What is documented is that she was in the environment, with the credentials, at the time when the most consequential work in that area was being done.

The Cold War context is part of why the secrecy was so thorough and so durable.

These were not commercial secrets or competitive business secrets.

They were military secrets, strategic secrets, secrets on which the American government believed the country’s survival might depend.

The engineers and mathematicians who held those secrets were held to a standard of discretion that has no civilian equivalent, and they mostly maintained that standard for their entire lives.

Gender, Mathematics, And The Invisible Woman