Michael Gao, the co-founder of California-based start-up Fabric Cryptography, makes a bold claim. “We’re going to do for cryptography what Nvidia has done for artificial intelligence (AI),” he says.

Cryptography is an obscure discipline. Unless you're in big tech, a university or a research organization, you're unlikely to meet its practitioners. Even then, you might have to search to find them.

Quantum computing is ready for mainstream deployment, where it already is being tapped to resolve real-world business challenges. Use of the technology to crack cryptography and encryption codes, ...