The What’s Up with Science? blog series offers a deep dive into science, technology, and innovation topics on the minds of the public. The series matches technical explanations with relatable analogies to explain opportunities and answer the ultimate question: Why should we care?
If you’ve ever been concerned about preserving the authenticity of information, you must tip your cap to the ingenuity of the Founding Fathers in the (entirely fictional) movie National Treasure. In the film, the Founders needed to ensure that clues leading to the Templar Treasure would never be destroyed or altered, while guaranteeing that only certain people could read them. Their most memorable solution was to record one of those clues in invisible ink on the back of a document that would be protected forever: the Declaration of Independence.
As a huge fan of National Treasure, I’m really glad that blockchain didn’t exist in 1776, because this technology would have ruined the movie by protecting the Templar Treasure without puzzle-solving and historical anecdotes. Blockchain was developed to digitally store information while preserving its authenticity, all by “chaining” the information together.
The chain links, known as “blocks,” are comprised of the information (i.e., text, numbers, pictures, basically anything) being stored. Blocks are added chronologically to the ever-growing chain. When a new block is appended, it becomes inextricably linked to the information recorded in the block preceding it. That means altering the information in one block would alter the information in every block that follows.
This makes tampering with data in a blockchain very difficult, and here’s why. Remember how, in the movie, the Templar Treasure was secured using distributed clues, whose locations ranged from a ship in the Arctic, to the Declaration at the National Archives, to Independence Hall in Philadelphia? A blockchain is similarly secured because it’s decentralized—it isn’t stored in a single place. A copy of the chain is distributed across every computer that has ever added a block.
To oversimplify, this essentially means altering an existing block on one computer prompts the rest of the computers to delete that alteration, reinstating the unaltered version of the chain. Blockchain operates via consensus—all the computers must agree on a change for it to stick—resulting in a tamper-proof and authentic record. If you’re interested in the details, read more here.
Even though a blockchain is stored on many computers, it does a pretty good job of ensuring privacy. Information can only be added or accessed if you have two keys, long strings of random letters and numbers. This is a lot like how there were two “keys” required to understand the (again, entirely fictional) clues on the back of the Declaration of Independence. Key #1 was lemon juice and heat, which exposed the invisibly inked cipher. Key #2—the Silence Dogood letters—was then used to decode it.
The promise of protected records and privacy makes blockchain an intriguing technology. Despite remaining challenges like scalability, interoperability between different blockchains, and the fact that records cannot be deleted, the technology is used in numerous ways. You may be familiar with applications in financial technology, or “fintech,” but that’s just the tip of the iceberg.

Supply chain management could also be revolutionized by blockchain. We noted a food-tracing application in a previous article, and many other industries could similarly benefit from confirming product origins or accounting for each step in manufacturing. You could imagine, perhaps, a role for blockchain in tracking PPE distribution during the COVID-19 pandemic. Another example dates back to 2017, when a London designer became the first to use blockchain in clothing production, aiming to increase consumer confidence in their garments.
The technology has uses beyond manufacturing and distribution, too. In the healthcare sector, blockchain could give patients greater access to their health records, while the assurance of privacy could allow for more complete—yet HIPAA-compliant—disease tracking. In the realm of humanitarian aid, blockchain can help manage information, track supplies, and coordinate assistance. These are only a few examples.
Unsurprisingly, the U.S. Government has noticed these meaningful and diverse uses. That’s why the State Department and other agencies continue to think about the role that blockchain can play in protecting intellectual property and innovation, ensuring effective humanitarian and development assistance, including marginalized communities in the global economy, and improving trust in information management.
Like many technologies, the utility of blockchain will expand as it matures, while new applications will be as intriguing as the long-promised National Treasure 3. How might blockchain’s authentic records affect your trust in products and information?
About the Author: Aubrey R. Paris, Ph.D., is a Science and Technology Policy Adviser in the Office of the Science and Technology Adviser to the U.S. Secretary of State (STAS). She received her Ph.D. in Chemistry and Materials Science from Princeton University and B.S. in Chemistry and Biology from Ursinus College.