Sorry for misreading your questions. The article talks about blockchains in general, it does not refer to one in particular, so it is not possible to give specific answers to your questions.
When people talk about "general purpose" blockchains, usually they have in mind Ethereum (which uses cpu-resistant POW, to make sure ASICs are not economical. Planning to transition to POS) and Hyperledger which uses PBFT. My understanding of Hyperledger is that is assumes that most nodes are acting in good faith, but I might be wrong.
It's a VM, but it's not free. You need to pay the cost of CPU processing, so to be able to be 'unkillable', a virus will need to be able to generate revenues on its own, to be able to support its "life-style".
But yeah, being turing-complete is a major challenge. Ethereum sustained a major DOS attack a few months ago because some opcodes were mispriced. An attacker was able to bog down the network with a relatively small investment.
Yup that's the biggest hurdle right now but multiple ideas are being explored. The one that I personally find the most promising is "sharding", an idea developed to allow the Ethereum blockchain to scale massively. In a nutshell, they will split the blockchain in multiple shards and allow transactions between them.
Woah that's a lot of questions. Let me try to answer the first two:
What is the "proof of work" used by the blockchain to decide which node gets to commit to the permanent blockchain record? A complex mathematical question that takes a long time to answer. Complexity of the question is adjusted dynamically to aim for a regular block "commit" like you say. There are alternatives to PoW, like Proof Of Stake (PoS) where you "stake" an amount of money that you will lose if you cheat.
How will the blockchain handle if a pool of nodes consisting of > 50% of the computing power for proof of work decides to "double spend" or alter a blockchain record? It happened on smaller, less popular blockchains, where the investment to hire the necessary computer power was relatively small. That's why bigger, more popular blockchains are considered more "secure". For bitcoin, that would cost hundreds of millions and you might gain at most thousands of dollars. Double-spending will be discovered a few blocks later, that don't leave you a lot of time to cash out the bitcoins.
Actually, it is quite the opposite. Blockchain platforms, like Ethereum, are being built to address the re-centralization problems that you describe.
Ethereum aims to build a centralized "world-computer" with 3 main components: - ethereum blockchain: decentralized turing-complete VM, with built-in ability to create cryptocurrencies - swarm: decentralized storage, similar to IPFS - whisper: decentralized messaging
The project is still in its infancy, but it's already usable. Still not 100% decentralized as it still relies on HTTP and DNS, and scaling is on the roadmap. Just to give you an idea of what this platforms makes possible, here are examples of projects already launched or in alpha: - OasisDEX: A decentralized cryptoasset exchange - ENS: Decentralized Naming Service, to replace DNS - uPort: self-sovereign identity - Everex: remittance for migrant workers
They don't have to inspect de packet content to determine what's the kind of traffic. They could use the stats that the routers gather.
I don't know how they did it, but here's how I would proceed:
You need is an access to the NetFlow data of a couple of Cisco routers on the ISP network. This data contains statistics about the connections between two IP adress like the port numbers, packets/bytes numbers and timestamps.
Then you setup a server to poll regularly the routers, aggregate the data and generate nice graphs using a software like FlowScan: http://www.caida.org/tools/utilities/fl owscan/
Nothing complicated, the difficult part is to explain to the ISP why they should enable NetFlow and give you access. (It adds a little load on the router).
Anonymous poster is totally right. Internet2 runs on IPv4, but there is experimental IPv6 tunnels. They may have a couple experimental dedicated link these days, but that's all.
Lightpaths is an exciting development in networks. Imagine be able to reserve a lambda between and your friend 1000 km away. It's like having a dedicated fiber. Just plug your equipment at both ends.
Check the PPT of this workshop on the subject for more details:
Well, many of the technologies developped on this network will be transfered to the Internet some day.
In fact, you can see Internet 2 as a part of the internet. It's only that the BGP routing is done in a manner that it's only data between two academic nodes that pass through it.
Ex.: 1) college.edu slashdot.org -- Commercial internet 2) college.edu othercollege.edu -- Internet 2
Oh.. and we call Internet 2 that way in the US only. In Canada for example, it's CA*net4, but it's the same thing.
They are selling the motor-wheel, you can find more information about it on the web site of a Hydro-Quebec subsidary M4.
The project of building a complete car from scratch was abandonned because it needs massive investments. They figured it would be easier to find partners and license this technology. GM bought a license.
Another reason why they prefer licensing the technology is that is may be not a great idea to put all this weight in the wheel. Taking a bump could easily destroy the suspension.
The author of the article assumes that the power supply is running at full capacity. This is a good approximation of an upper bound, but the actual consuption is only a fraction of that.
It's like calculating the mpg of a car using the flow rate of the gas pump and the maximum speed on the speedometer
I worked on a Ogg on FPGA project as an end of study project in university. It's not quite difficult, but it takes a lot of time for a student without experience;-) I based my project on the LEON-2 open source processor and I coded a MDCT coprocessor for better performances (I was inspired by the oggonachip guys). Great fun!
I did not finished this project, but I'm sure there's other somewhere like me who tried and maybe a couple succeeded.
I downloaded Knoppix yesterday night using BitTorrent. The speed was great, I was really impressed. When completed, BitTorrent reported sucess.
But... the checksum was bad. BitTorrent didn't warned me of anything. I don't know what happened, is it the original iso that was bad or is it a BitTorrent bug? BitTorrent should at least have a way to protect the integrity of the file in case an evil node contaminates the pool...
I will try BitTorrent again because I think it's a great idea. Maybe it's just not mature yet.
An interesting interview with Moby in Shift.com magazine:
-----
(...) after hearing that songs from Play had been mysteriously filtered out of Napter last year, he threatened to protest by running through the streets of New York wearing nothing but a Napster T-Shirt.
"Being opposed to file-sharing is like being opposed to the tide: You can stand on the beach and yell at the tide, but it's just a fact of life. And it's going to spread" he says. "The two things that aren't going to go away are publishing [copyrights on songs] and touring. If I were in the business, or I wanted to be in the music business, that's what I would be looking at"
Any way you slice it, the cost per passenger mile is much higher by rail than by car. Putting it under government control simply hides the costs.
The road system is under government control.
Do you think car would be more economical if the users had to pay for the road infrastructure? The taxpayers pay the concrete, the highway patrol, the management and you only have to pay your car and your gas...
You have to calculate the environmental and social costs too.
My theory is that eventually this evolve into 2 Internets. One used by businesses and *maybe* individuals. The other is the existing one that will be used by the Internet underground, or those who cannot afford the New Internet.
I don't think we can support two internet. Are those two networks separated? If I want the new internet, I will have to continue to pay for the old to visit the "old" sites? Will I have to disconnect and reconnect like I dual boot my OS? If corporations move to the new internet, who will fund the old backbones?
I think the new network will be built on the top of the old one. They're already building it, it's IPv6 with QoS and it should solve most of the issues pointed in the article. The "important" traffic (from big corporations) will use the "new" internet and the last 2 hop will be the same than the "old" internet.
Caida is producing dynamic graphs of the code red spread. It seems that there is about 50% less infected host than last time. The worm progression seems to have stopped, probably that all the machine with the IIS bug are now infected.
Slashdot Mirror
Sorry for misreading your questions. The article talks about blockchains in general, it does not refer to one in particular, so it is not possible to give specific answers to your questions.
When people talk about "general purpose" blockchains, usually they have in mind Ethereum (which uses cpu-resistant POW, to make sure ASICs are not economical. Planning to transition to POS) and Hyperledger which uses PBFT. My understanding of Hyperledger is that is assumes that most nodes are acting in good faith, but I might be wrong.
It's a VM, but it's not free. You need to pay the cost of CPU processing, so to be able to be 'unkillable', a virus will need to be able to generate revenues on its own, to be able to support its "life-style".
But yeah, being turing-complete is a major challenge. Ethereum sustained a major DOS attack a few months ago because some opcodes were mispriced. An attacker was able to bog down the network with a relatively small investment.
Yup that's the biggest hurdle right now but multiple ideas are being explored. The one that I personally find the most promising is "sharding", an idea developed to allow the Ethereum blockchain to scale massively. In a nutshell, they will split the blockchain in multiple shards and allow transactions between them.
More details here: https://github.com/ethereum/wi...
Woah that's a lot of questions. Let me try to answer the first two:
What is the "proof of work" used by the blockchain to decide which node gets to commit to the permanent blockchain record?
A complex mathematical question that takes a long time to answer. Complexity of the question is adjusted dynamically to aim for a regular block "commit" like you say. There are alternatives to PoW, like Proof Of Stake (PoS) where you "stake" an amount of money that you will lose if you cheat.
How will the blockchain handle if a pool of nodes consisting of > 50% of the computing power for proof of work decides to "double spend" or alter a blockchain record?
It happened on smaller, less popular blockchains, where the investment to hire the necessary computer power was relatively small. That's why bigger, more popular blockchains are considered more "secure". For bitcoin, that would cost hundreds of millions and you might gain at most thousands of dollars. Double-spending will be discovered a few blocks later, that don't leave you a lot of time to cash out the bitcoins.
Actually, it is quite the opposite. Blockchain platforms, like Ethereum, are being built to address the re-centralization problems that you describe.
Ethereum aims to build a centralized "world-computer" with 3 main components:
- ethereum blockchain: decentralized turing-complete VM, with built-in ability to create cryptocurrencies
- swarm: decentralized storage, similar to IPFS
- whisper: decentralized messaging
The project is still in its infancy, but it's already usable. Still not 100% decentralized as it still relies on HTTP and DNS, and scaling is on the roadmap. Just to give you an idea of what this platforms makes possible, here are examples of projects already launched or in alpha:
- OasisDEX: A decentralized cryptoasset exchange
- ENS: Decentralized Naming Service, to replace DNS
- uPort: self-sovereign identity
- Everex: remittance for migrant workers
According to this:
"Recharge through USB or universal AC adapter"
Sorry, I don't want to have to think about charging my watch. I expect to be able to keep it on my wrist a couple of months, at least.
Jabref is also able to manage your PDF and PS files. It's great if you want to keep an electronic archive of the papers you cite.
Definitively the best bibtex editor I came accross.
Quebecord was forced to sell TQS.
They own major TV channel, TVA. What is the other?
Here is a torrent for the 4MB video. I'll keep it up for 24-48 hours.
48InchCrash.mpg.torrent
Please seed.
They don't have to inspect de packet content to determine what's the kind of traffic. They could use the stats that the routers gather.
l owscan/
I don't know how they did it, but here's how I would proceed:
You need is an access to the NetFlow data of a couple of Cisco routers on the ISP network. This data contains statistics about the connections between two IP adress like the port numbers, packets/bytes numbers and timestamps.
Then you setup a server to poll regularly the routers, aggregate the data and generate nice graphs using a software like FlowScan:
http://www.caida.org/tools/utilities/f
Nothing complicated, the difficult part is to explain to the ISP why they should enable NetFlow and give you access. (It adds a little load on the router).
Anonymous poster is totally right. Internet2 runs on IPv4, but there is experimental IPv6 tunnels. They may have a couple experimental dedicated link these days, but that's all.
Lightpaths is an exciting development in networks. Imagine be able to reserve a lambda between and your friend 1000 km away. It's like having a dedicated fiber. Just plug your equipment at both ends.
Check the PPT of this workshop on the subject for more details:
Well, many of the technologies developped on this network will be transfered to the Internet some day.
In fact, you can see Internet 2 as a part of the internet. It's only that the BGP routing is done in a manner that it's only data between two academic nodes that pass through it.
Ex.:
1) college.edu slashdot.org -- Commercial internet
2) college.edu othercollege.edu -- Internet 2
Oh.. and we call Internet 2 that way in the US only. In Canada for example, it's CA*net4, but it's the same thing.
They are selling the motor-wheel, you can find more information about it on the web site of a Hydro-Quebec subsidary M4.
The project of building a complete car from scratch was abandonned because it needs massive investments. They figured it would be easier to find partners and license this technology. GM bought a license.
Another reason why they prefer licensing the technology is that is may be not a great idea to put all this weight in the wheel. Taking a bump could easily destroy the suspension.
The author of the article assumes that the power supply is running at full capacity. This is a good approximation of an upper bound, but the actual consuption is only a fraction of that.
It's like calculating the mpg of a car using the flow rate of the gas pump and the maximum speed on the speedometer
I did not finished this project, but I'm sure there's other somewhere like me who tried and maybe a couple succeeded.
I downloaded Knoppix yesterday night using BitTorrent. The speed was great, I was really impressed. When completed, BitTorrent reported sucess.
But... the checksum was bad. BitTorrent didn't warned me of anything. I don't know what happened, is it the original iso that was bad or is it a BitTorrent bug? BitTorrent should at least have a way to protect the integrity of the file in case an evil node contaminates the pool...
I will try BitTorrent again because I think it's a great idea. Maybe it's just not mature yet.
According to their site, SomaFM will resume broadcoast soon !! yay!
0.70$ per song per thousand listeners seems to be reasonable for small webcasters.
An interesting interview with Moby in Shift.com magazine:
-----
(...) after hearing that songs from Play had been mysteriously filtered out of Napter last year, he threatened to protest by running through the streets of New York wearing nothing but a Napster T-Shirt.
"Being opposed to file-sharing is like being opposed to the tide: You can stand on the beach and yell at the tide, but it's just a fact of life. And it's going to spread" he says. "The two things that aren't going to go away are publishing [copyrights on songs] and touring. If I were in the business, or I wanted to be in the music business, that's what I would be looking at"
(...)
---
Shift v10.2, p.35 (summer 2002)
The road system is under government control.
Do you think car would be more economical if the users had to pay for the road infrastructure? The taxpayers pay the concrete, the highway patrol, the management and you only have to pay your car and your gas...
You have to calculate the environmental and social costs too.
No small feat, there. Too bad they didn't use regenerative aerobraking [nrel.gov]?we might have gotten the spacecraft back.
They talk about electric car breaking, I can't understand how it could apply to aerobraking. Do you have a better link?
There are many ways to do so:
Using something like "tail -f nameoflog.log | scriptsend.pl" would work well.
---
I don't think we can support two internet. Are those two networks separated? If I want the new internet, I will have to continue to pay for the old to visit the "old" sites? Will I have to disconnect and reconnect like I dual boot my OS? If corporations move to the new internet, who will fund the old backbones?
I think the new network will be built on the top of the old one. They're already building it, it's IPv6 with QoS and it should solve most of the issues pointed in the article. The "important" traffic (from big corporations) will use the "new" internet and the last 2 hop will be the same than the "old" internet.
http://www.caida.org/dynamic/analysis/security/cod e-red/index.html
But, like the old banner ads, we'll get used to and we will stop seeing them.