Why is lightweight cryptography designed for modern systems?

• A. To require higher energy usage
• B. To increase key sizes unnecessarily
• C. To avoid interoperability
• D. To operate on devices with constrained resources

Answer: (D)

Lightweight cryptography targets security that fits small, resource-limited devices. Modern systems like IoT sensors, microcontrollers, wearables, and smart cards have limited processing power, memory, and battery life. Traditional cryptographic schemes can be too heavy for these devices, causing slow performance, higher energy consumption, or even infeasibility. By prioritizing small code size, low memory use, and efficient computations, lightweight cryptography provides acceptable security without draining resources, enabling secure communication and operations on constrained hardware. The other statements don’t fit because increasing key sizes or demanding more energy would worsen performance on limited devices, and avoiding interoperability would hinder real-world deployment.