Which of the following key sizes does Present use?

Present is a lightweight block cipher designed to be efficient for constrained environments, such as smart cards and IoT devices. It employs a key size of 80 bits and a block size of 64 bits. The design prioritizes simplicity and speed while maintaining adequate security for typical applications. This made it suitable for environments where processing power and energy consumption are limited.

In contrast to the other key sizes presented, such as 128 bits or 256 bits, which are generally used in more complex encryption standards catering to heavy security needs and larger data sizes, 80 bits is specifically aimed at balancing efficiency with a sufficient level of security for the intended use cases of Present.