Solving the Bridge Trilemma with Zero-Knowledge Proofs: Insights from Union Co-Founder Karel Kubat

The blockchain ecosystem faces critical challenges when bridging assets and data across networks, encapsulated in the “bridge trilemma,” which encompasses security, scalability, and decentralization. Union, a platform co-founded by Karel Kubat, has emerged as a transformative force in addressing these challenges. In an exclusive interview, Kubat explained how Union leverages cutting-edge zero-knowledge proofs (ZKP) to create a universal message-passing layer that ensures both safety and scalability while facilitating advanced cross-chain functionalities.

Union’s Revolutionary Approach to Cross-Chain Interoperability

Karel Kubat, the Co-Founder and Chief Strategy Officer (CSO) of Union, described their journey to reshape blockchain interoperability. Founded three years ago, Union aims to overcome the bridge trilemma by fundamentally rethinking how blockchain networks communicate. “Traditional bridges focus primarily on asset transfers,” Kubat noted, “but Union expands these parameters by enabling more complex cross-chain functionalities like lending, borrowing, and asynchronous logic execution.”

Union’s architecture serves as a universal message-passing layer, allowing seamless interconnection between blockchains. At its core, the system aggregates state data using zero-knowledge proofs. “Union’s Layer 1 acts as a hub, interlinking different blockchains and ensuring transaction security through advanced ZKP protocols,” Kubat explained. This innovation pairs technical sophistication with scalability, making it possible to support thousands of blockchain networks.

Addressing Security Risks in Blockchain Bridges

Security remains one of the most urgent issues in cross-chain bridge development. Kubat highlighted vulnerabilities in traditional custody methods such as multi-signature (multisig) and Multiparty Computation (MPC), which expose protocols to the risk of large-scale hacking. “According to Chainlink’s reports, over $3 billion has been lost due to bridge hacks,” Kubat pointed out, emphasizing the need for more robust mechanisms.

Union mitigates these risks through a zero-knowledge light client solution. Unlike conventional security methods, light clients allow users to generate proofs rapidly—within five seconds—even on consumer-grade laptops. Kubat elaborated, “This approach ensures that cross-chain asset transfers are both secure and fast, reducing vulnerabilities and bolstering trust in the system.”

Scalable Architecture for Expanding Ecosystem Needs

Union stands out with its capacity for scalability, built to accommodate thousands of interconnected blockchains. Kubat expressed confidence in Union’s permissionless design, saying, “Whether it’s an emerging Layer 1 (L1) or Layer 2 (L2), anyone can seamlessly integrate with Union’s network without needing explicit support requests.” This flexibility not only accelerates blockchain adoption but also enhances liquidity access and asset transfer efficiency.

Union also anticipates future blockchain growth by ensuring its architecture is adaptive to new technologies. Its strategic design allows community members and developers to incorporate novel solutions effortlessly, fostering innovation and ecosystem expansion.

Strategic Collaboration with Bitcoin Ecosystem

Union’s integration strategy places the Bitcoin ecosystem at the forefront. Kubat revealed significant partnerships, including collaborations with BTCfi and Babylon to capture more than 98% of on-chain Bitcoin trading volumes. This focus underscores Union’s commitment to leveraging Bitcoin’s vast liquidity for blockchain interoperability.

One notable product offering is OBTC, a token backed by Bitcoin Liquidity Staking Tokens (LSTs). “OBTC enhances yield generation and serves additional functions like buybacks in the future,” Kubat stated. The introduction of OBTC not only aligns with Union’s vision for diversifying its product portfolio but also adds significant utility to the Bitcoin ecosystem.

Mainnet Launch: A Milestone for Blockchain Interoperability

The Union mainnet launch symbolizes a groundbreaking achievement in the blockchain sphere, combining zero-knowledge light clients with interoperability for the first time. Kubat described this milestone as transformative for the interchain ecosystem, accelerating the integration of additional blockchains. “Users now have the ability to experience Union’s capabilities firsthand,” he remarked, emphasizing the impact of this innovation.

The mainnet launch lays the foundation for deeper ecosystem connectivity, paving the way for advanced use cases like cross-chain liquidity transfer and lending. By addressing the bridge trilemma head-on, Union redefines the possibilities of blockchain interoperability.

Engagement with the Korean Blockchain Community

Korea has emerged as a significant player in blockchain technology adoption, particularly in zero-knowledge proof advancements. Kubat highlighted Union’s active collaborations with Korean partners, reflecting the region’s passionate interest in blockchain innovation. “We see Korea as a strategic market and are committed to expanding our presence within its blockchain community,” Kubat shared.

Union aims to channel this enthusiasm into tangible growth, fostering opportunities to spread awareness and integrate its technologies into Korean blockchain ecosystems.

Kubat’s Message to Korean Investors

Kubat concluded with a powerful message for Korean investors, urging them to keep a close eye on Union’s development within the liquidity and interoperability sectors. He emphasized Bitcoin-based liquidity as the next major catalyst for global blockchain growth. “Bitcoin’s liquidity potential is transformative, and Union’s advancements in interoperability will unlock key opportunities in this space,” he explained. Kubat encouraged Korean investors to actively participate as Union continues to push boundaries in the blockchain industry.

Final Thoughts

Union’s strategic vision, led by Karel Kubat, is paving the way for secure, scalable, and decentralized blockchain interoperability. Through its groundbreaking use of zero-knowledge proofs, adaptive architecture, and targeted collaboration with the Bitcoin ecosystem, Union addresses critical challenges in the blockchain world, solidifying its role as a leader in the next-generation interchain landscape. With the recent mainnet launch, Union not only tackles the bridge trilemma but opens doors for an expansive global blockchain ecosystem.