Over the past few days, there have been various rumors regarding an impending 51% attack against the Ethereum Classic network.Although some earlier attempts remained nothing but speculation, 51Pool is forging ahead with its plans to destroy the ETC network.This goes to show how some people in the Ethereum community respond when the going gets tough.Ever since has proven to be able to stand on its own two legs, for now, the Ethereum community has been rather hostile towards this project.That is rather strange, considering both ecosystems are one and the same, albeit one has a solution which the other did not implement.51Pool Shows True Colors of Some Ethereum Holders Some of the community members have taken it upon themselves to come up with a plan of action that will ultimately destroy the ETC network, or at least try to.The project is called 51Pool, which is currently mining Ethereum at 0.25% fees.It originally started at 0% fees, but that was not sustainable apparently.The objective of 51Pool is rather simple: gather enough mining power to perform an attack on the ETC network.

Right now, Ethereum Classic Mining power sits at 464 GH/s, so it will take some time until something can happen.That being said, the pool will continue to mine ETH for now until sufficient hashrate can be achieved.If this ever were to be the case – and the Ethereum community would better hope it won’t be – 51Pool will attempt to 51% attack ETC as many times as necessary.By using a modified client, the pool owner hopes to achieve his attack and forge mined blocks, so the pool gets all of them.As to why people should join 51Pool in their efforts, the answer is rather straightforward: – Prove ETC is not immuteable – Kill off ETC hash rate to destroy network – Remove uncertainty in ETH vs ETC – Increase ETH’s market value – See how much anti-forkers think “code is law” – Be a part of history It is evident for everyone to see this is not an effort representing the entire Ethereum community.Unfortunately, every single supporter will be caught in the crossfire of repercussions that will undoubtedly follow these attacks, if they are ever executed.

The Ethereum developers can prevent all of this mess from happening if they wanted to.It will be interesting to see if they decide to intervene or not.commits branches release Fetching contributors Latest commit 79a973f Mar 9, 2016 Document potential media source manipulation mitigation Permalink README.md JsJob Ethereum Experiment in building a computational market on Ethereum blockchain, using out-of-chain execution of JavaScript in browser-sandbox using JsJob, and distributed data storage on IPFS.bitcoin arrest indiaMotivation As of 2016, the conventional approach to large-scale, compute-intensive services is: Persist data in a relational or NoSQL database Farm out compute work using a message broker like RabbitMQ Server code exposing an HTTP API Clients provide user interface(s) on top of this api Deploy it in a private network at some cloud provider This works, and there exists lots of best-practice around building an maintaining such a service.bitcoin extension wiki

However it is a heavily centralized solution, with associated drawbacks of single controlling entities.A primarily decentralized approach may have following benefits: Increased robustness from service disruption due to failure in central providers (Heroku/AWS) Avoids single actors being able to take service away from users (like a local government and/or ISP).Service may even be maintained independently of the initial creator.Geographical distribution of the service does not require.buy litecoins euMay give better performance for (some) users Potential of cost savings, by enabling small-scale participation with reducing friction.bitcoin kurs liveSome users and volunteers may be willing to take some of the costs, possibly due to improved service quality, or because they are able to externalize it.bitcoin precio grafica

Like free/sunk electricity or compute equipment costs.Derivative, spin-off and value-add services are more incentivized because of less central control Status Proof-of-concept.Can distribute jobs through Ethereum blockchain that can be picked up by workers and executed in browser sandbox.There is no reward payments and no security implemented, and only tested on non-production network and data.Ethereum contract is quick&dirty Input, code and results are distributed using IPFS dapp webui and nodejs CLI tool can post jobs to agency worker can listen for jobs and execute them (in PhantomJS) Tested with TestRPC virtual network, and go-ethereum on Morden testnet See the TODO section for milestones and next steps.mercado bitcoin paypalInstalling npm install Developing Start Ethereum testing client, with JSON-RPC enabled../node_modules/.bin/testrpc Run tests npm test We use the truffle framework, accessed through wrapper ./truffle script.

Refer to their documentation for more details on usage.Deploying a JobAgency ./truffle deploy Running a worker Run an Ethereum node.Make sure account[0] is unlocked, that JSON-RPC is enabled.geth --rpc --unlock 0xd87e13619.... Run an IPFS node, on port 8090 ipfs config Addresses.Gateway /ip4/127.0.0.1/tcp/8090 ipfs daemon Run the actual worker.Optionally specify address of the JobAgency to use ./bin/worker [0x2f431...] Running a job poster Run an Ethereum node.For webui CORS also needs to be allowed.geth --rpc --unlock 0xd87e13619.... --rpccorsdomain="*" Serve the webui, then open browser at http://localhost:8080 ./truffle serve Alternatively, use the CLI tool: ./bin/postjob CODEHASH INPUTHASH [JobAgency address] Architecture Parts Job: input data (IPFS hash), code (IPFS hash, to some JavaScript), result (IPFS hash).Agency: Posts new Jobs, by logging them Agent: Subscribed to Agency, waiting for new Job to perform.

Interactions On new Job, Agent downloads the input and code from IPFS, starts the computation.When Agent completes a computation done, uploads results to IPFS, then updates the Job contract.The Jobverifies the result, and assuming it was correct, credits the Agent.Once in a while (eg weekly or when above N credits), the Agency pays out the credits of Agents as Ether.TODO Proof-of-concept Unhardcode script/polyfill Unhardcode accounts used Add end2end tests Add some example application(s), which has some code+data up on IPFS, uses this to compute things Document and publish blogpost(s) Support options data as part of job?Production ready Defined & implemented basic security strategy Tested a lot on the testnet Integration point for, and existance of, functional tests of results A way to tune Ethereum/centralized work-balance (manual or automated) Distributed ready Docker images available, ready-to-run on x86 cloud/home server Ready-to-run SD card image for Rasperry Pi Worker ready-to-include in browser/mobile applications Security Threat model In the case of producing webpages, an attacker returning bad results could for instance: Put ads on pages Put in obscene content Remove some or all content, for censoring or denial-of-service Try to steal credentials from host-scoped storage (localstorage) Attacks can also happen by attacking the contracts themselves.

This could allow to bypass security mechanisms to perform any of the above, as well as steal the Ether currently in the system.This means fairly interesting for attackers with finanical, political and fame motivations.Potential mechanisms Functional verification (tests) of results.Trusted workers replicating the work, comparing it.For some small, randomized portion of the jobs."ticket control" Reputation system.Note, may still be open for Sybil attack Withholding payout of performed work until a lot of work is verified Require a deposit, for punishment in case of bad/contested results.User review/approval of output, exposed to visitors Not allow executable code (at least not Turing complete) in results.For websites, maybe AMP HTML?Media embedding (iframe, images) is also a vector, though potentially mitigated by comparing to media sources in input data.Related work Ethereum computation market From Smart Contracts to Courts with not so Smart Judges.