[6] Gold Codes are generated daily and provided by the National Security Agency (NSA) to the White House, The Pentagon, United States Strategic Command and TACAMO.
The concept behind the codes is that they permit the president to present positive identification of being the commander-in-chief and thereby authenticate a launch order to the National Military Command Center (NMCC).
Before the order can be followed by the military, the president must be identified using a special code issued on a plastic card, nicknamed "the biscuit".
[9] The authentication is conducted between the president and the NMCC's deputy director of operations, using a challenge code of two phonetic letters.
[11][12][13][14] Nuclear-defense policy expert Franklin Miller argues that the president has almost singular authority to initiate a nuclear attack; while the secretary of defense is required to verify the order, they cannot veto it.