The National Security Agency did a surprising thing last August – it suddenly declared that the algorithms it had spent a decade telling the world were the best way to lock up secret data weren’t safe anymore. The reason? The danger of quantum computers.

The NSA has now released more detail on those fears. “There is growing research in the area of quantum computing, and enough progress is being made that NSA must act now,” says a new Q&A-style document on the problem. It’s aimed at companies and government departments working with sensitive data.