Blockchain Systems

When Satoshi Nakamoto first set the Bitcoin blockchain into motion in January 2009, he was simultaneously introducing two radical and untested concepts. The first is the “bitcoin”, a decentralized peer-to-peer online currency that maintains a value without any backing, intrinsic value or central issuer. So far, the “bitcoin” as a currency unit has taken up the bulk of the pu blic attention, both in terms of the political aspects of a currency without a central bank and its extreme upward and downward volatility in price. However, there is also another, equally important, part to Satoshi’s g rand experiment: the concept of a proof of work based blockchain to allow for public agreement on the order of transactions. Bitcoin as an application can be described as a first-to-file system: if one entity has 50 BTC, and simultaneously sends the same 50 BTC to A and to B, only the transaction that gets confirmed first will process. There is no intrinsic way of determining from two transactions which came earlier, and for decades this stymied the development of decentralized digital currency. Satoshi’s blockchain was the first credible decentralized solution. And now, attention is rapidly starting to shift toward this second part of Bitcoin’s technology, and how the blockchain concept can be used for more than just money. ...

If you are new to Bitcoin, I highly recommend checking this site: https://learnmeabitcoin.com/ Join the technological revolution that’s taking the financial world by storm. Mastering Bitcoin is your guide through the seemingly complex world of bitcoin, providing the knowledge you need to participate in the internet of money. Whether you’re building the next killer app, investing in a startup, or simply curious about the technology, this revised and expanded second edition provides essential detail to get you started. ...

If you’re looking to get started with the Ethereum protocol – or are among the many open source developers, integrators, and system administrators already working with this platform – Mastering Ethereum is the definitive book on the topic. Ethereum represents the gateway to a worldwide, decentralized computing paradigm. This platform enables you to run decentralized applications (DApps) and smart contracts that have no central points of failure or control, integrate with a payment network, and operate on an open blockchain. With this practical guide, Andreas M. Antonopoulos and Gavin Wood provide everything you need to know about building smart contracts and DApps on Ethereum and other virtual-machine blockchains. ...

RSK (Rootstock) is a Bitcoin sidechain launched in 2018 that enables smart contract functionality while using Bitcoin as its native asset, addressing Bitcoin’s limited programmability without requiring a new speculative token. Built as an evolution of QixCoin and Ethereum concepts, RSK provides a Turing-complete virtual machine (RVM) that’s highly compatible with Ethereum’s tools and dApps, offering faster transaction confirmations (around 30 seconds) while maintaining Bitcoin’s security through SHA-256D merged mining with over 40% of Bitcoin’s hash rate as of 2019. The platform uses a two-way peg system where Bitcoins become “Smart Bitcoins” (RBTC) on the RSK blockchain and can be converted back without additional costs beyond standard fees, with no new currency issuance since all RBTC originates from actual Bitcoin. RSK currently operates with a federated peg and includes protection against selfish mining through the DECOR+ protocol, while the community has planned future upgrades including storage rent, parallel transaction processing, block propagation optimizations, transaction compression protocols, support for additional VMs, and a hybrid federation/drivechain-based peg system, all documented as RSK Improvement Proposals (RSKIPs) in their GitHub repository, with RSK Labs serving as the primary development company since 2015. ...

We present Union, a trust-minimized bridge protocol that enables secure transfer of BTC between Bitcoin and Rootstock. The growing ecosystem of blockchain systems built around Bitcoin has created a pressing need for secure and efficient bridges to transfer BTC between networks while preserving Bitcoin’s security guarantees. Union employs a multi-party variant of BitVMX, an optimistic proving system on Bitcoin, to create a bridge that operates securely under the assumption that at least one participant remains honest. This 1-of-n honest approach is strikingly different from the conventional honest-majority assumption adopted by practically all federated systems. The protocol introduces several innovations: a packet-based architecture that allows security bonds to be reused for multiple bridge operations, improving capital efficiency; a system of enablers to manage functionaries participation and to enforce penalties; a flexible light client framework adaptable to various blockchain architectures; and an efficient stop watch mechanism to optimize time-lock management. Union is a practical and scalable solution for Bitcoin interoperability that maintains strong security guarantees and minimizes trust assumptions. ...