Blockchain Health Diaries by Rekha

  In the age of digital transformation, healthcare is undergoing a profound change. At the heart of this evolution lies a critical question: Are hospitals prepared to transition from centralized Electronic Health Record (EHR) systems to decentralized architectures powered by blockchain? The answer is both promising and complex . 🔍 Why Rethink Centralized EHRs? Old EHR systems keep patient records in one place, controlled by each hospital or clinic. This has worked for many years, but it has some big problems. If the system breaks or is hacked, no one can access the records. Different hospitals can’t easily share information, so patients may have to repeat tests or give the same details again when they go to a new doctor. Also, patients don’t have much control over their own health data. 🌐 Enter Decentralized EHRs: Blockchain to the Rescue New EHR systems using blockchain work in a very different and better way. They keep health records safe by locking them with special codes and...

 As healthcare becomes more digital, blockchain is emerging as a powerful way to manage medical records — securely, transparently, and with patients in control. But here’s the big question: ❓ Can blockchain-based systems follow laws like HIPAA (USA), GDPR (EU), and NDHM (India)?  ✅ Yes — but only with the right design. Blockchain can comply with healthcare laws if it is built to: 🔐 Protect patient privacy 🧑‍⚕️ Control who can access what data 🧾 Keep records secure and unchangeable 👩‍💼 Give patients ownership of their health data 🔒 A Simple Guide to Healthcare Compliance Rules Different healthcare laws around the world focus on protecting people’s health data. In the US, HIPAA makes sure that patient information is kept safe, only shared with permission, and can be tracked if accessed. In Europe, GDPR gives people more control over their personal data — they can ask for their data to be deleted, moved, or shared only with clear permission. In India, ...

Blockchain technology has changed the way we handle trust, ownership, and control — without needing a middleman like a bank. But as more people use blockchains like Ethereum, it’s getting crowded. This means slower transactions and higher fees. So how do we fix this? That’s where Rollups come in. 🧱 What Are Rollups? Rollups are tools that help blockchains handle more transactions. Think of them as a “helper lane” on a busy road. Instead of everyone driving on the main highway (the main blockchain), some cars take the helper lane (the rollup), which makes everything move faster. Rollups bundle (or “roll up”) a bunch of transactions together and send them to the main blockchain in one go. This saves space and cuts down on costs. 🛠️ How Do Rollups Work? Here’s how they work in simple steps: Transactions happen on Rollups instead of directly on Ethereum. These transactions are bundled together . The rollup then sends a summary of all those transactions to Ethereum. Ether...

  As more people use cryptocurrency, it brings smart ideas — but also some dangers. One big danger in blockchains like Bitcoin is called a 50% attack (also known as a 51% attack). So, what is a 50% attack? It happens when someone takes control of more than half of the network’s computer power . With that much power, they can: Stop or slow down other people’s transactions Change their own transactions Spend the same coin twice (called double spending ) This kind of attack can make people lose trust in the system . That’s why it’s very important to watch out for this , especially in smaller or newer blockchains . . 🔍 What is a 50% (or 51%) Attack? A 50% attack happens when one person or group gets control of more than half of a blockchain’s computing power (also called hash rate ). With this much power, they can: Change or control the blockchain Stop other people’s transactions from going through Undo their own payments and use the same coins again (c...

  As blockchain adoption spreads across industries — from finance and healthcare to supply chain and digital identity — it faces one critical roadblock: the Blockchain Trilemma . First identified by Ethereum’s Vitalik Buterin, the trilemma refers to the difficulty of achieving Decentralization, Security, and Scalability simultaneously. Most blockchains today can only fully deliver two. But the good news? We're seeing promising innovations that aim to overcome this challenge. 🧩 Layered Architectures Layer 2 solutions like Rollups (Optimistic and ZK-Rollups) are helping major networks like Ethereum scale without compromising decentralization. They process transactions off the main chain and then finalize them securely on Layer 1. ✅ Better scalability ✅ Maintains security and decentralization ⚙️ Sharding Ethereum 2.0 introduces sharding — splitting the blockchain into smaller pieces ("shards") that work in parallel. This boosts scalability while keeping decentraliza...

 Blockchain technology is growing beyond just cryptocurrencies — it's now being used in apps, healthcare, supply chains, and more. At the heart of blockchain are two key systems: Proof of Work (PoW) and Proof of Stake (PoS) . These help keep the network secure and trusted. 🛠️ Proof of Work (PoW): The Old Guard Proof of Work (PoW), used by Bitcoin, was the first method to secure blockchain networks. It works by having miners solve complex puzzles to verify transactions, making the system safe and reliable. However, it uses a lot of energy, which raises environmental concerns. Over time, mining has also become more centralized, with large companies dominating the process. Plus, PoW can be slow and costly, making it harder to scale for modern use. 🔮 The Future of PoW In the future, PoW may become more eco-friendly by using renewable energy and better hardware. Some blockchains might mix PoW with PoS to improve speed and reduce energy use. While many are moving away from PoW, it ...

 Welcome to my blog! I’m Rekha — a tech enthusiast, PhD researcher in blockchain for healthcare, and someone who believes it’s never too late to start something new. This space will be my digital diary to: • Explore how blockchain is transforming electronic health records (EHR) • Share simple tech tips for everyday users • Reflect on my personal growth, life after 50, and my academic journey If you’re someone curious about how technology can create impact — or if you’re navigating midlife with purpose — you’ll feel at home here. Let’s explore, question, and grow together. Stay tuned! 🖋️ — Rekha