Cardinal Cryptography

Cardinal Cryptography is a European venture studio and consulting firm based in Poland, focused on blockchain, fintech, and cryptography. The company has built Aleph Zero, a layer 1 blockchain with built-in privacy features and instant finality that has maintained 99% uptime over four years and attracted over 50 teams to develop on it. More recently, Cardinal shifted focus to Blanksquare, a privacy-first infrastructure layer powered by Zero Knowledge technology that integrates onchain privacy into wallets and decentralized applications. The team comprises cryptographers, mathematicians, engineers, designers, and marketers—not a typical outsourcing shop. Cardinal has won multiple awards, including Top 5 Europe's Top Blockchain Startup of the Year and Best Infrastructure Project.

Services and capabilities

Cardinal specializes in embedding Zero Knowledge privacy into DeFi applications and cryptocurrency wallets. The firm offers two primary models: helping teams design and integrate privacy features into existing products, or providing dedicated software development teams for longer-term builds. They have authored the Shielder SDK and Blanksquare, both of which serve as templates for privacy-preserving infrastructure. The company focuses specifically on addressing privacy gaps on transparent blockchains, where transaction details are publicly visible by default.

Their technical work spans blockchain consensus protocol design (they co-authored the Highway consensus protocol whitepaper with Casper Labs), validator infrastructure setup, and privacy-enhancing cryptography. Cardinal positions privacy as foundational rather than bolted-on, designing it into the architecture from the start.

Notable work

Cardinal built Aleph Zero, which reached a Top 100 market ranking and maintains 99% uptime. The platform has attracted over 50 development teams. They assisted Deutsche Telekom in launching validator node infrastructure for Aleph Zero. The firm contributed to Sovryn, a non-custodial Bitcoin trading and lending platform, and created the visual identity for Coinbar Group, a blockchain advisory and investment firm. Cardinal also supported the Kosciuszko Institute during their CYBERSEC European Forum.

How they work

Cardinal operates as both a venture studio (building and launching its own products like Aleph Zero and Blanksquare) and a consulting firm taking on client projects. They describe their approach as starting with mathematics and science before moving to implementation. The firm works with clients on either fixed integration projects or provides dedicated development teams for ongoing work. No specific pricing or engagement timelines were mentioned in their materials.

Team and credentials

Cardinal is an award-winning team of cryptographers, computer scientists, and blockchain developers. The company has won Top 5 Europe's Top Blockchain Startup of the Year, Best Infrastructure Project, and Startup of the Year (2021). They were finalists in the Global FinTech Hackcelerator and won the European FinTech Hackcelerator. Team size was not specified. The firm is based in Poland.