Overview of classified information procedures act (CIPA) (see Classified evidence in a court martial):
The Classified Information Procedures Act: What It Means
CIPA outlines the relevant procedure that allows the government to protect information pertaining to national security at all the stages of a trial.
This includes during discovery. It reaffirms the authority of the executive branch to decide that public disclosure of classified information will not be made during a criminal proceeding, and establishes the procedure to follow during a trial involving such information.
CIPA requires that a defendant notify the government of its intent to reveal confidential information during a trial. At that point, the government can decide to either seek a ruling that some or all of the confidential information is not relevant, seek a ruling to allow the substitution of the confidential information with non-confidential information or a redacted copy, or admit the facts.
CIPA does not change the normal requirements of relevance of proof. It allows the government to invoke its privilege and thereby refuse to divulge information that would be relevant.