Victorian use of flowers as a means of covert communication bloomed alongside a growing interest in botany and the relationship between plants, animals, and humankind.

It is likely that covert communications between the two nations' militaries on nuclear issues, unknown to and sometimes contradicting civilian leaders' wishes, began at this time.

The authors suggest there are a huge number of applications for this technology, including remote medical monitoring, biological/chemical sensing, human-machine interface, and covert communications.

All three submarines used covert acoustic communications.

It had his e-mail address, the most useful tool for covert communications ever invented.

D'tran and Rosen would continue their covert communications for years afterward in similar fashion, never meeting in person.

"We believe there will be blue laser applications in covert communications, biological warfare and missile threat warning systems."

They're carrying military coms designed for planetary ranges and covert communications, so they're not tied into the system-wide net.

One-time pads were employed by Soviet espionage agencies for covert communications with agents and agent controllers.

Comms op:A possibly covert communications mission.