Cardano founder Charles Hoskinson has once again drawn attention to the XRP Ledger (XRPL) after revisiting its consensus design during a live X Spaces session with David Schwartz. Hoskinson has offered fresh praise for the network’s architecture and reinforced a growing narrative of mutual respect between two of crypto’s most influential ecosystems. The Cardano founder, known for his research-driven approach to blockchain design, highlighted the XRPL’s consensus model as a “well-reasoned system,” emphasizing its efficiency, low-latency settlement structure, and long-standing focus on payments infrastructure. His remarks reflect a broader reassessment of early blockchain systems as institutional adoption and tokenization accelerate across the digital asset sector. Three days before the live session, Schwartz had joined the XRP Ledger Foundation board as an honorary member. The XRP Ledger, originally launched in 2012, uses a unique Federated Byzantine Agreement (FBA) consensus mechanism that enables transactions to settle in just a few seconds. This works without relying on proof-of-work or proof-of-stake mining. Instead, it depends on a network of trusted validator lists (UNLs) to achieve agreement. This design has long been praised for its speed and debated for its trade-offs in decentralization. A big week for Schwartz and why the timing matters The XRP Ledger Foundation announced a new leadership team on May 8, naming Brett Mollin as executive director. Denis Angell was named chief technology officer, Rene Huijsen director of operations, and Hussein “Vet” Zangana director of community. The board added Schwartz three days later because he understands the original design decisions. And three days after that, Hoskinson publicly praised the foundations that Schwartz had built in his early years. What brought Hoskinson back to XRPL? Hoskinson and his team are working on a new project called the Midnight glacier drop , and they needed to include the XRPL as one of the networks. Midnight is a privacy-focused blockchain built on Cardano, while a glacier drop is a type of token distribution. Schwartz comes in as a consultant, helping Cardano engineers navigate the technical details of building with XRPL. For the first time since 2013 or 2014, Hopkinson found a reason to review XRPL’s design. He read a paper on the Ledger’s consensus approach and looked at how it handles Byzantine agreement. In his own words, Hopkinson said, “The whole UNL concept is pretty nifty, especially if you have negative UNLs to achieve liveness again. So, there were some nice things there, and it’s just a well-reasoned system for what you guys put together.” What is the UNL, and why has it been controversial? The UNL, or Unique Node List, is a list of trustworthy computers that every computer participating in the XRP Ledger can choose. Bitcoin uses Proof-of-work, in which computers race to solve complex mathematical puzzles. Whoever solves it first earns the right to add the next batch of transactions. The XRPL works differently because nodes compare notes and reach an agreement. XRPL Foundation usually recommends a UNL of verified and vetted validators worldwide. What Hopkinson praised is the negative UNL. When trusted validators must agree before confirming a transaction, you could end up waiting indefinitely if some of them disappear. The negative UNL removes unreliable validators from the process, and that’s what Hopkinson said was well-reasoned. What has Schwartz been defending all along? Justin Bons, the founder and chief investment officer of Cyber Capital, said XRPL is essentially more centralized because the people who control the UNL control the network. For years, Schwartz pushed back against such theories, saying the UNL acts as a preventive measure against denial-of-service attacks. These attacks happen when an unlimited number of random validators flood the network. Schwarts argues that the list does not give Ripple or anyone else the power to censor any transactions. According to Bons, true decentralization works like Bitcoin mining, where anyone in a system can become a validator without permission. However, Schwarts thinks that comes with risks and that the UNL provides a workable middle ground. Hopkinson is one of the biggest critics in the space, and he built Cardano on a different principle than the one behind XRPL. The fact that he commended the UNL after studying it builds on Schwartz’s defense against Bons. Don’t just read crypto news. Understand it. Subscribe to our newsletter. It's free .
