British Encryption Startup Arqit Overstates Its Prospects, Former Staff and Others Say

A U.K. cybersecurity startup rocketed to a multibillion-dollar valuation when it listed publicly last fall on the promise of making encryption technology that would protect the defense industry, corporations and consumers alike from the prying eyes of next-generation computer systems. Founder and Chief Executive David Williams told investors at the time that his company, Arqit Quantum Inc., had an “impressive backlog” of revenue and was ready “for hyperscale growth.”

But Arqit has given investors an overly optimistic view of its future revenue and the readiness and workability of its signature encryption system, according to former employees and other people familiar with the company, and documents viewed by The Wall Street Journal.