________ is efficient enough in processing power and RAM requirements to be used on small devices, such as PDAs and cell phones.

• A. 3DES
• B. AES
• C. Both A and B
• D. Neither A nor B

Answer: (B)

When you’re deploying encryption on small devices, you need an algorithm that delivers strong security without demanding a lot of processing power or memory. AES fits that need well because it was designed for efficient software and hardware implementations. It operates on a 4×4 byte state and uses a fixed number of rounds that scales with key length (10 rounds for 128-bit keys, 12 for 192-bit, 14 for 256-bit). This structure allows highly optimized code with a small footprint and fast execution on limited CPUs, making it practical for devices with modest RAM and processing power.

3DES, by contrast, runs DES three times, effectively tripling the amount of work per encryption. That means more CPU cycles and more memory for the key schedule, so it’s noticeably slower and less suited to constrained devices. DES itself has fallen out of favor due to weak key lengths, and 3DES inherits that drawback while adding performance costs.

So AES is the better choice for small devices, balancing security with the resource constraints those devices impose.