Like records of land ownership. Creating and maintaining incorruptible registers of land titles is a huge – and mostly unsolved – problem for developing countries. So when the government of Honduras launched an investigation into whether a blockchain-based land registry could solve it, the non-geek world sat up and began to take notice. The unmistakable message was that this technology could be much more useful than merely securing cryptocurrencies. It might actually turn out to be one of the biggest IT inventions of our time.
Rutter said the initial focus would be to agree on an underlying architecture, but it had not yet been decided whether that would be underpinned by bitcoin’s blockchain or another one, such as one being built by Ethereum, which offers more features than the original bitcoin technology.
Once that had been agreed on, Rutter said, the first use of the technology might be the issuance of commercial paper on the blockchain.
GHash is in a position to exercise complete control over which transactions appear on the blockchain and which miners reap mining rewards. They could keep 100% of the mining profits to themselves if they so chose. Bitcoin is currently an expensive distributed database under the control of a single entity, albeit one that requires constantly burning energy to maintain — worst of all worlds.
What exactly are colored coins? I’ve tried understanding, but I don’t quite get it yet . . . Do any examples exist?
Colored coins are a method to track the origin of bitcoins, so that a certain set of coins can be set aside and conserved, allowing a party to acknowledge them in various ways. Such coins can be used to represent arbitrary digital tokens, such as stocks, bonds, smart property and so on.
The colored coins protocol is decentralized just like Bitcoin, but the current effort to develop an implementation is done under the BitcoinX project (tentative name), which also aims to provide some related services.
As this is still under development, you will not find any existing examples.
You can read more about it in Overview of colored coins (work in progress).
One of the most difficult problems in computer science is reversing a secure hash (finding an input text for a given output, the digital signature). Let me explain this problem in simple terms. Let’s assume the wealthy but terminally ill Alice wrote her will and stored it on her computer. Knowing that a computer can be hacked and the will can be altered, Alice digitally signed her will with the secure hash algorithm SHA-256. She then emailed the digital signature to all her friends, allowing them to check the validity of the document. Bob wants to hack into the computer and change Alice’s will so that he becomes the sole beneficiary, but he faces a problem: he needs to change the will in such a way that the widely distributed SHA-256 signature stays the same. Otherwise, everybody realizes that the will has been forged. This is the computationally difficult problem of reversing or brute-forcing SHA-256, or finding an input that matches a predefined output. Satoshi famously decided that in order to find a new block, people all over the world need to compete in reversing SHA-256, turning block creation into a global lottery.
Once very popular among Bitcoin miners, but now somewhat dated, the Radeon HD 5830 card boasts 1120 stream processing units. But that doesn’t mean it literally has 1120 separate cores. Rather, the GPU employs 224 SIMD cores, each of which sports five ALUs operating in parallel (VLIW5).
A coalition of bitcoin businesses — including bitcoin wallet-makers Coinbase and Blockchain — quickly put out a statement as news of the hack spread. “This tragic violation of the trust of users of Mt. Gox was the result of one company’s abhorrent actions and does not reflect the resilience or value of bitcoin and the digital currency industry,” they said. “There are hundreds of trustworthy and responsible companies involved in bitcoin.”
Bitcoin mining equipment company KnC Miner has begun construction on its new facility in Boden, about 10 miles down the road from Facebook’s server farm in Lulea. The data center is being built in a facility previously used as a helicopter hangar for the Swedish armed forces. It will be retrofitted to house thousands of custom Bitcoin mining rigs built by KnC Miner, one of a host of new vendors that has emerged to serve the growing market for Bitcoin hardware.
KnC Miner is based in Stockholm, Sweden and has established a leadership position in Bitcoin mining rigs powered by ASICs (Application Specific Integrated Circuits) to crunch data for creating and tracking bitcoins. The company says it has sold $75 million in hardware since June, with customers in 120 countries.
An attacker that controls more than 50% of the network’s computing power can, for the time that he is in control, exclude and modify the ordering of transactions. This allows him to:
- Reverse transactions that he sends while he’s in control. This has the potential to double-spend transactions that previously had already been seen in the block chain.
- Prevent some or all transactions from gaining any confirmations
- Prevent some or all other miners from mining any valid blocks
via Weaknesses – Bitcoin.
With less than 50%, the same kind of attacks are possible, but with less than 100% rate of success. For example, someone with only 40% of the network computing power can overcome a 6-deep confirmed transaction with a 50% success rate.
This paper proposes a new microblogging architecture based on peer-to-peer networks overlays. The proposed platform is comprised of three mostly independent overlay networks. The first provides distributed user registration and authentication and is based on the Bitcoin protocol. The second one is a Distributed Hash Table DHT overlay network providing key/value storage for user resources and tracker location for the third network. The last network is a collection of possibly disjoint “swarms” of followers, based on the Bittorrent protocol, which can be used for efficient near-instant notification delivery to many users. By leveraging from existing and proven technologies, twister provides a new microblogging platform offering security, scalability and privacy features. A mechanism provides incentive for entities that contribute processing time to run the user registration network, rewarding such entities with the privilege of sending a single unsolicited “promoted” message to the entire network. The number of unsolicited messages per day is defined in order to not upset users.