It is very cut and dry:

(a) Whoever knowingly and willfully communicates, furnishes, transmits, or otherwise makes available to an unauthorized person, or publishes, or uses in any manner prejudicial to the safety or interest of the United States or for the benefit of any foreign government to the detriment of the United States any classified information—
(1) concerning the nature, preparation, or use of any code, cipher, or cryptographic system of the United States or any foreign government; or
(2) concerning the design, construction, use, maintenance, or repair of any device, apparatus, or appliance used or prepared or planned for use by the United States or any foreign government for cryptographic or communication intelligence purposes; or
(3) concerning the communication intelligence activities of the United States or any foreign government; or
(4) obtained by the processes of communication intelligence from the communications of any foreign government, knowing the same to have been obtained by such processes—
Shall be fined under this title or imprisoned not more than ten years, or both.
(b) As used in subsection (a) of this section—
The term “classified information” means information which, at the time of a violation of this section, is, for reasons of national security, specifically designated by a United States Government Agency for limited or restricted dissemination or distribution;

The terms “code,” “cipher,” and “cryptographic system” include in their meanings, in addition to their usual meanings, any method of secret writing and any mechanical or electrical device or method used for the purpose of disguising or concealing the contents, significance, or meanings of communications;

The term “foreign government” includes in its meaning any person or persons acting or purporting to act for or on behalf of any faction, party, department, agency, bureau, or military force of or within a foreign country, or for or on behalf of any government or any person or persons purporting to act as a government within a foreign country, whether or not such government is recognized by the United States;

The term “communication intelligence” means all procedures and methods used in the interception of communications and the obtaining of information from such communications by other than the intended recipients;

The term “unauthorized person” means any person who, or agency which, is not authorized to receive information of the categories set forth in subsection (a) of this section, by the President, or by the head of a department or agency of the United States Government which is expressly designated by the President to engage in communication intelligence activities for the United States.