this as a bench mark because I see Bitcoin supplanting gold as a storage of wealth from fiat currencies. As I've discussed, the blockchain provides permanence in a way that is akin to gold's physical permanence.
The present market cap for ALL cryptocurrencies is $340B (billion). Bitcoin presently accounts for 55% of the cryptocurrency market cap with $188B.
Assuming that over the next year growth slows over the next year and that Bitcoin loses some of its dominance, I still think that it's reasonable to project an approximate Bitcoin value of $50000. This assumes that the crypto market continues to grow, albeit at a slower relative pace and still does not approach gold's market cap.
Image 10
This is bullish and I assume that no major stumbling blocks present themselves. I am drawn to the fact that market penetration is still relatively low and that institutional money has barely begun to enter the market. These two factors mean that organic growth can continue for the foreseeable future.
Conclusion
Bitcoin represents the present pinnacle of the cryptocurrency market. As an investment, it provides the best combination of stability and potential growth precisely because it is the market leader. Through its innovation of the blockchain, it has spurred the cryptocurrency explosion that we have witnessed over the last several years.
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In light of the recent low cost of block space, an alternative to fee estimation algorithms

This is the best tl;dr I could make, original reduced by 90%. (I'm a bot)
Since transaction fees are a good thing, that brings up the question: How should wallets handle them? This essay is an expansion of my talk at the bitcoin scaling conference.
What should transaction fees be?Before figuring out how wallets should calculate transaction fees, we first need to know what transaction fees should be.
At a minimum it's necessary to have a maximum fee which the user is willing to spend in order to make a transaction go through, which of course means that some transactions will fail because they aren't willing to pay enough, which is the whole point of having transaction fees in the first place.
Unfortunately right now the only way to make sure that a transaction is permanently failed is to spend its input on something else, but that requires spending a transaction fee on the canceling transaction, which of course would be just as big as the fee you weren't willing to spend to make the real transaction go through in the first place.
What information to useThe most obvious piece of information to use for setting transaction fees is past transaction fees from the last few blocks.
If transaction fees are sticky, a large but still minority miner can make money for themselves even in the short term by artificially pumping fees in one of their blocks because fees will probably still be high by the time of their next block.
Summary Source | FAQ | Feedback | Top keywords: transaction#1 fee#2 block#3 time#4 more#5
Post found in /Bitcoin, /Bitcoin, /Buttcoin, /btc and /BitcoinAll.
NOTICE: This thread is for discussing the submission topic. Please do not discuss the concept of the autotldr bot here.
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The TXO bitfield | Bram Cohen | Mar 31 2017

Bram Cohen on Mar 31 2017:
Looking forward in node scaling we can envision a future in which blocks
are required to come with proofs of their validity and nodes can be run
entirely in memory and never have to hit disk. Ideally we'd like for proofs
to be able to be stored in client wallets which plan to spend their utxos
later, or at least be able to have a full node make a single not terribly
expensive disk access to form the proof which can then be passed along to
other peers.
Such proofs will probably be significantly larger than the blocks they
prove (this is merkle root stuff, not zero knowledge stuff), but if we
accept that as a given then this should be doable, although the details of
how to do it aren't obvious.
This vision can be implemented simply and efficiently by playing some games
with the semantics of the term 'proof'. A proof is a thing which convinces
someone of something. What we've discussed in the past for such proofs
mostly has to do with maintaining a hash root of everything and having
proofs lead to that. This is an extrema of complexity of the proof and
simplicity of the checker, at the expense of forcing the root to be
maintained at all times and the proof to be reasonably fresh. Some tricks
can be applied to keep that problem under control, but there's an
alternative approach where the amount of data necessary to do validation is
much larger but still entirely reasonable to keep in memory, and the sizes
of proofs and their required freshness is much smaller.
In the previous discussion on Merkle sets I commented that insertion
ordering's main practical utility may be that it allows for compression. It
turns out that a constant factor of 256 makes a big difference. Since
there's only really one bit stored for each txo (stored or not) once you
have an insertion ordering you can simply store a bitfield of all txos so
far, which is entirely reasonable to hold in memory, and can be made even
more reasonable by compactifying down the older, mostly spent portions of
it (how best to compress a bitfield while maintaining random access is an
interesting problem but entirely doable).
This approach meets all the design goals, even allowing wallets to remember
their own 'proofs', which are just proofs of insertion ordering. Those
don't even change once the risk of reorgs has passed, so they can be stored
for years without being maintained.
Proofs of insertion ordering can be made by having a canonical way of
calculating a root of position commitments for each block, and nodes
calculate those roots when evaluating the block history and store them all
in memory. A proof of position is a path to one of those roots.
I've intentionally skipped over most of the details here, because it's
probably best to have a high level discussion of this as a general approach
before getting lost in the weeds.
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How wallets can handle real transaction fees | Bram Cohen | Nov 07 2015

Bram Cohen on Nov 07 2015:
(My apologies for a 'drive-by' posting. I'm not subscribed to this mailing
list but this post may be of interest here. If you'd like to make sure I
see a response send it to me directly. This post was originally posted to
the web at
https://medium.com/@bramcohen/how-wallets-can-handle-transaction-fees-ff5d020d14fb
)
Since transaction fees are a good thing (see
https://medium.com/@bramcohen/bitcoin-s-ironic-crisis-32226a85e39f ), that
brings up the question: How should wallets handle them? This essay is an
expansion of my talk at the bitcoin scaling conference (see
https://www.youtube.com/watch?v=iKDC2DpzNbw&t=13m17s and
https://scalingbitcoin.org/montreal2015/presentations/Day1/11-bram_wallet_fees.pdf
).
Ground Rules
To answer this question we first need to lay down some ground rules of what
we’re trying to solve. We’ll focus on trying to solve the problem for
consumer wallets only. We’ll be ignoring microchannels, which dramatically
reduce the number of transactions used but still have to put some on the
blockchain. We’ll also be assuming that full replace by fee is in effect
(see
https://medium.com/@bramcohen/the-inevitable-demise-of-unconfirmed-bitcoin-transactions-8b5f66a44a35
)
because the best solution uses that fairly aggressively.
What should transaction fees be?
Before figuring out how wallets should calculate transaction fees, we first
need to know what transaction fees should be. The obvious solution to that
question is straightforward: It should be determined by supply and demand.
The price is set at the point where the supply and demand curves meet. But
supply and demand curves, while mostly accurate, are a little too simple of
a model to use, because they don’t take into account time. In the real
world, the supply of space for transactions is extremely noisy, because
more becomes available (and has to be immediately consumed or it’s lost
forever) every time a block is minted, and block minting is an
intentionally random process, that randomness being essential for
consensus. Demand is random and cyclical. Random because each transaction
is generated individually so the total amount is noisy (although that
averages out to be somewhat smooth at scale) and has both daily and weekly
cycles, with more transactions done during the day than at night.
What all these result in is that there should be a reward for patience. If
you want or need to get your transaction in quicker you should have to pay
on average a higher fee, and if you’re willing to wait longer it should on
average cost less. Inevitably this will result in transactions taking on
average longer than one block to go through, but it doesn’t require it of
everyone. Those who wish to offer high fees to be sure of getting into the
very next block are free to do so, but if everyone were to do that the
system would fall apart.
What should the wallet user interface be?
Ideally transaction fees would be handled in a way which didn’t require
changes to a wallet’s user interface at all. Unfortunately that isn’t
possible. At a minimum it’s necessary to have a maximum fee which the user
is willing to spend in order to make a transaction go through, which of
course means that some transactions will fail because they aren’t willing
to pay enough, which is the whole point of having transaction fees in the
first place.
Because transaction fees should be lower for people willing to wait longer,
there should be some kind of patience parameter as well. The simplest form
of this is an amount of time which the wallet will spend trying to make the
transaction go through before giving up (Technically it may make sense to
specify block height instead of wall clock time, but that’s close enough to
not change anything meaningful). This results in fairly understandable
concepts of a transaction being ‘pending’ and ‘failed’ which happen at
predictable times.
Transactions eventually getting into a ‘failed’ state instead of going into
permanent limbo is an important part of the wallet fee user experience.
Unfortunately right now the only way to make sure that a transaction is
permanently failed is to spend its input on something else, but that
requires spending a transaction fee on the canceling transaction, which of
course would be just as big as the fee you weren’t willing to spend to make
the real transaction go through in the first place.
What’s needed is a protocol extension so a transaction can make it
impossible for it to be committed once a certain block height has been
reached. The current lack of such an extension is somewhat intentional
because there are significant potential problems with transactions going
bad because a block reorganization happened and some previously accepted
transactions can’t ever be recommitted because their max block height got
surpassed. To combat this, when a transaction with a max block height gets
committed near its cutoff it’s necessary to wait a longer than usual number
of blocks to be sure that it’s safe (I’m intentionally not giving specific
numbers here, some developers have suggested extremely conservative
values). This waiting is annoying but should only apply in the edge case of
failed transactions and is straightforward to implement. The really big
problem is that given the way Bitcoin works today it’s very hard to add
this sort of extension. If any backwards-incompatible change to Bitcoin is
done, it would be a very good idea to use that opportunity to improve
Bitcoin’s extension mechanisms in general and this one in particular.
What information to use
The most obvious piece of information to use for setting transaction fees
is past transaction fees from the last few blocks. This has a number of
problems. If the fee rate goes high, it can get stuck there and take a
while to come down, if ever, even though the equilibrium price should be
lower. A telltale sign of this is high fee blocks which aren’t full, but
it’s trivial for miners to get around that by padding their blocks with
self-paying transactions. To some extent this sort of monopoly pricing is
inherent, but normally it would require a cabal of most miners to pull it
off, because any one miner can make more money in the short term by
accepting every transaction they can instead of restricting the supply of
available transaction space. If transaction fees are sticky, a large but
still minority miner can make money for themselves even in the short term
by artificially pumping fees in one of their blocks because fees will
probably still be high by the time of their next block.
Past fees also create problems for SPV clients, who have to trust the full
nodes they connect to to report past fees accurately. That could be
mitigated by making an extension to the block format to, for example,
report what the minimum fee per bytes paid in this block is in the headers.
It isn’t clear exactly what that extension should do though. Maybe you want
to know the minimum, or the median, or the 25th percentile, or all of the
above. It’s also possible for miners to game the system by making a bunch
of full nodes which only report blocks which are a few back when fees have
recently dropped. There are already some incentives to do that sort of bad
behavior, and it can be mitigated by having SPV clients connect to more
full nodes than they currently do and always go with the max work, but SPV
clients don’t currently do that properly, and it’s unfortunate to create
more incentives for bad behavior.
Another potential source of information for transaction fees is currently
pending transactions in the network. This has a whole lot of problems. It’s
extremely noisy, much more so than regular transaction fees, because (a)
sometimes a backlog of transactions builds up if no blocks happen to have
happened in a while (b) sometimes there aren’t many transactions if a bunch
of blocks went through quickly, and (c) in the future full nodes can and
should have a policy of only forwarding transactions which are likely to
get accepted sometime soon given the other transactions in their pools.
Mempool is also trivially gameable, in exactly the same way as the last few
blocks are gameable, but worse: A miner who wishes to increase fees can run
a whole lot of full nodes and report much higher fees than are really
happening. Unlike with fee reporting in blocks, there’s no way for SPV
clients to audit this properly, even with a protocol extension, and it’s
possible for full nodes to lie in a much more precise and targetted manner.
Creating such a strong incentive for such a trivial and potentially
lucrative attack seems like a very bad idea.
A wallet’s best information to use when setting price are the things which
can be absolutely verified locally: The amount it’s hand to pay in the
past, the current time, how much it’s willing to pay by when. All of these
have unambiguous meanings, precise mathematical values, and no way for
anybody else to game them. A wallet can start at a minimum value, and every
time a new block is minted which doesn’t accept its transaction increase
its fee a little, until finally reaching its maximum value at the very end.
Full nodes can then follow the behavior of storing and forwarding along
several blocks’s worth of transactions, ten times sounds reasonable,
ignoring transactions which pay less per byte than the ones they have
stored, and further requiring that a new block be minted between times when
a single transaction gets replaced by fee. That policy both has the
property of being extremely denial-of-service resistant and minimizing the
damag...[message truncated here by reddit bot]...
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Reporte Semanal #3 Junio 2015 I Análisis de Mercado de Bitex.la

Durante la última semana la moneda digital operó lateral desde una corrección luego del máximo de USD 257.39. Alcanzando el mínimo semanal en USD 238.20 el 24/06. Vemos un soporte firme en USD 240. Podríamos observer una subida hacia la resistencia representada por el círculo azul. Como vemos, no hubo una tendencia clara en terminos de volumen, lo que acompaña la lateralización del precio.
https://d262ilb51hltx0.cloudfront.net/max/1037/1*LaaGVgnyi2fpzEOtHQbKCA.png
Hoy 26/06/2015 (a las 12 hs UTC) el Bitcoin opera en USD 241.20.
Un informe largamente anticipado publicado por el Comité Permanente del Senado Canadiense sobre la Banca y el Comercio ha pedido un “ligero toque normativo” a los bitcoin y monedas digitales.
El informe, titulado “”Digital Currency: You Can’t Flip This Coin!”, se produce después de una revisión que duro meses y que incluyó una serie de audiencias ante la comisión del Senado, sin duda desempeñara un papel importante en cómo el gobierno Canadiense dara forma a una futura regulación .
El comité recomendó al gobierno que busque maneras de utilizar las monedas digitales y la tecnología blockchain, considerando que la tecnología es “ingeniosa” y capaz de satisfacer las necesidades potencialmente críticas, tanto en el sector financiero como en el acceso a servicios bancarios en el mundo.
El informe afirma:
“El gobierno federal [debería], poner en consideración cualquier legislación, regulación y políticas, para crear un entorno que fomente la innovación en las monedas digitales y sus tecnologías asociadas. Como tal, el gobierno debe regular con un “toque ligero” que minimice las acciones que podrían sofocar el desarrollo de estas nuevas tecnologías “.
El comité también recomendó que el trabajo del gobierno con otros países en los marcos regulatorios que ofrecen un enfoque equilibrado para la supervisión y proporcionan información al público sobre las implicaciones legales y fiscales de las monedas digitales, y llevar a cabo nuevos exámenes sobre resultados del estudio en los próximos tres años.
Cabe destacar que el comité recomendó que los cambios de divisa digitales canadienses estén sujetos a regulaciones de transmisión de dinero, sino que las empresas que únicamente ofrecen servicios de monedero en Canadá no deben caer bajo esa clasificación.
El informe citó el lavado de dinero, financiamiento del terrorismo y volatilidad de los precios como “graves obstáculos” para el gobierno como se considera la regulación moneda digital.
El Comité del Senado completo Canadiense Permanente de Banca, Comercio y Comercio informe se puede encontrar a continuación:
https://www.scribd.com/doc/269079778/Digital-Currency-You-Can-t-Flip-This-Coin
Barclays ha comenzado una prueba de concepto a la tecnología bitcoin.
Tras un acuerdo con el Trader de bitcoin Safello, el banco del Reino Unido dice que explorara cómo las tecnologías blockchain podrían reforzar el sector de servicios financieros.
En declaraciones a CoinDesk, el CEO de Safello Frank Schuil dijo que la decisión de Barclays refleja un cambio más amplio en la financiación tradicional:
“Si un Banco Tier I firma una prueba de concepto con una empresa bitcoin no es un indicativo de tiempos en los que estamos, entonces no sé lo que es … su actitud está cambiando y está cambiando rápidamente.”
El anuncio, realizado en la sesión de demostración Barclays Accelerator en Londres, se presenta como el número creciente de bancos que están probando libros mayores distribuidos como el de Ripple.
Safello fue una de las 10 nuevas empresas FinTech que participan en el programa de aceleración de 13 semanas de Barclays, que comenzó el año pasado. Ubicado en el Mile End de Londres, las empresas del régimen reciben una tutoría y herramientas de Barclays, junto con £ 20,000 en financiación inicial del socio TechStars.
Schuil describió el programa como una “experiencia de aprendizaje mutuo” para Barclays y Safello. Aunque los detalles exactos de la pareja de la prueba de concepto se mantienen en secreto,el indicó que la plataforma de gasto bitcoin de Safello podría llegar a un sector demográfico importante para el banco.
“El grupo que tenemos como objetivo es el del milenio que los bancos encuentran difícil de alcanzar, y lo estamos haciendo con una tecnología que tienen que entender”, dijo, y agregó: “De esta manera y de otras maneras que estamos construyendo un puente entre lo tradicional del mundo financiero y el bitcoin “.
Otras seis nuevas empresas en el evento, incluyendo la blockchain-diamond-tracker Everledger, rporto estar en “la exploración de oportunidades” con Barclays.
Una ‘prueba de esfuerzo máximo “planeada para la red Bitcoin fue llevada a cabo sin mayores incidentes, aunque la empresa organizadora del evento, dijo que sólo fue capaz de enviar el 15% del volumen de transacciones que se había previsto.
La Bitcoin broker CoinWallet.eu había planeado la prueba de esfuerzo a partir del 22 de junio a las 13:00 GMT, para durar 100 bloques. Se ha tratado de pasar 20 BTC (alrededor de 5.000 dólares) a las transacciones por un total de aproximadamente 200 MB de datos.
La intención original era inundar la red Bitcoin con transacciones para ver si el tamaño del bloque de 1MB actual era adecuado para tal volumen, y si la red podría recuperarse rápidamente de una oleada.
El objetivo declarado de CoinWallet era demostrar que el tamaño del bloque de 1 MB es insuficiente si el bitcoin llega a ser “algo más que un proyecto de ciencia costosa”.
Diez servidores Bitcoin enviarían dos transacciones por segundo, cada una de aproximadamente 3 KB de tamaño y cada envío de 10 a 20 direcciones. Las salidas de las transacciones (por un total de transacciones más grandes de 15–30KB) serían entonces combinadas y se envíarian de nuevo a los servidores originales.
Esto siguió a una serie de pruebas más cortas de CoinWallet realizadas en los últimos días.
Cuestiones de prueba
Sin embargo, los servidores de CoinWallet fallaron y la prueba no se pudo completar en los volúmenes previstos.
La compañía registró en Reddit:
“A las 17:00 GMT nuestros servidores BitcoinD fallaron. Los servidores fueron renovados, pero no cumplieron con nuestro volumen de transacción prevista. El máximo de espera de la cartera era de 15 MB. Lejos de la meta de 200 MB. A finales de la tarde la prueba se considero completa. Aproximadamente el 15% del volumen previsto ocurrio”.
CoinWallet dijo que lanzará otra prueba en siete días.
Reacciones
CoinWallet había enfrentado críticas por el lanzamiento de la prueba en vivo en una red bitcoin desprevenida, con algunos llamándolo un “ataque”.
Otros, sin embargo, como el desarrollador bitcoin Peter Todd, tenían curiosidad por ver sus efectos y publicaron instrucciones sobre cómo los usuarios podrían asegurar que sus transacciones fueran enviadas de igual manera.
Para la mayoría, el período de prueba parece haber pasado sin incidentes.
Hubo algunos informes anecdóticos de los retrasos de transacción publicados en línea, a pesar de que no ha sido comprobada de que eran el resultado de la prueba u otras circunstancias.
Tasas de transacción más altas
CoinWallet adjunta una gama de diferentes tarifas a sus transacciones de prueba para ver si todos los días más transacciones de Bitcoin se retrasarían. Algunos de los honorarios de prueba superaron los 10.000 Satoshi (0.0001 BTC) por KB de datos de transacción.
El fabricante de software Monedero Multibit publicó en su página web que las transacciones con sólo 1.000 Satoshi (0,00001 BTC) por KB se retrasaron durante la prueba, algunos de ellos toman hasta 87 bloques para confirmar.
La cartera Multibit HD tiene una configuración predeterminada de 3000 Satoshi (0,00003 BTC) por KB, que es ajustable por el usuario entre 1.000 y 10.000 Satoshi.
Las transacciones con valores establecidos de 3000 Satoshi tomaron de 11 a 80 bloques para confirmar, y los establecidos en los máximos de 10.000 Satoshi tomaron un promedio de nueve.
El equipo concluyó:
“Cuando la red Bitcoin se inunda con las transacciones a un nivel de tarifa especial, las operaciones con tasas inferiores no quedan confirmadas en el momento oportuno.”
Mientras que la mayoría en el mundo bitcoin ha discutido recientemente que el bloque de transacción de 10 minutos deberia de ser aumentado a 8 MB o 20 MB para manejar volúmenes más grandes, otros prefieren el status quo.
El creador del Protocolo BitTorrent, Bram Cohen escribió en un blog titulado “La ironica crisis Bitcoin” que tamaños de bloque de 1MB son preferibles, ya que esto daría lugar a una mayor competencia en las tasas de transacción y, a su vez beneficiará a los mineros que mantienen la red segura.
El proveedor de servicios de pago en linea Vogogo ha recaudado $ 12,5 millones como parte de un acuerdo de financiación en una ronda dirigida por inversionistas como Beacon Securities, Clarus Securities y Salmon Parteners.
La financiación trae una recaudación de fondos total de $ 21 millones. Vogogo recaudó $ 8,5 millones en fondos de riesgo en agosto del año pasado, antes de su debut en la Bolsa de Valores de Toronto en septiembre.
Como parte de la financiación ,Beacon, Clarus y salmón actuaron como los vendedores oficiales de acciones de Vogogo en el mercado libre a cambio de una tasa sobre los ingresos totales.
El CEO de Vogogo Geoff Gordon indicó que los fondos serán utilizados por la empresa para adquisiciones clave, depósitos de seguridad con los socios de la banca y en el fomento de la ventaja del primer movimiento como una firma de cumplimiento centrada en el espacio de las criptomonedas.
Gordon dijo a CoinDesk:
“Creo que hay grupos que son capaces de hacerlo, pero estamos claramente por delante de cualquier competidor potencial. Apuntamos al largo plazo y queremos activar esta industria con una buena gestión de riesgos y cumplimiento.”
Gordon sugirió que los fondos ayudarán a “sentar cabeza” las acciones de la compañía, que han disminuido de un máximo de tres meses de $ 3.50 por acción el 10 de abril a un total de $ 1.93.
Vogogo ha estimado que ahora tiene 20 clientes de la industria de las criptomonedas integrandos con sus productos,el de más alto perfil es el intercambio Bitstamp. Sin embargo, Gordon indicó que este grupo de clientes se está diversificando ya que la industria evoluciona.
“Estamos yendo con la plataforma, pero nosotros seguiremos viendo nuevos grupos que vienen a nosotros. Ustedes todavía tienen grandes intercambios, pero es ahora servicios de remesas y diversos servicios financieros”, dijo.
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Cyber Initiative - YouTube Blockchain at Berkeley - YouTube Neutrino: The Privacy Preserving Bitcoin Light Client Blockchain pruning How to limit the blockchain size securely Facebook Coin: guerra al dollaro! ( Tg Crypto 2019 06 18 )

Bram Cohen's Chia is a cryptocurrency based on proof-of-space rather than proof-of-work, a green alternative to bitcoin that its creator hopes will displace its energy hungry predecessor. Bram Cohen Jul 2, 2015 · 5 min read In Bitcoin there’s a practice roughly equivalent to accepting a check which hasn’t been committed by the block chain yet, known as accepting unconfirmed ... Bram Cohen released Bittorrent to the world in 2004, but, in early 2017, he stepped away from the company he built to focus on blockchain technology. A very technical paper was co-authored by Cohen and released in September 2017 titled “Beyond Hellman’s Time-Memory Trade-Offs with Applications to Proofs of Space,” that covered “Proofs of Space” as a blockchain consensus method. Bram Cohen, BitTorrent’s inventor, was reported to have officially stepped away from the company in mid-August and has continued to pursue his own cryptocurrency project named Chia. However, it appears as though Tron is still interested in Cohen’s works. This essay is an expansion of my talk at the bitcoin scaling conference. To answer this question… Open in app. Become a member. Sign in. How wallets can handle transaction fees. Bram Cohen ...

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Bram Cohen, creator of BitTorrent, talks about Proof of Space and Time, the consensus algorithm for his new Chia Network blockchain. Bitcoin: 1LeM... Skip navigation Sign in. Search. Loading... Close. This video is unavailable. ... Bram Cohen: ... Transaction confirmations on the blockchain and in your wallet - Duration: 2:44 ... What is a Bitcoin Wallet? (in Plain English) - Duration: 13 ... Proof of Space & Time w/ Bram Cohen - Duration: 1:03:29. Taariq Lewis 677 ... Tracking Bitcoin Transactions on the Blockchain - SANS ... #blockchain #criptovalute #cryptocurrency #TgCrypto ----- 2:43 Facebook Unveils Wallet For Pseudo-Cryptocurrency ‘Libra’ 5:55 Cameron Winklevoss: “tutte le FAANG avranno una coin” - 7:02 ... Olaoluwa Osuntokun (roasbeef), Cofounder at Lightning Labs, spoke about Neutrino, a privacy preserving Bitcoin light client. Slides can be found here: https:...

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