Mostafa Ahmed Awwad, 36, a civilian who worked at the Norfolk, Virginia shipyard where the highly sophisticated sub is being built, offered the information to an undercover FBI agent posing as Egyptian intelligence in September.
Awwad, who entered his plea before US District Judge Raymond Jackson, had offered a USB drive with some of the details on the cutting-edge supercarrier's layout.
He also offered to supply the rest of the information on the ship, which can carry some 4,000 sailors, to Cairo.
Assistant FBI Director Randall Coleman stressed that "we prevented the loss of billions of dollars in research costs and the exposure of potential vulnerabilities to our newest generation of nuclear aircraft carrier."
Prosecutors are seeking a prison sentence of eight to 11 years.