Under the Freedom of Information Act, messages sent by government employees and officials can be disclosed in response to a FOIA request. If an individual whose communications were covered by FOIA encrypted their messages with a third-party program (e.g. GPG) before sending them from their government email address, what would happen if those messages were subsequently requested?
The emails would be available, technically, but they'd be unreadable because of the encryption. Would the FOIA prevent further investigation? Or would the requester be able to compel the employee to, say, disclose their private key*?
*I'm assuming that the sender encrypted the message to both their own and the receiver's key here, but it's interesting to think about what would happen if they only used the recipient's key. Would the request then be able to compel disclosure of the recipient's private key?