Lowering power consumption while improving functionality is the new Holy Grail for consumer technology designers. This is especially true in areas like wireless devices where gadgets such as mobile phones and tablets continue to shrink in size, yet are expected to perform more and more functions. Being able to reduce battery drain is very important.

Using less energy, though, doesn’t come without its own set of risks; the biggest is network security. Next-generation devices use less power, while current network security methods require more power than these systems can provide.

One recent study could lead to more protected communications thanks to a new mathematical formulation that measures the energy efficiency of network security.

Previous research has attempted to solve this by looking for ways to increase the power in wireless devices, so that conventional security methods will have enough power to operate. However, Bo Bai and his team of researchers suggest that it may be more practical to make the process used to secure messages more efficient itself. In an article in IEEE Transactions on Communications, they present an algorithm that measures the “secure energy efficiency (EE),” the most efficient use of energy when relaying messages over a decode-and-forward relay channel.


A multi-relay network with an eavesdropper.

Current wireless network security encrypts and decrypts messages through various channels. In a decode-and-forward relay channel, for example, the relay node will decode the received signal from the original source, then forward the information to the destination node. If there are multiple relay nodes, these nodes can cooperate to forward the information. This practice prevents eavesdroppers from accessing the information while it is being transferred. The secure EE algorithm proposed captures the optimal point at which the energy is used with highest efficiency, so that devices are the most secure with the least amount of power consumed.

“We’re very excited about this research because of its brand new perspective,” said Bai, lead researcher of the project. “As wireless communications becomes more energy-efficient, network security must evolve with it. We’re hoping to see our results used in future network design in physical layer security.”

Solving the secure EE mathematical problem is extremely difficult, so the researchers developed a suboptimal solution scheme to simplify it that applies some mathematical methods, including mixed integer programming, fractional programming, dual decomposition and DC programming. The proposed solution is a multi-layer iterative algorithm that solves the secure EE by converting the primal problem into simplified problems so that the secure EE ratio is easier to find.

The researchers have evaluated the proposed scheme numerically and have evidence that the scheme should work. They have started building a prototype system to test it with an actual wireless network.

You can also find more articles about “Wireless Communications” in IEEE Xplore.