A blockchain block chain, is a growing list of records, called blocks, that are linked using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, transaction data. By design, a blockchain is resistant to modification of the data, it is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way". For use as a distributed ledger, a blockchain is managed by a peer-to-peer network collectively adhering to a protocol for inter-node communication and validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without alteration of all subsequent blocks, which requires consensus of the network majority. Although blockchain records are not unalterable, blockchains may be considered secure by design and exemplify a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been claimed with a blockchain. Blockchain was invented by a person using the name Satoshi Nakamoto in 2008 to serve as the public transaction ledger of the cryptocurrency bitcoin.

The identity of Satoshi Nakamoto is unknown. The invention of the blockchain for bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server; the bitcoin design has inspired other applications, blockchains that are readable by the public are used by cryptocurrencies. Blockchain is considered a type of payment rail. Private blockchains have been proposed for business use. Sources such as Computerworld called the marketing of such blockchains without a proper security model "snake oil"; the first work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta, they wanted to implement a system. In 1992, Bayer and Stornetta incorporated Merkle trees to the design, which improved its efficiency by allowing several document certificates to be collected into one block; the first blockchain was conceptualized by a person known as Satoshi Nakamoto in 2008. Nakamoto improved the design in an important way using a Hashcash-like method to timestamp blocks without requiring them to be signed by a trusted party and introducing a difficulty parameter to stabilize rate with which blocks are added to the chain.

The design was implemented the following year by Nakamoto as a core component of the cryptocurrency bitcoin, where it serves as the public ledger for all transactions on the network. In August 2014, the bitcoin blockchain file size, containing records of all transactions that have occurred on the network, reached 20 GB. In January 2015, the size had grown to 30 GB, from January 2016 to January 2017, the bitcoin blockchain grew from 50 GB to 100 GB in size; the ledger size had exceeded 200 GiB by early 2020. The words block and chain were used separately in Satoshi Nakamoto's original paper, but were popularized as a single word, blockchain, by 2016. According to Accenture, an application of the diffusion of innovations theory suggests that blockchains attained a 13.5% adoption rate within financial services in 2016, therefore reaching the early adopters phase. Industry trade groups joined to create the Global Blockchain Forum in 2016, an initiative of the Chamber of Digital Commerce. In May 2018, Gartner found that only 1% of CIOs indicated any kind of blockchain adoption within their organisations, only 8% of CIOs were in the short-term "planning or active experimentation with blockchain".

A blockchain is a decentralized and oftentimes public, digital ledger, used to record transactions across many computers so that any involved record cannot be altered retroactively, without the alteration of all subsequent blocks. This allows the participants to verify and audit transactions independently and inexpensively. A blockchain database is managed autonomously using a peer-to-peer network and a distributed timestamping server, they are authenticated by mass collaboration powered by collective self-interests. Such a design facilitates robust workflow where participants' uncertainty regarding data security is marginal; the use of a blockchain removes the characteristic of infinite reproducibility from a digital asset. It confirms that each unit of value was transferred only once, solving the long-standing problem of double spending. A blockchain has been described as a value-exchange protocol. A blockchain can maintain title rights because, when properly set up to detail the exchange agreement, it provides a record that compels offer and acceptance.

Blocks hold batches of valid transactions that are encoded into a Merkle tree. Each block includes the cryptographic hash of the prior block in the blockchain; the linked blocks form a chain. This iterative process confirms the integrity of the previous block, all the way back to the original genesis block. Sometimes separate blocks can be produced concurrently. In addition to a secure hash-based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher score can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks. Peers supporting the database have different versions of the history from time to time, they keep only the highest-scoring version of the database known to them. Whenever a peer receives a higher-scoring version they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute g

Ireland–Kosovo relations

Irish–Kosovan relations are foreign relations between Ireland and the Republic of Kosovo. Kosovo declared its independence from Serbia on 17 February 2008 and Ireland recognised it on 29 February 2008. On 20 May 2011 Ireland's ambassador to Budapest, Hungary John Deady submitted his credentials to Pristina, Kosovo. In 1999, Ireland took 1,000 refugees; this number was criticised by the United Nations Human Rights Commissioner and former President of Ireland Mary Robinson who called it, the complacency and selfishness of the Irish for accepting only 1,000 refugees from Kosovo. Ireland has sent peacekeepers to Kosovo, it was the first time Ireland has commanded such a force in a NATO-led United Nations mandated peace support operation. In 2007, Irish Brigadier General Gerry Hegarty, took over command one of the five multi-national task forces. A ceremony was held in Kosovo at noon on 15 April 2010 to mark the end of Ireland's major involvement in the KFOR peace mission. Foreign relations of the Republic of Ireland Foreign relations of Kosovo Ireland–NATO relations Notes: References

Boyd Brown

H. Boyd Brown is a former Democratic member of the South Carolina House of Representatives from Fairfield County, South Carolina. Brown graduated from the University of South Carolina with a degree in Political Science. Brown comes from a family of politicians, he was a third generation member of the South Carolina House of Representatives, is the grandson of Walter B. Brown, a former legislator and railroad executive, his father David was one of the longest serving County Commissioners in South Carolina, served multiple terms as Chairman of Fairfield County Council. His uncle, Judge Walter Boyd "B" Brown, Jr. was a state Family Court Judge until the time of his death, his great-grandfather, Boyd Brown, was a member of the South Carolina House of Representatives from Fairfield County, served as Chairman of the House Labor and Commerce Committee. Brown's older brother serves on Town Council in South Carolina. In 2008, Brown defeated incumbent Fairfield County School Board member Annie McDaniel with 54% in the Democratic Primary, cruised to election in November, defeating his Republican challenger Sean Schaeffner with 81% of the electorate.

At the time of his election, he was the youngest elected state lawmaker in the United States. Upon taking office, Brown was appointed to the House Agriculture, Natural Resources and Environmental Affairs Committee. Brown's seat was up for re-election in 2010. In the Democratic seat, he defeated a June primary rival before running unopposed in November. In his second term, Brown was appointed to the powerful House Judiciary Committee. Brown surprised many by announcing that he would not seek a third term in the South Carolina General Assembly. Wanting to start a successful career in the private sector, Brown issued a press release announcing his departure from the South Carolina House of Representatives. In a farewell address in June 2012, Brown talked about the issues important to his generation; the speech garnered national attention, with The Washington Post referring to him as "The Voice of a Generation." Brown resides in Columbia, South Carolina, works in commercial real estate and owns a bipartisan government affairs firm.

In 2015, he was appointed by the Republican President Pro Tempore of the State Senate to serve on the nine member board of the South Carolina Conservation Bank. Brown served on the board of his local hospital, Fairfield Memorial in Winnsboro, South Carolina, he was one of South Carolina's three members on the Democratic National Committee from 2012-2016