{"id":58,"date":"2018-06-25T12:03:00","date_gmt":"2018-06-25T12:03:00","guid":{"rendered":"https:\/\/www.emruocco.com\/lesperienza-di-enzo-mattia-ruocco-nel-mondo-digitale\/"},"modified":"2025-12-08T22:51:34","modified_gmt":"2025-12-08T22:51:34","slug":"la-tecnologia-blockchain","status":"publish","type":"post","link":"https:\/\/www.emruocco.com\/en\/la-tecnologia-blockchain\/","title":{"rendered":"Blockchain technology"},"content":{"rendered":"
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Blockchain technology<\/h2>\n

How it works and why it's revolutionary<\/h2>\n<\/header>\n

In 2018, for my high school thesis, I decided to delve deeper into one of the technologies
most discussed in recent years: the blockchain<\/strong>, born with Bitcoin<\/strong>
and then taken up again in many other contexts.<\/p>\n

In this article, I review the fundamental concepts: what is a blockchain, how it works "behind the scenes"\u201c
and why it is considered so safe and revolutionary.<\/p>\n

What is blockchain?<\/h3>\n

Blockchain can be seen as a distributed public ledger<\/strong>:<\/p>\n

    \n
  • it's a register<\/strong> because it contains the list of all transactions (in the case of Bitcoin, the movements of the cryptocurrency);<\/li>\n
  • \u00e8 public<\/strong> because anyone can download the blockchain and read its contents;<\/li>\n
  • \u00e8 distributed<\/strong> because there is no central server: the copy of the registry is present on many nodes in the network.<\/li>\n<\/ul>\n

    This network is a peer-to-peer (P2P) network<\/strong>: each connected computer participates in sharing
    of information, without the need for a central authority.<\/p>\n

    Blocks chained together<\/h3>\n

    The data is not saved in a single continuous file, but in blocks<\/strong>.
    Each block contains:<\/p>\n

      \n
    • a set of transactions,<\/li>\n
    • a reference to the previous block,<\/li>\n
    • a control value (the\u2019hash<\/strong>) calculated on all data in the block.<\/li>\n<\/ul>\n

      The blocks are concatenated<\/strong> because each contains the hash of the previous block.
      In this way a real blockchain<\/strong>: blockchain<\/em>.<\/p>\n

      If someone were to modify even just one piece of data within a block, it would change its hash and consequently
      all the hashes of subsequent blocks would have to be recalculated. It is precisely this mechanism that makes
      the changes so difficult.<\/p>\n

      \"\"<\/h2>\n

      Hash, nonce, and computational work<\/h3>\n

      The \u201cglue\u201d between the blocks is a cryptographic hash function<\/strong>.
      This is a function that:<\/p>\n

        \n
      • takes block data as input (transactions, timestamp, reference to the previous block, etc.);<\/li>\n
      • returns a long alphanumeric string (the hash);<\/li>\n
      • \u00e8 easy<\/strong> to be calculated in one sense, but impossible<\/strong> to be reversed
        (The hash cannot be traced back to the original data).<\/li>\n<\/ul>\n

        In the case of Bitcoin, calculating the hash just once is not enough to consider a block valid:
        the generated hash must start with a certain number of leading zeros<\/strong>.<\/p>\n

        To obtain a hash with these characteristics, a variable number called nonce<\/strong>.
        The process is this:<\/p>\n

          \n
        1. take the block data,<\/li>\n
        2. a nonce value is added,<\/li>\n
        3. the hash is calculated,<\/li>\n
        4. If the hash does not have the required number of leading zeros, change the nonce and try again.<\/li>\n<\/ol>\n

          This process continues by trial and error<\/strong>, until a nonce is found that produces a valid hash.
          All this research is the famous computational work<\/strong>: it takes time and energy,
          because you have to try so many combinations.<\/p>\n

          Who does this job? The miners.<\/h3>\n

          The nonce lookup work is done by the miner<\/strong>.<\/p>\n

            \n
          • In theory, whoever<\/strong> in the network can become a miner.<\/li>\n
          • In practice, today we need machines with extremely high computing power to compete with others.<\/li>\n<\/ul>\n

            Miners compete to be the first to find the correct nonce for a new block.
            Who can validate the block:<\/p>\n

              \n
            • communicates it to the network,<\/li>\n
            • he comes rewarded<\/strong> with new cryptocurrency (in the case of Bitcoin, with newly issued bitcoins).<\/li>\n<\/ul>\n

              This mechanism is called Proof of Work<\/strong>:
              proof that some computational work has been done to add a block to the chain.<\/p>\n

              \"\"<\/p>\n

              Why blockchain is considered secure<\/h3>\n

              Blockchain security arises from a combination of several factors:<\/p>\n

                \n
              • Dependency between blocks<\/strong>
                Each block contains the hash of the previous one. Altering one block would force all subsequent blocks to be recalculated.<\/li>\n
              • Distributed network<\/strong>
                The blockchain is stored on many nodes in the network. There is no single point of attack or corruption.<\/li>\n
              • Longest chain rule<\/strong>
                The network accepts the longer chain<\/strong> (the one that represents the largest quantity
                of computational work done). An altered version of the blockchain, shorter or with less work, is discarded.<\/li>\n
              • 51% of honesty<\/strong>
                The system is safe as long as at least the 51%<\/strong> of computing power is controlled by honest nodes.
                To truly attack the blockchain, one would need to control the majority of the total computing power:
                an extremely expensive and difficult undertaking.<\/li>\n<\/ul>\n

                Why blockchain is revolutionary<\/h3>\n

                The real revolution is not just the cryptocurrency itself, but the fact that the blockchain allows:<\/p>\n

                  \n
                • have a public register<\/strong> that no one controls alone;<\/li>\n
                • guarantee data integrity<\/strong> without trusting a single central entity;<\/li>\n
                • coordinate financial transactions between strangers, using mathematics and cryptography
                  instead of personal trust.<\/li>\n<\/ul>\n

                  In the case of Bitcoin, this translates into a digital currency<\/strong> which does not depend on central banks
                  or traditional intermediaries. But the same idea of a "distributed ledger" can be applied to many other areas:
                  contracts, traceability, digital asset management and much more.<\/p>\n

                  \"\"<\/p>\n<\/section>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"

                  La tecnologia blockchain Come funziona e perch\u00e9 \u00e8 rivoluzionaria Nel 2018, in occasione della tesina delle superiori, ho deciso di approfondire una delle tecnologiepi\u00f9 discusse degli ultimi anni: la blockchain, nata con Bitcoine poi ripresa in molti altri contesti. In questo articolo ripercorro i concetti fondamentali: cos\u2019\u00e8 una blockchain, come funziona \u201cdietro le quinte\u201de perch\u00e9 […]<\/p>\n","protected":false},"author":1,"featured_media":5059,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[83],"tags":[87,84,86,85],"class_list":["post-58","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blockchain-nft","tag-algoritmi","tag-blockchain","tag-coding","tag-nft"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t