behind closed doors; behind-the-scenes; (under the veil of) secrecy
secret base; hideout; hidden position
company secret; industrial secret; trade secret
behind closed doors; behind-the-scenes; (under the veil of) secrecy
to betray a secret; to reveal a secret
secret meeting; secret conference
secretive; mysterious; furtive; stealthy; clandestine; sneaky
confidentiality; nondisclosure
confidential document; confidential paper; classified document
secret meeting; secret conference; closed-door session
privacy of communications
leaking of a secret; leakage of a secret
leaking of a secret; leakage of a secret
secret vote; secret ballot
privacy of correspondence
specially designated secret
recording audio without consent; secret recording
private key (cryptography); secret key
private key (cryptography); secret key
secret will and testament; sealed envelope will
Yalta Agreement (secret American-British-Soviet agreement wherein the Soviets agreed to attack Japan within three months of the German surrender; February 11, 1945)
secure computation; secure computing
the crime of revealing a secret; breach of confidence