Very valid concerns, and the Turkish approaches, significantly led by the folks from my alma mater (sorry to take pride in it), are the following:
Unique and customized digital wireless communications systems: implemented with indigenous techniques, protocols, critical semiconductor devices and ICs (including baseband microprocessors and controllers, transmitters, receivers, multiplexers etc.), sensors, coding (including OS, programming language, machine hexcodes etc.), hardware, software, encryption mechanisms, EM algorithms, power amplifiers, ultra-fast and high-power microwave and RF devices, antenna systems, signaling mathematics etc. These are prerequisites to make it extremely difficult for the enemy to decode your unknown and unearthed signals and systems within a tremendously fast paced (in the realm of milli seconds) war environment.
Indigenous avionics, radars, WVR/BVR missiles, links etc.: smart knowledge-based intelligent techniques and implementations to take it farther away from your enemy.
Bottom-line: continuous R&D to see before your enemy sees you and to hit before your enemy hits you. Purchase any critical defense related gadgets from a 3rd party, and you're fuckn dead..