SSH keys are a cryptographic network protocol for operating network services. They are used for system to system automation and authentication, application integration, system management and other common functions. The fewest we’ve seen in the Fortune 500 companies that weve looked at has been in the hundreds of thousands of keys. These keys are almost always unused, in fact, in most cases. In one bank we found 3 million keys. Another bank found 4.5 million keys; some of the keys are 16 years old.”]